Roofing Resources
Roofing Glossary: 250+ Roofing Terms Explained in Plain English
Estimates, insurance paperwork and inspection reports are full of words nobody explains. This glossary defines 252 of them in plain English, from drip edge and ice barrier to recoverable depreciation, sworn statements and NDL warranties, for homeowners, property managers and anyone comparing roofing bids.
Written by Stellar Roofing Company, a licensed Michigan roofer in Kentwood. Updated September 24, 2026.
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How to Use This Glossary
Terms are listed A to Z. Use the letter bar to jump, or your browser's find (Ctrl+F or Cmd+F) to search the page. Every term has its own link, so you can send someone straight to one definition. For example, /roofing-resources/roofing-glossary#ice-dam.
The glossary covers steep-slope residential roofs (shingles, flashing, underlayment, ventilation and decking), low-slope and commercial systems (TPO, EPDM, PVC, modified bitumen, built-up roofs and coatings), metal, slate, tile and cedar, how roofs are measured, what estimate and contract terms mean, insurance claim vocabulary, and the Michigan-specific rules and weather that shape roofs here.
Code references are to the Michigan Residential Code, which as of 2026 is the 2015 edition (adoption of the 2021 update was blocked by court order in July 2025). Your local building department has the final word on what applies to your project.
Insurance, lien and contract definitions here are general information, not legal, insurance or tax advice. Your policy and contract language control; for a specific situation, talk to your agent, adjuster or an attorney.
Mix-Ups
The Most-Confused Roofing Terms
These pairs trip up homeowners, and sometimes the estimates they receive. Knowing the difference makes it much easier to compare bids and read an insurance scope.
Drip edge vs. Gutter apron
Both are metal at the roof edge. Drip edge is an L- or T-shaped strip that kicks water away from the fascia and is required by code on shingle roofs at eaves and rakes. Gutter apron is shaped to reach down into the gutter so water cannot sneak behind it. At the eaves a roofer typically uses one or the other depending on the gutters; the rakes always get drip edge.
Underlayment vs. Ice and water shield
Underlayment is the general backup layer over the whole deck, usually synthetic sheet that is nailed down and sheds water. Ice and water shield is a specific kind of underlayment that sticks to the deck and seals around nails, so it can hold back water that backs up from an ice dam. It goes where water pools or backs up: eaves, valleys, around chimneys and penetrations.
Ice and water shield vs. Ice barrier
Same material, different vocabulary. Ice barrier is the code's word for the required protection at the eaves (from the edge to at least 24 inches inside the exterior wall line). Ice and water shield is the product people use to meet it, and roofers also install it in valleys and other spots the code does not require.
Actual cash value (ACV) vs. Replacement cost value (RCV)
RCV is what it costs to replace the roof new today. ACV is RCV minus depreciation. On an RCV policy you usually get the ACV check first and the held-back depreciation after the work is done. On an ACV policy or roof payment schedule, that depreciation is gone for good.
Recoverable depreciation vs. Non-recoverable depreciation
Recoverable depreciation is money the insurer holds back until you prove the work was completed, then pays. Non-recoverable depreciation is never paid. Your policy type decides which you have, and recoverable depreciation often has a deadline.
Roof-over vs. Tear-off
A roof-over installs new shingles over the old layer; a tear-off strips to the deck first. Michigan code bans a roof-over when there are already two layers or the existing roof or deck is deteriorated. A tear-off costs more up front but lets the crew see and fix the deck, flashing and ventilation.
Soffit vs. Fascia
Fascia is the vertical board along the roof edge that the gutter hangs on. Soffit is the horizontal underside of the overhang, between the fascia and the wall. Soffit vents are the attic's intake; fascia is just trim.
Pitch vs. Slope
In everyday roofing talk they mean the same thing: inches of rise per 12 inches of run, like 6/12. Technically pitch is rise over the full span, so a 6/12 slope is a 1/4 pitch, but almost nobody in the field uses that meaning anymore.
Manufacturer warranty vs. Workmanship warranty
The manufacturer warranty covers defects in the material and, on enhanced system warranties, some labor. The workmanship warranty is the roofer's own promise on the installation. Most roof failures are installation-related, so the workmanship warranty and the company behind it matter as much as the shingle brand.
Sworn statement vs. Lien waiver
A sworn statement lists everyone who supplied labor or materials and what they are owed. A lien waiver is a signed release of lien rights for amounts paid. You use the sworn statement to know whose waivers to collect.
EPDM vs. TPO
Both are single-ply flat roof membranes. EPDM is a black synthetic rubber with taped or glued seams. TPO is usually white, with seams melted together by hot air. The right choice depends on the building, the budget, roof traffic and what it sits over, not on one being universally better.
Quick Reference
Roofing by the Numbers
The figures that come up most often in estimates, inspection reports and code discussions. Code numbers are from the Michigan Residential Code (2015 edition); product ratings are from the named test standards.
| Term | The number | What it means |
|---|---|---|
| Square | 100 sq ft of roof surface | A 25-square roof is about 2,500 sq ft of roof surface (not floor area). |
| Bundle | Often 3 per square | Common for many architectural shingles; heavier products may take 4 or more. |
| Slope factor, 4/12 | about 1.054 | Multiply the flat footprint by this to get sloped roof area. |
| Slope factor, 6/12 | about 1.118 | A 2,000 sq ft footprint at 6/12 is about 2,236 sq ft of roof. |
| Slope factor, 8/12 | about 1.202 | Steeper roofs have noticeably more surface than their footprint. |
| Slope factor, 12/12 | about 1.414 | A 45-degree roof: about 41 percent more surface than footprint. |
| Waste factor | roughly 10% and up | Around 10% on simple gables, more on hips and cut-up roofs. |
| Low-slope roof | 3:12 or less | Needs a membrane system rather than shingles. |
| Minimum shingle slope | 2:12 | Between 2:12 and 4:12, code requires a double layer of underlayment. |
| Ice barrier | 24 in. inside the wall line | Measured from the eave to at least 24 inches inside the exterior wall. |
| Attic ventilation | 1:150 (1:300 in some cases) | Net free vent area per square foot of attic floor under the residential code. |
| Layer limit | 2 layers | Michigan Residential Code R908.3.1.1: no re-cover over two existing layers. |
| Chimney cricket | wider than 30 in. | Chimneys wider than 30 inches that do not sit on the ridge need a cricket. |
| Class 4 impact (UL 2218) | 2 in. steel ball from 20 ft | The highest impact rating for roof coverings. |
| Wind, ASTM D3161 Class F | 110 mph | Older fan-based shingle wind test. |
| Wind, ASTM D7158 Class H | 150 mph | Newer uplift-based shingle wind test. |
| Ponding water | 48 hours | Water still standing 48 hours after rain is commonly treated as ponding. |
| Home solicitation cancel | 3 business days | Michigan's window to cancel most sales made at your home. |
Want to run the math on your own roof? The roofing calculators handle squares, slope factors and waste.
A to Z
The Roofing Glossary
- Acrylic Roof Coating
- A water-based elastomeric coating rolled or sprayed over an existing low-slope roof to add reflectivity and a new weathering surface. It is economical and bright white, but it generally tolerates standing water less well than silicone, so it suits roofs that drain well.
- See also: Commercial roof coatings, Silicone Roof Coating, Ponding Water
- Actual Cash Value (ACV)
- Also called: ACV
- An insurance settlement basis: the cost to replace the damaged roof minus depreciation for its age and wear. On an ACV policy or endorsement, the depreciation is not paid back later, so an older roof can produce a much smaller check than the cost of the new roof.
- See also: Replacement Cost Value (RCV), Depreciation, Insurance roof claims
- Adjuster
- Also called: Insurance adjuster, field adjuster, desk adjuster
- The person who investigates a claim and decides what the policy pays. A staff adjuster works for the insurer, an independent adjuster is hired by the insurer on contract (common after big storms), and a desk adjuster reviews photos and estimates without visiting.
- See also: Public Adjuster, Reinspection, Insurance FAQ
- Aerial Measurement Report
- A roof measurement produced from satellite or aerial imagery that lists squares, pitches and linear feet of ridges, valleys, eaves and rakes. It is a solid starting point, but trees, recent additions and multiple layers can throw it off, so a good estimator still checks it on site.
- See also: Square, Linear Foot, Roofing calculators
- Aggregate
- Gravel or crushed stone embedded in or laid over a low-slope roof, most often the top surface of a built-up (tar and gravel) roof or the ballast on a loose-laid membrane. It shields the membrane from sunlight and adds weight against wind.
- See also: Built-Up Roofing (BUR), Ballast
- Algae Streaks
- The black or dark-green streaks common on north-facing shingle slopes, caused by airborne algae feeding on the shingle surface. They are mostly cosmetic. Many shingles now carry algae-resistant granules that contain copper, and a gentle low-pressure cleaning (never a pressure washer) removes existing streaks.
- See also: Moss, Granules, Roof maintenance checklist
- Alligatoring
- A pattern of deep cracks that looks like alligator hide, found on aged asphalt surfaces such as built-up roofs, old roll roofing and worn coatings. It means the asphalt has dried out and lost flexibility, and water can soon reach the layers underneath.
- See also: Built-Up Roofing (BUR), Flat roof repair
- Allowance
- A contract line that sets aside a budgeted amount for something that cannot be priced until the job is underway, such as replacing rotted decking. Read how an allowance is reconciled: whether unused money is credited back and what happens if the real cost goes over.
- See also: Unit Price, Change Order, How to read a roofing estimate
- Appraisal Clause
- A provision in most homeowners policies that lets either side demand an independent appraisal when you and the insurer agree the damage is covered but disagree on the dollar amount. Each side hires an appraiser and an umpire settles disputes. It resolves price, not whether something is covered.
- See also: Supplement, Insurance FAQ
- Apron Flashing
- Also called: Headwall flashing, front flashing
- A continuous piece of metal flashing where the top of a lower roof meets a vertical wall or the downhill face of a chimney. It laps over the shingles below and runs up the wall behind the siding or under counterflashing.
- See also: Step Flashing, Counterflashing, Flashing issues
- Architectural Shingle
- Also called: Dimensional shingle, laminated shingle
- The most common residential shingle today. Two or more layers are laminated together to give a thicker, shadowed look, and they are heavier and generally longer-rated than three-tab shingles. Because of that layered profile, laying new shingles over them flat is very hard to do well.
- See also: Three-Tab Shingle, Asphalt shingles
- Asphalt Shingle
- Also called: Composition shingle, comp shingle
- A roofing shingle made of a fiberglass mat coated with asphalt and topped with ceramic-coated mineral granules. It is the dominant steep-slope roof covering in Michigan because it balances cost, looks and service life.
- See also: Asphalt shingles, Architectural Shingle, Roof lifespan comparison
- Attic Air Bypass
- Also called: Attic air leak
- Any gap that lets warm, moist house air leak into the attic: around recessed lights, plumbing stacks, bath fans, chimneys, attic hatches and top plates. Bypasses are a leading cause of ice dams, attic frost and mold, and sealing them often matters as much as adding vents.
- See also: Ice Dam, Attic Frost, Mold in the attic
- Attic Frost
- Frost that builds up on the underside of the roof deck and on nail tips during cold weather, from moist indoor air reaching a cold attic. When it warms up the frost melts all at once and drips, which homeowners often mistake for a roof leak.
- See also: Attic Air Bypass, Ventilation, Ventilation problems
- Baffle
- Also called: Rafter vent, insulation baffle
- A channel of foam, cardboard or plastic stapled between rafters at the eaves that keeps attic insulation from blocking the soffit vents. Without baffles, blown insulation often seals off the intake air and ventilation stops working.
- See also: Soffit Vent, Intake Vent, Ventilation problems
- Ballast
- Weight, usually river rock or concrete pavers, that holds a loose-laid single-ply membrane in place instead of fasteners or adhesive. A ballasted roof has to be structurally able to carry the extra load, and the stones must be moved to find or repair a leak.
- See also: Mechanically Attached, Fully Adhered, Flat roof systems
- Base Flashing
- On a low-slope roof, the membrane that turns up from the roof surface onto a wall, curb or parapet to seal that joint. It is usually covered at the top by counterflashing or a termination bar so water cannot run behind it.
- See also: Counterflashing, Termination Bar, Parapet
- Base Sheet
- The first ply laid on a low-slope deck in a built-up or modified bitumen system. It is fastened or adhered to the deck, and the remaining plies and the cap sheet are bonded on top of it.
- See also: Cap Sheet, Modified Bitumen, Built-Up Roofing (BUR)
- Batten
- A wood or metal strip fastened across the roof that some coverings, including many tile, slate and some metal systems, hang from or fasten to. Battens can also create a small air space under the roof covering.
- See also: Tile roofing, Slate roofing
- Blistering
- Raised bubbles in a roof surface. On shingles, small blisters usually come from moisture or gases trapped during manufacturing and made worse by heat; when they pop they leave bare spots. On membranes and built-up roofs, blisters are pockets of trapped air or moisture between layers that can split open.
- See also: Granule Loss, Granule loss, Flat roof repair
- Blow-Off
- Shingles that wind has torn loose and carried away, often along an edge, ridge or rake where uplift is strongest. Blow-offs are frequently traced to shingles that never sealed, or to nails driven above the nail line.
- See also: High Nailing, Sealant Strip, Missing shingles, Wind damage
- Box Vent
- Also called: Static vent, turtle vent, louver vent
- A low, square exhaust vent with no moving parts, installed near the ridge in groups. Box vents let warm attic air escape by natural convection and are common where a continuous ridge vent is not practical.
- See also: Ridge Vent, Exhaust Vent, Power Vent
- Buckling
- Wavy, raised lines running across a shingle roof. It usually traces back to the deck or underlayment moving: swelling sheathing, wrinkled felt that got wet before shingling, or decking that was installed without spacing gaps.
- See also: Deck, Felt Underlayment
- Building Permit
- Also called: Roofing permit
- Written approval from the local building department to do the work, followed by one or more inspections. Most Michigan jurisdictions require a permit for a roof replacement. Requirements vary by township and city, so check with yours or ask the roofer who pulls it.
- See also: Final Inspection, Michigan Residential Code (MRC), How to hire a roofer in Michigan
- Built-Up Roofing (BUR)
- Also called: Tar and gravel roof
- A traditional low-slope system of alternating layers of roofing felt and hot or cold asphalt (or coal tar), usually finished with a layer of gravel. It is heavy and redundant, but it is labor-intensive and has largely given way to single-ply and modified bitumen systems.
- See also: Aggregate, Modified Bitumen, Flat roof systems
- Bundle
- The package shingles are sold in. Many common architectural shingles come three bundles to a square (100 square feet of coverage), but some heavier products take four or more, so check the wrapper rather than assume.
- See also: Square, Roofing calculators
- Butyl Tape
- A sticky, rubbery sealing tape used in metal roofing laps, flashings and some membrane details. It stays flexible for years and seals out water where two pieces of material overlap.
- See also: Standing Seam, Exposed-Fastener Metal Roof
- Cant Strip
- A triangular strip, often wood fiber or perlite, set in the 90-degree corner where a low-slope roof meets a wall. It softens the bend so the membrane or felt does not have to make a sharp fold that can crack.
- See also: Base Flashing, Built-Up Roofing (BUR)
- Cap Nail
- Also called: Plastic cap nail
- A roofing nail with a wide plastic or metal washer under the head, used to fasten underlayment. The wide head holds synthetic underlayment down in wind far better than a bare nail or staple.
- See also: Synthetic Underlayment, Underlayment
- Cap Sheet
- The top, weather-exposed ply of a modified bitumen or built-up roof, usually surfaced with mineral granules for protection from sunlight.
- See also: Base Sheet, Modified Bitumen
- Certificate of Insurance (COI)
- Also called: COI
- A one-page document from a contractor's insurance agent showing their general liability and workers' compensation coverage, limits and dates. Ask for it to be sent directly from the agent, and check that the named business matches your contract.
- See also: Workers' Compensation, How to hire a roofer in Michigan, 12 questions to ask a roofer
- Change Order
- A signed, written amendment to a roofing contract that changes the scope, price or schedule after work starts, for example extra decking or a code-required item that was not in the original bid. Get it in writing, with the price, before the extra work is done.
- See also: Allowance, Unit Price, How to read a roofing estimate
- Chimney Cricket
- Also called: Chimney saddle
- A small peaked roof built on the uphill side of a chimney to split water and snow around it instead of letting them pile against the back. The residential code requires one behind chimneys wider than 30 inches that do not sit on the ridge.
- See also: Cricket, Counterflashing, Flashing issues
- Class 4 Impact Rating
- The highest impact rating under the UL 2218 test, meaning a sample withstood a 2-inch steel ball dropped from 20 feet without cracking. Impact-rated shingles can resist hail better, and some insurers discount premiums for them. Class 4 does not mean hail-proof, and it is not a wind rating.
- See also: Impact-Resistant Shingle, Wind Rating, Hail damage
- Class A Fire Rating
- The highest fire-resistance classification for roof coverings under the UL 790 / ASTM E108 test, which measures how the roof resists fire from outside, such as embers. Most asphalt shingles, metal, slate and tile carry Class A ratings, sometimes only when installed over a specified underlayment.
- See also: Best roofing material for Michigan
- Closed-Cut Valley
- A valley where shingles from one slope run through the valley and shingles from the other slope are laid over them and cut in a straight line a couple of inches from the center. It is the most common asphalt valley style today.
- See also: Valley, Open Valley, Woven Valley
- Collar Tie
- A horizontal board that connects opposing rafters in the upper part of the attic. It helps hold the roof framing together against wind and uneven loads.
- See also: Rafter, Roof sagging
- Condensation
- Water that forms when warm, moist air hits a cold surface. In a roof, it shows up as damp sheathing, rusty nail tips, drips or mold in the attic, and it is usually a ventilation, air sealing or bathroom-fan venting problem rather than a roof leak.
- See also: Attic Frost, Vapor Retarder, Mold in the attic
- Construction Lien
- Also called: Mechanic's lien
- A claim against your property that an unpaid contractor, subcontractor or supplier can record under Michigan's Construction Lien Act, even if you paid your roofer in full. Sworn statements and lien waivers are how homeowners protect themselves.
- See also: Sworn Statement, Lien Waiver, Construction Lien Act
- Construction Lien Act
- Michigan's law governing construction liens (MCL 570.1101 and following). It sets out who can claim a lien, the sworn statement and waiver-of-lien process, and the homeowner payment affidavit defense. This is general information, not legal advice.
- See also: Sworn Statement, Lien Waiver, Homeowner Construction Lien Recovery Fund
- Cool Roof
- A roof surface designed to reflect more sunlight and give off absorbed heat, lowering roof temperature. It pays off most on flat commercial roofs with big cooling loads. In Michigan's heating-dominated climate the savings on a house are modest. The ENERGY STAR label for roof products ended in 2022.
- See also: Solar Reflectance, Energy-efficient roofing
- Coping
- Also called: Coping cap
- The metal (or stone) cap over the top of a parapet wall that seals the top and sheds water to both sides. Loose or poorly seamed coping is a common source of commercial roof leaks.
- See also: Parapet, Edge Metal
- Core Cut
- Also called: Core sample
- A small plug cut through a low-slope roof to see what is actually there: how many roofs, what insulation, whether it is wet, and what the deck is. It is patched immediately afterward and is the only sure way to decide between recover and tear-off.
- See also: Infrared Moisture Survey, Recover Board, Flat roof systems
- Counterflashing
- Also called: Cap flashing
- Metal flashing set into or fastened to a wall or chimney that laps down over the base or step flashing below it. The two pieces work together so the joint can move without opening a gap. On masonry it is typically set into a cut mortar joint or reglet.
- See also: Step Flashing, Reglet, Flashing repair
- Course
- A single horizontal row of shingles, slates or tiles running across the roof.
- See also: Exposure, Starter Strip
- Cover Board
- A thin, stiff board (gypsum, high-density polyiso or wood fiber) placed on top of the insulation under a low-slope membrane. It spreads out foot traffic and hail impacts and gives the membrane a smooth, stable surface.
- See also: Polyiso, Recover Board
- Crease
- Also called: Creased shingle
- A horizontal fold line across a shingle where wind lifted and bent it back. A creased shingle has lost strength and usually its seal, and it counts as wind damage even if it has settled back down.
- See also: Wind Damage, Sealant Strip
- Cricket
- On a low-slope roof, a small sloped build-up (usually tapered insulation) that diverts water around a curb or toward a drain instead of letting it pond. On a house it most often means the saddle behind a chimney.
- See also: Chimney Cricket, Tapered Insulation, Ponding Water
- Curb
- A raised frame on the roof that a skylight, rooftop unit, hatch or fan sits on, flashed on all four sides. Curbs lift the opening above the water line and are a frequent leak point on commercial roofs.
- See also: Base Flashing, Skylight repair
- Curling
- Also called: Cupping, clawing
- Shingle edges lifting up (cupping) or corners turning down (clawing) as a shingle ages, loses oils or is overheated by a poorly vented attic. Widespread curling is a classic end-of-life sign.
- See also: Roof aging signs, Ventilation problems
- Date of Loss
- The date the storm or event that caused the damage happened. Insurers use it to confirm the policy was in force and to check deadlines for reporting a claim, so note it and keep weather reports or photos.
- See also: Proof of Loss, What to do after storm damage
- Dead Valley
- A spot where two roof planes meet in a way that water and snow cannot drain out easily, such as behind a chimney or where a dormer wall meets a roof. Dead valleys collect debris and ice and need extra ice barrier and careful flashing.
- See also: Cricket, Ice Barrier
- Deck
- Also called: Roof deck, sheathing, decking
- The structural surface the roof is fastened to: plywood or OSB on most homes, older plank boards on many pre-1970 houses, and steel, concrete or wood on commercial buildings. Soft, rotted or delaminated decking has to be replaced before a new roof goes on.
- See also: OSB, Plank Decking, Roof sagging
- Deductible
- The portion of a covered loss you pay before insurance pays. Some policies use a flat dollar deductible and some use a percentage of the dwelling coverage for wind or hail. The deductible is subtracted from the claim payment. No Michigan statute specifically bans a contractor waiving it, but inflating a claim to cover it is insurance fraud.
- See also: Insurance Fraud, Insurance roof claims, Common roofing scams in Michigan
- Delamination
- Layers separating that should stay bonded: plies of plywood or OSB coming apart from moisture, laminated shingle layers separating, or a membrane peeling from insulation.
- See also: Deck, OSB
- Deposit
- Money paid up front, often to order materials. Terms are negotiated in the contract; a reasonable deposit tied to a clear schedule is normal, but paying most of the job before work starts gives you little leverage.
- See also: Sworn Statement, How to hire a roofer in Michigan, 12 questions to ask a roofer
- Depreciation
- The amount an insurer subtracts from replacement cost for age and wear. On a replacement cost policy much of it is usually recoverable after the work is finished. On an actual cash value policy it is not.
- See also: Recoverable Depreciation, Non-Recoverable Depreciation, Actual Cash Value (ACV)
- Detach and Reset (D&R)
- Also called: D&R, remove and reinstall (R&R)
- An estimate line for removing an item so roofing can be done, then putting it back: satellite dishes, solar panels, gutters, snow guards, antennas. In insurance estimates, R&R usually means remove and replace, while D&R means remove and put the same item back.
- See also: Line Item, Xactimate, How to read a roofing estimate
- Dimensional Shingle
- Another name for an architectural (laminated) shingle.
- See also: Architectural Shingle
- Dormer
- A structure that projects out of a sloped roof with its own small roof and a vertical wall, usually holding a window. Dormers add step flashing, valleys and small roof-to-wall joints, which is where many residential leaks start.
- See also: Step Flashing, Kick-Out Flashing
- Downspout
- Also called: Leader, conductor
- The vertical pipe that carries water from a gutter or scupper to the ground or a drain. Downspouts should discharge away from the foundation, not onto a lower roof without a splash guard.
- See also: Gutter Apron, Scupper
- Drip Edge
- An L- or T-shaped metal strip along the eaves and rakes that directs water off the roof edge and away from the fascia, and closes the gap between deck and fascia. The residential code requires drip edge at the eaves and rake edges of asphalt shingle roofs.
- See also: Gutter Apron, Rake, Eave
- Dry-In
- The point at which the deck is covered with underlayment and flashings so the building is protected from rain, even though the final roof covering is not on yet. A good crew only tears off what it can dry in the same day.
- See also: Underlayment, Tear-Off
- Eave
- The lower, horizontal edge of a roof slope that overhangs the wall, where water runs off into the gutter. The eave is where ice dams form, which is why ice barrier starts there.
- See also: Ice Barrier, Soffit, Fascia
- Edge Metal
- Also called: Gravel stop, roof edge
- The metal trim along the perimeter of a low-slope roof that holds the membrane edge down and finishes it. Because wind uplift starts at the edge, commercial edge metal is typically tested to the ANSI/SPRI ES-1 standard.
- See also: Coping, Uplift, Flat roof systems
- Elastomeric
- Rubber-like: able to stretch and recover. Elastomeric roof coatings (acrylic, silicone, urethane) and membranes flex with the roof as it heats, cools and moves without cracking.
- See also: Acrylic Roof Coating, Silicone Roof Coating
- EPDM
- Also called: Rubber roof
- Ethylene propylene diene monomer, a black synthetic rubber single-ply membrane for low-slope roofs. It is durable, flexible in cold and has a long track record, with seams joined by tape and adhesive rather than heat welding.
- See also: EPDM roofing, TPO, Thermoset vs. Thermoplastic
- Estimate
- Also called: Bid, proposal, quote
- A contractor's written price and scope for the job. A useful roofing estimate lists materials by product line, what is torn off, underlayment and ice barrier coverage, flashing, ventilation, decking pricing, cleanup, permit and warranty, so you can compare bids line by line.
- See also: Scope of Work, Line Item, How to read a roofing estimate
- Exhaust Vent
- A vent high on the roof, such as a ridge vent, box vent or gable vent, that lets warm, moist air leave the attic. It only works if there is matching intake low on the roof.
- See also: Intake Vent, Ventilation, Ridge Vent
- Expansion Joint
- A flexible joint in a roof, usually on larger commercial buildings, that lets separate sections move without tearing the membrane. It needs its own flashing and cover.
- See also: Flat roof systems
- Exposed Nail
- A nail head left uncovered by the next course or at ridge cap, often sealed with a dab of sealant. Exposed nails that are not sealed are a leak and rust point.
- See also: Nail Pop, Ridge Cap
- Exposed-Fastener Metal Roof
- Also called: Screw-down panel, ag panel, R-panel
- Metal panels fastened through the face with gasketed screws. They cost less than standing seam, but the rubber washers on thousands of screws age and need periodic checking or replacement, and the panels cannot move freely with temperature.
- See also: Standing Seam, Metal roofing, Metal roof cost
- Fascia
- The vertical trim board along the roof edge at the eaves, where gutters are usually attached. It is part of the house trim, not the roof itself, and it rots when water gets behind the gutter or drip edge.
- See also: Soffit, Drip Edge, Gutter Apron
- Felt Underlayment
- Also called: Tar paper, #15 felt, #30 felt
- Traditional underlayment made of paper or fiberglass saturated with asphalt, sold in lighter (#15) and heavier (#30) weights. It is still code-compliant, but most roofers now use synthetic underlayment, which is lighter, stronger and less prone to wrinkling.
- See also: Synthetic Underlayment, Underlayment
- Field
- The main, open area of a roof slope, as opposed to edges, ridges, valleys and penetrations. Hail and wear are often judged on the field.
- See also: Test Square
- Final Inspection
- The building department's inspection after the roof is complete to close the permit. Ask your roofer for proof it passed; an open permit can become a problem when you sell.
- See also: Building Permit, Roofs when buying or selling a home
- Fishmouth
- An open wrinkle or gap at the edge of a membrane seam or lap, shaped like an open mouth. Water and wind get into it, so it is a common repair item on older low-slope roofs.
- See also: Seam, Flat roof repair
- Flashing
- Thin metal or membrane pieces that seal the joints where the roof meets something else: walls, chimneys, skylights, vents, valleys and edges. Most roof leaks are flashing failures rather than failures in the open field of shingles.
- See also: Step Flashing, Counterflashing, Flashing issues, Flashing repair
- Flat Roof
- The everyday name for a low-slope roof. Almost no roof is truly flat: a properly designed one has a slight slope, typically at least 1/4 inch per foot, to move water to drains or edges.
- See also: Low-Slope Roof, Flat roof systems, Flat roof repair
- Fleece-Back Membrane
- A single-ply membrane (TPO, PVC or EPDM) with a felt-like fleece layer bonded to the back. The fleece improves adhesion and lets the membrane go over rougher substrates, which is common on recover projects.
- See also: Fully Adhered, TPO
- FM Approval
- Also called: FM rating
- Testing and approval of commercial roof assemblies by FM Approvals, part of the insurer FM Global. A rating like 1-90 means the assembly met Class 1 fire requirements and resisted 90 pounds per square foot of wind uplift. Some commercial insurers require FM-approved assemblies.
- See also: Uplift, Commercial roofing
- Freeze-Thaw Cycle
- One swing of temperature below and back above freezing. West Michigan sees many of them each winter, and each one lets water get into cracks and gaps, freeze, expand and pry them wider. It is a big reason flashing sealants, masonry and marginal details wear faster here.
- See also: Ice Dam, Lake-Effect Snow, Best roofing material for Michigan
- Fully Adhered
- A low-slope membrane glued down across its whole surface to the insulation or cover board below, rather than fastened only at seams or held with ballast. It resists wind flutter and is quieter, at a higher installed cost.
- See also: Mechanically Attached, Ballast
- Gable
- The triangular wall section at the end of a pitched roof, between the two sloping edges. A gable roof has two slopes that meet at a ridge.
- See also: Rake, Hip Roof, Gable Vent
- Gable Vent
- A louvered vent in the gable wall near the peak. It can work as exhaust on simple attics, but mixing gable vents with a ridge vent can short-circuit the airflow so the ridge pulls from the gable instead of the soffits.
- See also: Ridge Vent, Ventilation, Ventilation problems
- Galvalume
- Steel coated with an aluminum-zinc alloy for corrosion resistance, widely used for metal roof panels. Galvanized steel uses a zinc-only coating. Both are usually painted for color and extra protection.
- See also: Metal roofing, Standing Seam
- Gambrel Roof
- A barn-style roof with two slopes on each side: a shallow upper slope and a steep lower one. The steep lower slopes and the transition between them need careful flashing and fastening.
- See also: Mansard Roof
- Granule Loss
- Shingles shedding their protective granules, showing as bald or dark patches and granules piling in the gutters and at downspouts. It comes from age, hail, foot traffic or manufacturing issues. Once the asphalt is exposed to sun, it ages quickly.
- See also: Granule loss, Hail Bruise, Roof aging signs
- Granules
- The ceramic-coated crushed rock embedded in the top of asphalt shingles. They protect the asphalt from UV light, add color and add fire resistance. Some granules come loose on a new roof, which is normal.
- See also: Granule Loss, Granule loss
- Gutter Apron
- A flashing strip at the eaves that tucks under the shingles and extends down into the gutter so water cannot run behind it onto the fascia. It overlaps with drip edge in purpose, and many roofers install one or the other at the eaves depending on the gutter setup.
- See also: Drip Edge, Fascia
- Gutter Guard
- A screen, mesh or cover over a gutter meant to keep leaves out. Guards reduce cleaning but do not eliminate it, and in snow country some types can hold ice at the eaves. Install them so they do not lift the first course of shingles.
- See also: Ice Dam
- Haag Certification
- Also called: Haag certified inspector
- A credential from Haag, an engineering and training firm, for inspecting roofs for hail and wind damage using consistent, documented methods. Many insurance adjusters train on the same methods, which makes it useful common ground on a claim. It is a training credential, not a license.
- See also: Test Square, Hail Bruise, Hail damage
- Hail Bruise
- A soft spot on a shingle where hail cracked the fiberglass mat underneath without necessarily knocking granules off. It feels spongy under light thumb pressure, and over time granules fall away there and the shingle can crack or leak. A bruise, not a scuff, is what distinguishes functional hail damage.
- See also: Hail damage, Hail damage repair, Test Square
- Hail Damage
- Damage from hailstones: bruised or cracked shingles, dented metal, split membranes and damaged soft metals like vents and gutters. Functional damage that shortens roof life is what insurers generally cover, not cosmetic dents alone (check your policy).
- See also: Hail Bruise, Hail damage, Hail damage repair
- Hand Sealing
- Applying dabs of roofing adhesive under shingle tabs by hand. Manufacturers call for it in certain conditions, such as very steep slopes or cold-weather installs, where the factory sealant strip may not bond on its own before winter wind.
- See also: Sealant Strip, Blow-Off
- Headlap
- How far each course overlaps the course two rows below it. Headlap is what keeps water that runs through the joints of one course from reaching the deck.
- See also: Exposure, Course
- Heat Cable
- Also called: Heat tape, roof de-icing cable
- Electric cable laid in a zigzag along eaves and in gutters to melt channels through ice. It treats the symptom of ice dams, not the cause, and should be installed per the manufacturer and on a properly protected circuit.
- See also: Ice Dam, Ice dams, Roof snow removal
- Heat-Welded Seam
- A seam in a thermoplastic membrane such as TPO or PVC made by melting the two overlapping sheets together with hot air. A properly welded seam becomes one continuous sheet and is checked with a seam probe.
- See also: TPO, PVC Membrane, Thermoset vs. Thermoplastic
- High Nailing
- Driving shingle nails above the manufacturer's nail line. High-nailed shingles miss the overlap of the shingle below, have less holding power and are a leading cause of blow-offs. It is usually a workmanship issue and can affect warranty coverage.
- See also: Nail Line, Blow-Off, Wind damage
- Hip
- The sloped external ridge where two roof slopes meet at an outside corner. Hips are capped with hip and ridge shingles or metal trim.
- See also: Hip Roof, Ridge Cap
- Hip Roof
- A roof that slopes down on all four sides to the eaves, with no vertical gable ends. Hip roofs handle wind well but have less room for exhaust vents and produce more cut waste than gables.
- See also: Gable, Waste Factor
- Home Solicitation Sale
- Also called: Door-to-door sale, 3-day right to cancel
- Under Michigan's Home Solicitation Sales Act (MCL 445.111 and following), a sale made at your home generally lets you cancel until midnight of the third business day after signing, with limited exceptions for real emergencies. General information, not legal advice.
- See also: Storm Chaser, Common roofing scams in Michigan
- Homeowner Construction Lien Recovery Fund
- A former Michigan fund that protected homeowners who paid a contractor who then failed to pay subs or suppliers. It was abolished in 2010. Today homeowners rely on sworn statements, lien waivers and the payment affidavit defense in the Construction Lien Act. General information, not legal advice.
- See also: Construction Lien Act, Sworn Statement, Lien Waiver
- Ice and Water Shield
- Also called: Self-adhered membrane, peel-and-stick, ice barrier
- A self-adhering rubberized asphalt membrane that sticks directly to the deck and seals around nails. It is used at eaves, valleys and around penetrations where water can back up or pond. The name began as a trademark but is now used generically for any product of this type.
- See also: Ice Barrier, Underlayment, Ice dams
- Ice Barrier
- The code term for the membrane required along the eaves in areas prone to ice dams. Under the residential code it must run from the eave to at least 24 inches inside the exterior wall line of the house, which on deep overhangs or low pitches can mean two or more rows.
- See also: Ice and Water Shield, Ice Dam, Ice dams
- Ice Dam
- A ridge of ice at the roof edge that traps meltwater behind it. Heat escaping from the house melts snow higher on the roof, the water refreezes over the colder eaves, and the pond that builds up can back under shingles and into walls and ceilings. The long-term fix is air sealing, insulation and ventilation.
- See also: Ice dams, Ice Barrier, Attic Air Bypass, Roof snow removal
- Icicles
- Icicles along a gutter are not always a problem, but large, thick ones, especially paired with ice building up on the roof edge, usually mean heat loss is melting snow and an ice dam is forming.
- See also: Ice Dam
- Impact-Resistant Shingle
- A shingle, usually made with a polymer-modified asphalt, that has earned a UL 2218 impact rating, most often Class 4. It tends to hold up better to hail, and some insurers offer a discount. Ask your agent whether yours does before you pay a premium for it.
- See also: Class 4 Impact Rating, Hail damage, Best roofing material for Michigan
- Infrared Moisture Survey
- Also called: IR roof scan, thermal scan
- A thermal camera scan of a low-slope roof, usually done after sunset, that finds wet insulation because wet areas hold heat longer than dry ones. Suspect areas are confirmed with core cuts or moisture meters before deciding how much to replace.
- See also: Core Cut, Wet Insulation, Commercial roofing
- Insurance Fraud
- Knowingly presenting false or inflated information to an insurer, for example an estimate padded to cover your deductible. In Michigan, fraudulent insurance acts are defined in the Insurance Code (MCL 500.4503) and carry serious penalties for everyone involved. General information, not legal advice.
- See also: Deductible, Common roofing scams in Michigan
- Intake Vent
- A vent low on the roof, usually in the soffits or at the roof edge, that lets outside air into the attic. Intake air pushes warm, moist air out the exhaust vents. Most attic ventilation problems are really a shortage of intake.
- See also: Soffit Vent, Exhaust Vent, Baffle
- Kick-Out Flashing
- Also called: Diverter flashing
- A small angled flashing at the bottom of a roof-to-wall joint that kicks water out into the gutter instead of letting it run down the wall. Missing kick-outs are a common cause of hidden rot in walls below where a roof ends against siding.
- See also: Step Flashing, Flashing issues
- Lake-Effect Snow
- Snow produced when cold air crosses the relatively warm waters of Lake Michigan and dumps heavy, often localized snowfall on the downwind shore. It is why West Michigan gets far more snow than cities at the same latitude inland, and why ice barrier, ventilation and snow load matter so much here.
- See also: Ice Dam, Snow Load, Roof snow removal
- Laminated Shingle
- Another name for an architectural shingle, referring to the layers glued together.
- See also: Architectural Shingle
- LARA
- The Michigan Department of Licensing and Regulatory Affairs, which licenses residential builders and maintenance and alteration contractors. You can look up whether a roofer's license is active on LARA's website.
- See also: Residential Builder License, Maintenance and Alteration Contractor License, How to hire a roofer in Michigan
- Layover
- Another name for a roof-over or re-cover: new shingles installed over the existing ones without a tear-off.
- See also: Roof-Over
- Lien Waiver
- Also called: Waiver of lien
- A signed document in which a contractor, subcontractor or supplier gives up lien rights for amounts paid. Michigan's statutory forms come as full or partial, and conditional (effective once payment clears) or unconditional. Collect them from the roofer and any subs or suppliers listed on the sworn statement. General information, not legal advice.
- See also: Sworn Statement, Construction Lien Act, How to hire a roofer in Michigan
- Line Item
- One priced entry on an estimate, such as tear-off per square, ice barrier per square, drip edge per linear foot, or a pipe boot each. Line items make it possible to compare bids and to see what an insurance estimate did or did not include.
- See also: Estimate, Xactimate, How to read a roofing estimate
- Linear Foot
- Also called: LF
- A straight-line measurement in feet, used for roof edges and trim: drip edge, ridge cap, valleys, step flashing and starter strip are all measured and priced per linear foot rather than per square.
- See also: Square, Aerial Measurement Report
- Liquid-Applied Membrane
- A roof or flashing membrane applied as a liquid, often with reinforcing fabric, that cures into a seamless skin. Useful around odd-shaped penetrations and in restoration systems.
- See also: Roof Coating, Commercial roof coatings
- Low-Slope Roof
- A roof with a slope of 3:12 or less, the typical commercial flat roof and many porch, garage and addition roofs. Shingles are not designed for these slopes; they need a continuous membrane such as TPO, EPDM, PVC or modified bitumen.
- See also: Flat Roof, Steep-Slope Roof, Flat roof systems
- Magnet Sweep
- Rolling a magnetic sweeper across the yard and driveway after a roof job to pick up nails. Ask whether it is included, and how often the crew does it.
- See also: Punch List
- Maintenance and Alteration Contractor License
- Also called: M&A license
- A Michigan license issued by LARA for specific trades, including roofing, as an alternative to a full residential builder license. Roofing work on homes requires one of the two. Ask for the license number and check it online.
- See also: Residential Builder License, LARA, How to hire a roofer in Michigan
- Mansard Roof
- A roof with steep, nearly vertical lower slopes on all sides and a shallow or flat upper section. The steep sections are often shingled like walls, and the flat top needs a membrane.
- See also: Gambrel Roof, Low-Slope Roof
- Manufacturer Warranty
- The shingle or membrane maker's warranty covering defects in the material, and, on enhanced system warranties, some installation labor. Coverage usually depends on correct installation, sometimes on using the maker's matching components, and sometimes on registration.
- See also: Workmanship Warranty, Prorated Warranty, Roofing warranties
- Mat
- The reinforcing core of an asphalt shingle, today almost always fiberglass (older shingles used organic felt). Hail that fractures the mat creates a bruise even if the surface looks intact.
- See also: Hail Bruise, Asphalt Shingle
- Matching
- The question of whether an insurer must pay to replace undamaged areas so repairs match in color and style, for example when a discontinued shingle cannot be matched. Whether you get it depends on your policy language and state rules, so read the policy and ask your adjuster. General information, not legal advice.
- See also: Supplement, Insurance FAQ
- Mechanically Attached
- A low-slope membrane held down with screws and plates along the seams, which are then covered by the next sheet. It is fast and economical, and fastener spacing is engineered to the wind zone and building height.
- See also: Fully Adhered, Ballast, TPO
- Metal Roofing
- Steel, aluminum, copper or zinc roofing in panel or shingle form. Common residential types are standing seam, exposed-fastener panels and stamped or stone-coated metal shingles. Metal sheds snow quickly, which means snow guards over walkways and entries.
- See also: Metal roofing, Standing Seam, Snow Guard, Metal roof cost
- Michigan DIFS
- The Michigan Department of Insurance and Financial Services, the state regulator of insurance companies and agents. If you believe your insurer is mishandling a claim, you can file a complaint with DIFS.
- See also: Appraisal Clause, Insurance roof claims
- Michigan Residential Code (MRC)
- Michigan's building code for one- and two-family homes, based on the International Residential Code. As of 2026 Michigan is enforcing the 2015 edition after a court order in July 2025 blocked adoption of the 2021 update. Chapter 9 covers roof assemblies and reroofing.
- See also: Building Permit, Roof-Over
- Mitigation
- Also called: Duty to mitigate
- The policyholder's obligation, found in most homeowners policies, to take reasonable steps to prevent further damage after a loss, such as tarping a hole. Keep receipts and photos; reasonable emergency repairs are typically part of the claim.
- See also: Tarping, Emergency roof repair, What to do after storm damage
- Modified Bitumen
- Also called: Mod-bit, SBS, APP, torch-down
- Asphalt roofing modified with rubbery (SBS) or plastic (APP) polymers and made into rolls, used on low-slope roofs in two or more plies. It is installed by torch, hot asphalt, cold adhesive or self-adhered sheets, and is common on small commercial and residential flat roofs.
- See also: Base Sheet, Cap Sheet, Torch-Down, Flat roof systems
- Mortgagee
- Also called: Loss payee
- Your mortgage lender, which is usually named on your homeowners policy. Insurance checks for roof claims are often made out to both you and the lender, and the lender may hold the funds and release them as work is done.
- See also: Insurance roof claims, Insurance FAQ
- Moss
- Green growth that takes hold on shaded, damp roof areas and holds moisture against shingles or shakes. It can lift shingles and speed up decay. Remove it gently and fix the shade and debris conditions that let it grow.
- See also: Algae Streaks, Roof maintenance checklist
- Nail Line
- The marked strip on a shingle where nails belong, placed so each nail catches both the shingle and the top of the one beneath. Nailing on the line is one of the details manufacturers inspect for warranty.
- See also: High Nailing, Nailing Pattern
- Nail Pop
- A nail that has backed out and pushed up the shingle above it, often from deck movement or a nail that missed the framing or was driven at an angle. Popped nails can wear a hole in the shingle above and let water in.
- See also: Deck, Leaking roof
- Nailing Pattern
- How many nails go into each shingle and where. Standard patterns use four nails per shingle, while high-wind patterns and steeper slopes call for six. The manufacturer's instructions govern.
- See also: Nail Line, Wind Rating
- NDL Warranty
- Also called: No-dollar-limit warranty
- A commercial roof warranty from the manufacturer that covers repair of leaks caused by materials or workmanship with no cap on the dollar amount, for a set term. It normally requires an approved installer, a manufacturer inspection at completion and routine maintenance.
- See also: Roofing warranties, Commercial roofing
- Net Free Area (NFA)
- Also called: NFA
- The actual open area a vent lets air through, after subtracting screens and louvers, listed by the vent maker in square inches. Attic ventilation is sized by net free area: the residential code's baseline is 1 square foot of NFA per 150 square feet of attic floor, which may drop to 1 per 300 when specific conditions are met.
- See also: Ventilation, Ventilation problems, Roofing calculators
- Non-Recoverable Depreciation
- Depreciation an insurer subtracts and will not pay back, even after the work is done. It applies on actual cash value coverage and to some items on otherwise replacement cost policies.
- See also: Recoverable Depreciation, Actual Cash Value (ACV)
- Notice of Furnishing
- A notice that subcontractors and suppliers on a Michigan project may need to send the property owner to protect their lien rights. If you receive one, it tells you who else expects to be paid, and those names should appear on the contractor's sworn statement.
- See also: Sworn Statement, Construction Lien Act
- NRCA
- The National Roofing Contractors Association, a US trade association that publishes widely used technical guidance, including The NRCA Roofing Manual.
- Off-Ridge Vent
- A short, slotted exhaust vent installed near but below the ridge, used where a continuous ridge vent will not fit, such as on short ridges or hip roofs.
- See also: Ridge Vent, Box Vent
- Open Valley
- A valley lined with metal (or a membrane) that stays exposed, with shingles on both sides cut back from the center. Open metal valleys handle heavy water flow and debris well.
- See also: Valley, Closed-Cut Valley
- Ordinance or Law Coverage
- Also called: Code upgrade coverage
- Insurance coverage for the extra cost of meeting current building codes when damaged property is repaired, for example code-required ice barrier or drip edge the old roof never had. Many policies include a limited amount, and some require an endorsement. Check your declarations page.
- See also: Michigan Residential Code (MRC), Insurance roof claims
- OSB
- Also called: Oriented strand board
- A structural panel made of wood strands pressed and glued in layers, the most common roof sheathing on newer homes. It performs well when kept dry but swells at the edges and loses strength when it stays wet.
- See also: Deck, Plank Decking
- Overhang
- The part of the roof that extends past the exterior walls at eaves and rakes. Deep overhangs keep water off walls but push the eave further from the warm wall line, which affects how much ice barrier the code requires.
- See also: Ice Barrier, Soffit
- Overhead and Profit (O&P)
- Also called: O&P, 10 and 10
- A charge on an estimate for a contractor's business overhead and profit, often shown as 10 percent plus 10 percent on insurance estimates. Insurers generally include it when a general contractor is reasonably needed to coordinate several trades, but it is not automatic on every claim.
- See also: Xactimate, Supplement, How to read a roofing estimate
- Parapet
- A low wall that extends above the roof line at the edge of a flat roof. Parapets need base flashing, counterflashing and coping, and they can trap water and snow, so drainage has to go through scuppers or drains.
- See also: Coping, Scupper, Base Flashing
- Payment Affidavit
- Under Michigan's Construction Lien Act, a sworn statement a homeowner can use to show they paid their contractor in full for the work, which can defeat a lien claim from an unpaid sub or supplier (MCL 570.1118a). Keep proof of every payment. General information, not legal advice.
- See also: Construction Lien Act, Sworn Statement
- Penetration
- Anything that pokes through the roof: plumbing vents, exhaust fans, chimneys, skylights, satellite mounts, solar standoffs. Each one needs its own flashing and is a potential leak point.
- See also: Pipe Boot, Pitch Pan, Leaking roof
- Pipe Boot
- Also called: Plumbing vent flashing, vent boot
- A flashing that seals around a plumbing vent pipe, usually a metal or plastic base with a rubber collar. The rubber collars crack from sunlight years before the shingles wear out, making them one of the most common residential leak sources.
- See also: Penetration, Leaking roof
- Pitch
- Also called: Roof pitch, slope
- How steep a roof is, stated as inches of rise per 12 inches of horizontal run, such as 4/12 or 8/12. Strictly speaking, pitch is rise over the full span and slope is rise over run, but roofers use the terms interchangeably.
- See also: Rise and Run, Slope Factor, Roofing calculators
- Pitch Pan
- Also called: Pitch pocket
- A metal collar around an oddly shaped penetration on a flat roof, such as a steel support, filled with sealant. It needs periodic topping off as the filler shrinks. Pre-formed boots are a longer-lasting option where they fit.
- See also: Penetration, Flat roof repair
- Plank Decking
- Also called: Board sheathing, skip sheathing
- Solid wood boards used as roof deck on many older homes. When the gaps between boards are too wide for shingle nails to hold, the deck is typically overlaid with plywood or OSB during a replacement.
- See also: Deck, OSB
- Polyiso
- Also called: Polyisocyanurate, ISO board
- The most common rigid foam insulation board on commercial low-slope roofs, with foil or fiberglass facers. It offers high insulating value per inch, although that value drops somewhat in very cold weather.
- See also: Tapered Insulation, Cover Board, R-Value
- Ponding Water
- Water that remains on a low-slope roof long after rain; the industry commonly treats water still standing 48 hours after a storm as ponding. It points to poor slope or clogged drains, adds weight and shortens membrane and coating life.
- See also: Tapered Insulation, Cricket, Flat roof repair
- Power Vent
- Also called: Powered attic ventilator, attic fan
- An electric or solar fan that pulls air out of the attic. If there is not enough intake, it can pull conditioned air and moisture up from the house, and it should not be combined with a ridge vent on the same attic.
- See also: Ridge Vent, Intake Vent, Ventilation problems
- Proof of Loss
- A sworn form some insurers require that states the amount you are claiming. Policies set deadlines for it, so read yours and ask the insurer for the form in writing if they want one.
- See also: Date of Loss, Insurance FAQ
- Prorated Warranty
- A warranty whose coverage shrinks over time, so a claim in year 18 pays a fraction of what it would in year 2. Most manufacturer shingle warranties have a non-prorated early period, then prorate. Read what the period covers: material only, or labor too.
- See also: Manufacturer Warranty, Roofing warranties
- Public Adjuster
- An adjuster you hire, licensed by the state, to prepare and negotiate your insurance claim for a percentage of the settlement. In Michigan public adjusters are licensed through DIFS. Roofing contractors are not public adjusters and should not negotiate your claim for you.
- See also: Adjuster, Michigan DIFS
- Punch List
- The list of small items still to finish or correct before a job is complete, such as a missed nail, a dented gutter or trim touch-up. Walk the property with the roofer and agree on the list before the final payment.
- See also: Final Inspection, Lien Waiver
- PVC Membrane
- A thermoplastic single-ply membrane made from polyvinyl chloride, heat welded at the seams. It resists grease and many chemicals, making it a common choice for restaurants and roofs with kitchen exhaust.
- See also: TPO, Heat-Welded Seam, Flat roof systems
- R-Value
- A measure of how well insulation resists heat flow; higher is better. On low-slope roofs the insulation is above the deck, so a reroof is often when insulation is upgraded to meet the current energy code.
- See also: Polyiso, Tapered Insulation
- Rafter
- One of the sloped framing members that support the roof deck. Many newer homes use factory-built trusses instead of site-framed rafters.
- See also: Truss, Collar Tie
- Rake
- Also called: Rake edge
- The sloped edge of a roof at a gable end, running from eave to ridge. Rakes get drip edge and are high wind-uplift zones.
- See also: Gable, Drip Edge, Eave
- Recover Board
- A thin board installed over an existing low-slope roof before a new membrane goes on in a recover project, to give a clean, flat, compatible surface. Recovering is only appropriate when the existing insulation is dry and the code layer limits allow it.
- See also: Core Cut, Roof-Over
- Recoverable Depreciation
- Depreciation an insurer holds back at first on a replacement cost policy and pays after you complete the work and send proof, such as a final invoice. Policies often set a time limit for claiming it, so ask your adjuster what the deadline is.
- See also: Replacement Cost Value (RCV), Depreciation, Insurance roof claims
- Reglet
- A groove cut into masonry, or a metal receiver set into a wall, that holds the top edge of counterflashing so water cannot run behind it.
- See also: Counterflashing, Termination Bar
- Reinspection
- A second visit by the adjuster or a different adjuster, often requested when the roofer's findings differ from the first inspection. Being present with your own documentation, photos and test squares helps.
- See also: Adjuster, Supplement
- Release Tape
- The thin plastic strip on the back of each shingle that keeps bundled shingles from sticking to each other's sealant. It does not need to be removed during installation.
- See also: Sealant Strip
- Replacement Cost Value (RCV)
- Also called: RCV
- The cost to replace damaged property with new material of like kind and quality at today's prices, without subtracting depreciation. On a typical RCV policy the insurer pays the ACV amount first, then the held-back depreciation after the work is done.
- See also: Actual Cash Value (ACV), Recoverable Depreciation, Insurance roof claims
- Residential Builder License
- A Michigan license issued by LARA that allows a contractor to do residential construction, including roofing. Michigan's residential builder license numbers can be verified online.
- See also: Maintenance and Alteration Contractor License, LARA, How to hire a roofer in Michigan
- Restoration
- Also called: Roof restoration, recoat
- Extending the life of an aging but sound low-slope roof by cleaning, repairing and applying a coating system instead of replacing it. It works only when the roof and insulation are mostly dry, which is why a moisture survey comes first.
- See also: Roof Coating, Infrared Moisture Survey, Commercial roof coatings
- Retainage
- A percentage of each payment held back until the job is complete, common on commercial projects, to ensure punch list items and closeout paperwork get done.
- See also: Punch List, Commercial roofing
- Ridge Cap
- Also called: Hip and ridge shingles
- Special shingles or trim that cover the ridge and hips. Using pre-made ridge cap rather than shingles cut from three-tabs is what most manufacturers specify for warranty coverage and wind performance.
- See also: Ridge, Hip
- Ridge Vent
- A continuous exhaust vent along the ridge, with a slot cut in the deck below and a low-profile cover shingled over. Paired with soffit intake, it gives even airflow across the attic.
- See also: Soffit Vent, Ventilation, Ventilation problems
- Rise and Run
- The two measurements that define slope: rise is the vertical change and run is the horizontal distance. A roof that rises 6 inches over a 12-inch run is a 6/12 roof.
- See also: Pitch, Slope Factor, Roofing calculators
- Roll Roofing
- Also called: Mineral-surfaced roll roofing
- Asphalt roofing in rolls with a granule surface, used on low-slope sheds, porches and outbuildings. It is inexpensive and short-lived compared with shingles or a real low-slope membrane.
- See also: Low-Slope Roof, Modified Bitumen
- Roof Cement
- Also called: Flashing cement, plastic cement
- A thick asphalt-based mastic used to seal small details and set flashing. It is a supplement to proper flashing, not a substitute. A roof held together with cement usually means flashing that should have been replaced.
- See also: Flashing, Flashing repair
- Roof Coating
- A fluid-applied layer (acrylic, silicone, urethane or asphalt-based) that renews the surface of an existing low-slope roof and can add reflectivity. Coatings do not fix wet insulation or failing structure, and they must be compatible with the membrane underneath.
- See also: Restoration, Silicone Roof Coating, Commercial roof coatings
- Roof Drain
- A drain set into a low-slope roof that carries water down through the building to storm lines. Drains need clear strainer baskets; overflow drains or scuppers are a backup if the main drains clog.
- See also: Scupper, Ponding Water, Flat roof repair
- Roof Jack
- Also called: Toe board bracket, roof bracket
- A metal bracket nailed to the roof that holds a board crews can stand on. Roof jacks are part of the fall protection and staging on steeper roofs.
- See also: Steep Charge
- Roof Plane
- Also called: Facet
- One flat, continuous surface of a roof. A simple gable has two planes; a cut-up roof may have fifteen or more. Each plane is measured for area and pitch separately.
- See also: Aerial Measurement Report, Waste Factor
- Roof Surface Payment Schedule
- A policy provision or endorsement that pays for roof damage on a schedule based on the roof's age and material, rather than full replacement cost. It can sharply reduce what an older roof claim pays. Look for it on your declarations page before a storm.
- See also: Actual Cash Value (ACV), Insurance FAQ
- Roof-Over
- Also called: Re-cover, layover, shingle-over
- Installing a new roof over the existing one without tearing off. The Michigan Residential Code (R908.3.1.1) does not allow it when there are already two layers, when the existing roof or deck is water-soaked or deteriorated, or over wood shake, slate, clay or cement tile. Even where legal, it hides deck problems and can limit warranty options.
- See also: Tear-Off, Tear-off and replace, Repair vs. replace
- Rot
- Decay of wood decking, fascia or framing caused by fungi that need sustained moisture. Rot is a symptom; the cause is usually a leak, poor ventilation or condensation that has to be fixed along with the wood.
- See also: Deck, Leaking roof, Roof sagging
- Rubber Roof
- The everyday name for EPDM, and sometimes loosely for any single-ply membrane.
- See also: EPDM
- Scope of Work
- Also called: Scope
- The written description of exactly what will be done: what is removed, what is installed, and which details (flashing, ventilation, decking, cleanup) are included. In insurance, the scope of loss is the adjuster's list of what was damaged and will be paid.
- See also: Estimate, Line Item, How to read a roofing estimate
- Scupper
- An opening through a parapet wall that lets water drain off a flat roof, usually into a collector box and downspout. Overflow scuppers set higher on the wall act as a backup if the main drains clog.
- See also: Parapet, Roof Drain
- Sealant Strip
- Also called: Self-seal strip
- A line of heat-activated adhesive on each shingle that bonds it to the course below once the sun warms it. Shingles installed late in the Michigan season may not seal until spring, which is why some installs call for hand sealing.
- See also: Hand Sealing, Blow-Off, Wind damage
- Seam
- The joint where two sheets of membrane or metal overlap. On single-ply roofs seams are heat welded or taped, and seam failure is one of the most common commercial leak sources.
- See also: Heat-Welded Seam, Fishmouth
- Shake
- A wood roofing unit split from a block, usually cedar, so it has a rough, textured face and is thicker than a sawn shingle. Cedar shingles, by contrast, are sawn smooth on both sides.
- See also: Cedar shake, Wood Shingle
- Shed Roof
- A single-plane roof sloping in one direction, common on additions, porches and modern designs. Low-pitch shed roofs often need a membrane rather than shingles.
- See also: Low-Slope Roof, Pitch
- Shingle
- An individual overlapping roof unit, made of asphalt, wood, slate, metal, or composite. Shingle roofs shed water rather than being waterproof, so they depend on slope and overlap.
- See also: Asphalt Shingle, Water-Shedding Roof
- Silicone Roof Coating
- A fluid-applied coating for low-slope roofs made from silicone. It holds up well to standing water and UV and is often applied in one thick coat. Future coats generally have to be silicone as well, because most other materials will not stick to it.
- See also: Silicone roof coating, Acrylic Roof Coating, Commercial roof coatings
- Skylight
- A window in the roof, either curb-mounted or deck-mounted. Skylights usually need their own flashing kit and are a frequent leak source as seals and flashing age. Replacing an older skylight during a reroof is often the practical choice.
- See also: Skylight repair, Curb
- Slate
- Natural stone split into thin roofing tiles. A good slate roof can last many decades, but it is heavy, needs a skilled installer, and should not be walked on carelessly. Repairs use slate hooks or copper nails and matching stone.
- See also: Slate roofing, Roof lifespan comparison
- Slope Factor
- Also called: Pitch multiplier
- The number you multiply a roof's flat footprint by to get the actual sloped area. For example, about 1.054 for a 4/12, 1.118 for a 6/12, 1.202 for an 8/12 and 1.414 for a 12/12.
- See also: Pitch, Square, Roofing calculators
- Snow Guard
- Brackets or rails fastened to a roof, most often metal, that hold snow in place so it melts off gradually instead of sliding off in one dangerous sheet onto walkways, decks or lower roofs.
- See also: Metal Roofing, Roof snow removal
- Snow Load
- The weight of snow a roof is designed to carry, set by local code from ground snow load data. Wet, drifted lake-effect snow can weigh far more than fresh powder, and drifts pile against walls, parapets and lower roofs.
- See also: Lake-Effect Snow, Roof snow removal, Roof sagging
- Soffit
- The underside of the roof overhang, between the fascia and the house wall. Vented soffits are the main intake for attic ventilation.
- See also: Fascia, Soffit Vent
- Soffit Vent
- A vent in the soffit that lets outside air into the attic. Continuous or individual soffit vents only work if insulation is not blocking them from above.
- See also: Baffle, Intake Vent, Ventilation problems
- Solar Reflectance
- Also called: Reflectivity, SRI
- The fraction of sunlight a roof surface reflects. Solar Reflectance Index (SRI) combines reflectance with how well the surface sheds heat. White membranes and coatings score high; dark shingles score low.
- See also: Cool Roof, Energy-efficient roofing
- Spray Polyurethane Foam (SPF)
- Also called: SPF, spray foam roof
- A low-slope roof system in which liquid foam is sprayed on, expands into a seamless insulating layer, and is then protected with a coating. It must be recoated periodically to protect the foam from sunlight.
- See also: Roof Coating, Flat roof systems
- Square
- The roofing unit of area: 100 square feet of roof surface. A 25-square roof has about 2,500 square feet of surface. Materials and labor are usually priced per square.
- See also: Waste Factor, Cost per square foot, Roofing calculators
- Standing Seam
- A metal roof made of long vertical panels whose edges are joined in raised seams, with concealed clips holding the panels so they can expand and contract. No fasteners are exposed to the weather in the panel field.
- See also: Metal roofing, Exposed-Fastener Metal Roof, Metal roof cost
- Starter Strip
- The first course installed along the eaves and often the rakes, with its sealant positioned so the first row of shingles is glued down at the edge. Without it, the first course is the one wind lifts first.
- See also: Course, Blow-Off
- Steep Charge
- Also called: Steep and high roof charges
- Extra labor charged on steep or tall roofs because crews need safety equipment and work more slowly. Insurance estimating typically adds steep charges starting around 7/12 and high-roof charges for roofs two or more stories up.
- See also: Xactimate, Cost per square foot
- Steep-Slope Roof
- A roof steeper than 3:12, where water-shedding coverings such as shingles, slate, tile and metal panels are used. Asphalt shingles may be installed down to 2:12 with extra underlayment.
- See also: Low-Slope Roof, Pitch
- Step Flashing
- Individual L-shaped metal pieces woven in with each course of shingles where a roof slope runs alongside a wall or chimney. Each piece overlaps the one below like the shingles do. Reusing old, rusted step flashing is a common shortcut to ask about.
- See also: Counterflashing, Kick-Out Flashing, Flashing issues
- Stone-Coated Steel
- Steel roofing panels shaped like shingles, shakes or tile and coated with granules bonded in acrylic. They combine metal's durability with a traditional look.
- See also: Metal roofing, Metal Roofing
- Storm Chaser
- A contractor who follows hail and wind storms from state to state, canvasses door to door, and leaves town after the work, which can make warranty service hard to get. Check for a local address, a Michigan license and a track record before signing.
- See also: Common roofing scams in Michigan, How to hire a roofer in Michigan, Home Solicitation Sale
- Substrate
- Whatever surface a roofing material is installed on: the deck, insulation, cover board or an existing roof.
- See also: Deck, Cover Board
- Supplement
- A request to the insurance company to add items or quantities missing from the original estimate, such as code-required items, hidden deck damage or measurement errors. A legitimate supplement is backed by photos, measurements and code references.
- See also: Xactimate, Ordinance or Law Coverage, Insurance roof claims
- Sworn Statement
- Under Michigan's Construction Lien Act (MCL 570.1110), a document a contractor provides to the owner when payment is requested that lists every subcontractor and supplier on the job and what each is owed. It lets you make sure those people get paid. Ask for one before paying. General information, not legal advice.
- See also: Lien Waiver, Construction Lien Act, How to hire a roofer in Michigan
- Synthetic Underlayment
- A woven or spun polymer sheet used as roof underlayment in place of asphalt felt. It is lighter, stronger, more tear-resistant and safer to walk on, and it can stay exposed longer before shingling (per the manufacturer's limits).
- See also: Felt Underlayment, Underlayment, Cap Nail
- Tapered Insulation
- Rigid insulation boards cut with a built-in slope, installed on a flat deck to create drainage toward drains or scuppers. It is the standard fix for ponding on commercial roofs during replacement.
- See also: Cricket, Ponding Water, Polyiso
- Tarping
- Covering a damaged roof temporarily with a tarp secured by battens to keep water out until permanent repairs are made. Tarps are a short-term measure; they degrade in sun and wind.
- See also: Mitigation, Emergency roof repair
- Tear-Off
- Removing the existing roof down to the deck before installing a new one. It lets the crew inspect and replace bad decking, install ice barrier and new flashing, and correct ventilation.
- See also: Roof-Over, Tear-off and replace, Dry-In
- Termination Bar
- An aluminum bar screwed through a membrane at the top of base flashing to hold it tight to the wall, then sealed. It is usually covered by counterflashing.
- See also: Base Flashing, Counterflashing
- Test Square
- A 10-by-10-foot (one square) area marked on a roof slope where an inspector counts hail hits or wind damage. Insurers compare those counts against their own criteria, which vary by carrier, when deciding repair versus replacement.
- See also: Hail Bruise, Haag Certification, Hail damage
- Thermal Cracking
- Also called: Thermal splitting
- Cracks in shingles or low-slope membranes caused by repeated expansion and contraction with temperature swings. On shingles it often appears as straight splits; on membranes it shows at seams and stress points. Freeze-thaw cycles and poor ventilation make it worse.
- See also: Freeze-Thaw Cycle, Roof aging signs
- Thermoset vs. Thermoplastic
- Two families of single-ply membranes. Thermosets like EPDM are cured and cannot be re-melted, so seams are taped or glued. Thermoplastics like TPO and PVC soften with heat, so seams can be hot-air welded.
- See also: EPDM, TPO, PVC Membrane
- Three-Tab Shingle
- A flat, single-layer asphalt shingle with two cutouts creating three tabs. Once the standard, three-tab shingles have largely been replaced by architectural shingles, and matching them on repairs can be difficult.
- See also: Architectural Shingle, Asphalt shingles
- Tile
- Clay or concrete roofing tiles. Both are durable and fire resistant but heavy, and they can crack from impact or freeze-thaw where not rated for it. They are rare on Michigan homes.
- See also: Tile roofing, Batten
- Torch-Down
- Modified bitumen roofing installed by heating the back of the roll with a propane torch to melt it into place. It needs trained installers and careful fire watch, especially near wood and parapets.
- See also: Modified Bitumen
- TPO
- Thermoplastic polyolefin, a white (or light-colored) single-ply membrane for low-slope roofs with heat-welded seams. It is now one of the most common commercial roof membranes.
- See also: TPO roofing, EPDM, PVC Membrane
- Transferable Warranty
- A warranty that can pass to the next owner when the house is sold, often only once and sometimes with a registration step and fee within a set time after closing. Ask for the paperwork when buying or selling.
- See also: Roofing warranties, Roofs when buying or selling a home
- Truss
- A factory-built triangular framing unit that supports the roof, used on most newer homes instead of individual rafters. Trusses should never be cut or altered without an engineer's approval.
- See also: Rafter, Roof sagging
- Underlayment
- The water-resistant layer installed over the deck and under the roof covering, acting as a backup for any water that gets past the shingles. It is felt or synthetic sheet in the field and self-adhered membrane at eaves and valleys.
- See also: Synthetic Underlayment, Ice and Water Shield, Felt Underlayment
- Unit Price
- A fixed price per unit for work that cannot be counted in advance, such as a price per sheet of replaced decking or per linear foot of fascia. Unit prices let you compare how bids handle surprises.
- See also: Allowance, Change Order, How to read a roofing estimate
- Uplift
- Also called: Wind uplift
- The suction force wind creates on a roof, strongest at corners, edges and ridges. Commercial roof assemblies and residential shingles are tested and rated for how much uplift they can resist.
- See also: Wind Rating, FM Approval, Wind damage
- Valley
- The internal angle where two roof slopes meet and water collects. Valleys carry more water than anywhere else on the roof, so they get ice barrier underneath and careful detailing.
- See also: Closed-Cut Valley, Open Valley, Woven Valley
- Vapor Retarder
- Also called: Vapor barrier
- A layer that slows the movement of water vapor from the warm, humid side of an assembly into the cold side. In cold climates it goes on the warm-in-winter side, below the insulation, to reduce condensation in the roof.
- See also: Condensation, Attic Air Bypass
- Ventilation
- Also called: Attic ventilation
- Controlled airflow through an attic from low intake vents to high exhaust vents. It removes heat and moisture, helps prevent ice dams, frost and mold, and is a condition of most shingle warranties. Balance matters more than adding more exhaust.
- See also: Intake Vent, Exhaust Vent, Net Free Area (NFA), Ventilation problems
- Walkway Pads
- Protective pads or rolls laid on a low-slope roof along the paths service technicians use to reach rooftop equipment, so foot traffic does not wear through the membrane.
- See also: Curb, Flat roof systems
- Waste Factor
- Extra material added on top of the measured roof area for cutting and fitting. Simple gable roofs often need around 10 percent; hip roofs and cut-up roofs with many valleys need more.
- See also: Square, Hip Roof, Roofing calculators
- Water-Shedding Roof
- A roof covering that keeps water out by slope and overlap rather than by being watertight, such as shingles, slate, tile and shakes. It is why steep-slope materials fail on low slopes, where water moves slowly and can back up.
- See also: Steep-Slope Roof, Low-Slope Roof
- Wear and Tear Exclusion
- The standard insurance policy exclusion for deterioration from age, weathering, neglect and poor maintenance. Insurers cover sudden accidental damage, such as hail or wind, not a roof that simply wore out.
- See also: Insurance roof claims, Insurance FAQ
- Wet Insulation
- Insulation under a low-slope membrane that has absorbed water from leaks. Wet insulation insulates poorly, adds weight, can rot decking and rust steel decks, and usually has to be cut out and replaced.
- See also: Infrared Moisture Survey, Core Cut
- Wind Damage
- Shingles lifted, creased, torn or blown off by wind. A creased shingle has broken its seal and may lift again even if it lies flat now.
- See also: Blow-Off, Wind damage
- Wind Rating
- A shingle's tested wind resistance. Under ASTM D3161, Class F means tested at 110 mph; under ASTM D7158, Class H corresponds to 150 mph. Ratings assume the shingle is installed and sealed per the manufacturer.
- See also: Class 4 Impact Rating, Nailing Pattern, Wind damage
- Wood Shingle
- A sawn wood roofing unit, usually cedar, smoother and thinner than a hand-split shake. Wood roofs need good airflow beneath them to dry out.
- See also: Shake, Cedar shake
- Workers' Compensation
- Insurance that covers workers injured on the job. If a roofing contractor's crew is uninsured and someone falls, it can complicate things for the homeowner, so ask for the roofer's certificate of insurance showing workers' comp.
- See also: Certificate of Insurance (COI), 12 questions to ask a roofer
- Workmanship Warranty
- The roofing contractor's own guarantee on installation, separate from the manufacturer's material warranty. Its length and terms vary widely, and it is only as good as the company's likelihood of still being around.
- See also: Manufacturer Warranty, Roofing warranties, 12 questions to ask a roofer
- Woven Valley
- A valley where shingles from both slopes are laced across the valley in alternating courses. It is used with three-tab shingles and is generally not recommended for thick architectural shingles.
- See also: Valley, Closed-Cut Valley
- Xactimate
- Estimating software, made by Verisk, that most insurers and many contractors use to price claims line by line using regional price lists that are updated regularly. Seeing roof work described in Xactimate line items is normal; the pricing reflects the software's data, not a negotiated contract price.
- See also: Line Item, Supplement, Insurance roof claims
- Zinc or Copper Strip
- A strip of zinc or copper installed near the ridge so rain carries trace metal down the roof, discouraging moss and algae growth. It works best on the area directly below the strip.
- See also: Algae Streaks, Moss
Glossary FAQ
Roofing Terms People Ask About Most
What is a square in roofing?
A square is 100 square feet of roof surface. Roofers measure and price in squares, so a 25-square roof has about 2,500 square feet of surface. Roof area is always larger than the home's footprint because of slope and overhangs; multiply the footprint by the slope factor (about 1.118 for a 6/12 roof) to estimate it.
What does 6/12 pitch mean?
It means the roof rises 6 inches for every 12 inches it runs horizontally, about a 26.6-degree angle. Roofs 3/12 and flatter are low-slope and need a membrane. Asphalt shingles can go down to 2/12 with a double layer of underlayment, and roofs from about 7/12 up are usually priced with steep charges.
What is the difference between drip edge and gutter apron?
Both are edge metal. Drip edge is required by code on shingle roofs at eaves and rakes and pushes water away from the fascia. Gutter apron extends down into the gutter so water cannot run behind it. At the eaves, many roofers use one or the other depending on the gutter setup; rakes get drip edge.
Is ice and water shield the same as underlayment?
It is one type of underlayment. Regular underlayment (usually synthetic) covers the whole deck and sheds water. Ice and water shield sticks to the deck and seals around nails so it can resist water backing up from ice dams, so it goes at eaves, in valleys and around chimneys and penetrations.
What is the difference between ACV and RCV on a roof claim?
Replacement cost value (RCV) is the cost to replace the roof new. Actual cash value (ACV) is RCV minus depreciation. On a replacement cost policy, the insurer usually pays ACV first and releases the depreciation after the work is complete. On an ACV policy or roof payment schedule, the depreciation is not paid. This is general information, not legal advice; your policy language controls.
What is O&P on an insurance roofing estimate?
Overhead and profit, often shown as 10 percent plus 10 percent. It pays a general contractor to coordinate a job. Insurers generally include it when coordinating multiple trades is reasonably needed, such as roofing plus siding and gutters, and may not on a roof-only claim. Ask your adjuster how your policy handles it.
What is a sworn statement in Michigan?
Under the Michigan Construction Lien Act (MCL 570.1110), a sworn statement lists every subcontractor and supplier on your job and what each is owed. A contractor must provide one when payment is requested. It tells you whose lien waivers to collect so no one can place a lien on your home after you have paid. This is general information, not legal advice.
Can a roofer put new shingles over old ones in Michigan?
Sometimes. The Michigan Residential Code (R908.3.1.1) prohibits a re-cover when there are already two layers, when the existing roof or deck is water-soaked or deteriorated, or over wood shake, slate or tile. Even when it is allowed, a roof-over hides deck problems, and many manufacturers limit warranties on them.
What is a hail bruise?
A soft spot on a shingle where hail fractured the fiberglass mat underneath. It may not look like much at first, but it feels spongy under light pressure and later loses granules and can crack. Inspectors count bruises in 10-by-10-foot test squares to document hail damage.
What does NDL warranty mean on a commercial roof?
No dollar limit. It is a manufacturer warranty that pays to repair covered leaks without a dollar cap for its term. It usually requires an approved installer, a manufacturer inspection when the roof is finished and ongoing maintenance, so read the conditions.
What is a core cut on a flat roof?
A small sample cut through a low-slope roof to see how many layers are there, what insulation is used, whether it is wet and what the deck is. It is patched right away. Core cuts, often guided by an infrared moisture scan, are how you decide between restoring, recovering or tearing off.
Still Have Questions?
Want a Second Opinion on Your Roof?
If a word on your estimate or insurance scope still does not make sense, ask the contractor or adjuster to explain it in writing. Any reputable roofer will. And if you would like another set of eyes on your roof or your paperwork, we are happy to take a look, whether or not you end up hiring us.
Call or text (616) 840-1927 or schedule a roof inspection.
Keep Reading
Related Roofing Resources
How to Read a Roofing Estimate
Line by line, what each item on a roofing bid means and what to compare.
Learn MoreHow to Hire a Roofer in Michigan
Licenses, insurance, sworn statements and lien waivers, step by step.
Learn MoreRoofing Calculators
Squares, slope factors, waste and ventilation math.
Learn MoreRoofs When Buying or Selling a Home
Inspections, disclosures, warranties and what to ask.
Learn MoreSources
What This Page Cites
- Michigan Residential Code 2015 (based on the 2015 International Residential Code), Chapter 9 Roof Assemblies (R905.1.2 ice barriers, R905.2.2 slope, R905.2.8.5 drip edge, R908.3.1.1 re-cover limits) and R806.2 attic ventilation: https://codes.iccsafe.org/content/IRC2015
- Michigan Construction Lien Act, Act 497 of 1980, MCL 570.1101 and following, including 570.1110 (sworn statement) and 570.1118a (payment affidavit): https://www.legislature.mi.gov/documents/mcl/pdf/mcl-act-497-of-1980.pdf
- Michigan Home Solicitation Sales Act, Act 227 of 1971, MCL 445.111 to 445.117: https://www.legislature.mi.gov/Laws/MCL?objectName=mcl-445-112
- Michigan Insurance Code, fraudulent insurance acts, MCL 500.4503: https://www.legislature.mi.gov/Laws/MCL?objectName=mcl-500-4503
- Michigan LARA, residential builder and maintenance and alteration contractor licensing: https://www.michigan.gov/lara
- Michigan Department of Insurance and Financial Services (DIFS): https://www.michigan.gov/difs
- UL 2218 impact resistance and UL 790 / ASTM E108 fire classification of roof coverings: https://www.ul.com
- ASTM D3161 and ASTM D7158, wind resistance of asphalt shingles: https://www.astm.org
- National Roofing Contractors Association (NRCA), The NRCA Roofing Manual: https://www.nrca.net
- ENERGY STAR, sunset of the roof products specification (2022): https://www.energystar.gov