Garage, Shed and Pole Barn Roof Repair: What Changes and Is It Worth It

The 2015 Michigan Residential Code exempts several small projects from building permits in Section R105.2. The one that matters here: one-story detached accessory structures do not need a building permit if the floor area does not exceed 200 square feet. The same section says an exemption from permits does not authorize work that violates the code, so the work still has to be done correctly. Section R105.2.2 adds that ordinary repairs do not require application or notice to the building official, though local departments decide what counts as ordinary.

A detached garage over 200 square feet is a regular accessory building under the code. Replacing its roof may need a permit like a house roof, depending on your city or township. Repairs usually do not.

Farm buildings are a separate case. Michigan's Stille-DeRossett-Hale Single State Construction Code Act defines a building, and that definition says it does not include a building incidental to the use for agricultural purposes of the land on which it is located, if it is not used in the business of retail trade. Some townships, such as Georgetown Township in Ottawa County, have the owner file an agricultural use exemption application and affidavit, so check with yours before assuming it applies.

Detached buildings are not covered under the dwelling part of a standard homeowners policy. The ISO HO-3 special form covers them under Coverage B, Other Structures: structures on the residence premises set apart from the dwelling by clear space, including those connected only by a fence or utility line. In that form, the Coverage B limit is not more than 10 percent of the Coverage A dwelling limit, and using it does not reduce Coverage A. Many insurers let you raise it by endorsement.

The same form excludes other structures from which any business is conducted, structures used to store business property (with an exception for property owned by an insured or a tenant), and structures rented to someone who is not a tenant of the dwelling unless used solely as a private garage. A pole barn used for a side business may not be covered under your homeowners policy at all.

The rules about sudden damage versus wear and tear apply to outbuildings just as they do to the house. A tree through the garage roof is a different claim from a rolled roof that has been leaking for years. Check your declarations page for the Coverage B limit and ask your agent before assuming.

The math on an outbuilding is different from a house. A repair can be worth far more than its cost on a detached garage that protects cars, tools and a workshop, or on a pole barn full of equipment. On a small kit shed with a soft floor and rotted corners, the roof repair can cost more than a new shed.

Contractor minimums matter here. Most roofers have a minimum charge for any visit; at Stellar Roofing Company every repair starts at $500. That makes a tiny shed roof a poor candidate for a professional repair on its own, and a good candidate to bundle with work on the house: one visit that handles three small problems costs less than three visits.