What the Job Involved
- Problem:
- Leaked every rain. Four layers of roofing, the newest installed four years earlier by a low-bid contractor and failed after two. Rotted soffit, fascia, and rafter tails underneath
- Work performed:
- All four layers removed to the original wood deck; damaged soffit, fascia, and rafter tails replaced; parapet wall reframed and secured; new fully adhered 60 mil EPDM; new door sill flashing; counter flashing at the wall in place of an exposed termination bar
- Time:
- One and a half days
- Cost:
- Around $10,800
- Warranty:
- 15 years
How It Went
This flat roof leaked every time it rained. When we opened it up we found four layers of roofing stacked on top of each other, and the top layer was only four years old.
That top layer is the story. Four years before we got there, the owner had hired the cheaper contractor. He cut several corners, and the roof failed catastrophically after two years. So the owner paid for a flat roof, got two years out of it, and then paid for another one. That is what "cheaper" costs.
We removed all four layers down to the original wood roof deck. Under them we found the damage a leaking flat roof always leaves behind: rotted soffit, rotted fascia, and several rotted rafter tails. We replaced all of it, then properly reframed and secured the parapet wall.
Then the new roof: a fully adhered 60 mil EPDM rubber membrane, bonded to the deck. At the door we installed new sill flashing. Where the roof meets the wall we installed counter flashing instead of the exposed metal termination bar you usually see on a flat roof. Same watertight result, without the industrial look on the side of somebody's house.
A day and a half of work, about $10,800, fifteen-year warranty.
How This Residential EPDM (Rubber) Flat Roof Job Was Done
- 1The section as we found it, tarped over while the failed roof waited to come off.
- 2The old built-up roof comes off in sheets, down to the bare deck underneath.
- 3New sheathing goes down, with the perimeter built up so water is directed rather than left to pond.
- 4A coverboard over the deck gives the membrane a smooth, continuous surface to bond to.
- 5The membrane is bonded down and run up the wall, then terminated — the detail that decides whether a flat roof lasts.
- 6The finished section, sitting flat and draining clean where a shingle roof would have failed.
