When The Back Roof Is Past Patching

Signs The Rear Roof Is Done Taking Patches

A low-slope roof rarely fails in one afternoon. It wears out a seam at a time, and each repair buys a season until the repairs cost more than they save. These are the conditions that tell us a section has reached the end:

• Soft spots underfoot, where the deck below has been wet long enough to lose its stiffness.
• Ponding that is still sitting on the surface long after the rain has stopped.
• Blisters and bubbles spread across the field, a sign that moisture is trapped between layers.
• A stained or sagging ceiling in the back room, especially one that returns after every repair.

Any one of those can be a repair. Two or three together usually mean water has been getting in for a while and the deck under the membrane has been soaking it up. At that point, a new layer laid over the old one would simply seal the damage in.

Inside the house, the back room usually tells the story before the roof does. Paint bubbling along the wall where the addition meets the original house points at the tie-in. A stain in the middle of the ceiling points at the field. A musty smell with no visible stain often means the insulation above has been wet for a while and the deck is going soft. We go up and look either way, because the roof is where the answer is.

Down To The Boards

A replacement on these houses means a full tear-off. Every layer comes up, including any that somebody installed over an older roof instead of removing it, until the crew is standing on bare deck. On the postwar houses here that deck is wood plank or early plywood, both good materials for as long as they stay dry.

Wet ones do not stay good. We walk the exposed deck, mark every board that is soft, split or coming apart in layers, and cut it out. New decking goes down before anything else does. Those boards show up in your photo report, so the decking line on the bill matches something you can actually look at.

What Goes Back Down

With sound deck underneath, the new membrane goes on. Flat roofs are a specialty of ours, and we install TPO, EPDM and torched modified bitumen, so the system gets chosen for the section rather than for whatever is already on the truck. On a small back room or garage, a granulated cap sheet like the one in the photo at the top of this page is a common pick, since the mineral surface takes the sun that would otherwise age the asphalt beneath it.

Where the roof runs into a brick wall, the membrane turns up the wall and new metal counterflashing covers the top of it, so the section is sealed along every edge where water could reach it.

Building In The Slope The Old Roof Never Had

Bellwood sits flat and drains slow, and many of these back roofs were framed close to dead level. Water with nowhere to go sits on the membrane until it finds a seam. When we rebuild, the new roof gets positive slope toward the edge, built into the layers under the membrane so the pitch is there before the finished surface goes on. On a garage, that usually means pitching toward whichever side lets the gutter reach a downspout without crossing the driveway or a walk.

At that edge, new metal passes the water to a gutter instead of letting it run down the brick. A low roof that empties onto the ground beside the house only moves the leak from the ceiling to the basement, and these older foundations were never waterproofed to handle that.

Where The Flat Section Meets The House

The joint between the low roof and the steep main roof is where most rear additions start leaking. Two different roofing systems meet there, usually installed years apart by different people. On a replacement we lift the bottom courses of shingles, run the new membrane up beneath them, and lay the shingles back down over it so water stays on top the whole way down.

If the main roof is close to the end of its own life, you hear that from us while we are up there. Sometimes the right call is rebuilding the tie-in now and planning the house roof for later.

One Trip For The Garage And The House

Detached garages behind these homes are often low-slope and older than the roof on the house. When both need work, we do them while the crew and the dumpster are already on site, and the quote lists the garage and the house as separate lines. Do both, or do one now and keep the other number for when you are ready. The garage is also the roof nobody checks until the rafters start to stain, so it is worth a look whenever the house is being priced.

Guardian is a second-generation roofer working out of Alsip since 2013. Angelo Ristich learned the work alongside his father Frank, now runs the company, and is the one you talk to about your roof. If you want the full rundown on tear-offs beyond Bellwood, read our flat roof replacement page. Back rooms and garages we have already redone are pictured in the gallery, and photos of yours can be sent in from the contact page.