Why low-slope sections in this neighborhood fail first
The grand homes around historic Browne's Addition were built tall, with steep century-old roofs that shed snow well. But the flat porch decks, dormered rear additions, and bay-window roofs that came later sit nearly level - and water has nowhere to run. Low slope means standing water, and standing water finds every seam.
When a flat section behind a parapet wall fails, the leak rarely shows up directly below. It tracks along the framing and surfaces yards away, staining plaster on a floor you'd never connect to the roof. By the time most owners call us, the decking under the old built-up or rolled roofing has already started to soften.
What TPO actually does on a flat roof
TPO is a single-ply thermoplastic membrane that we heat-weld at the seams, so the joints become one continuous sheet rather than a row of glued laps waiting to peel. A properly welded TPO roof has no seams that can be pulled apart by freeze-thaw.
- Reflective white surface that doesn't bake in summer sun on an exposed deck
- Welded seams instead of adhesive or tar that brittles with age
- Flexible enough to handle the expansion and contraction Inland NW temperature swings cause
- Flashes cleanly into the brick parapets and masonry walls these homes are full of
For the right low-slope situation we'll also talk through modified-bitumen options, but on most Browne's Addition additions TPO is the system we trust to last.
Built for snow load, ice, and the flat-roof problem
A flat roof can't shed a snowpack the way the steep main roofs over Coeur d'Alene Park do. The snow sits, melts from below, refreezes at the edges, and forms ice dams right at the parapet line. That cycle is exactly what destroys a low-slope roof if the membrane and drainage aren't done right.
We build positive slope into the deck wherever the framing allows, set internal drains and scuppers that won't clog with needles and grit, and detail the flashing so meltwater stays on the membrane and off the brick. Tapered insulation under the TPO does double duty - it moves water toward the drains and cuts the heat loss that drives those ice dams in the first place.
Working on a hundred-year-old home
The brick mansions here weren't framed to modern spans, and the additions on the back were often added piecemeal over decades. We tear off carefully, check the decking and framing before we re-cover, and replace rot rather than roofing over it. A new membrane is only as good as the wood it's fastened to.
We also respect the building. Flashing terminations against original masonry get done so they shed water without hacking into historic brick, and we keep the flat sections low-profile so they stay invisible from the street while the steep slate-look roofs above stay the star.
Coordinating flat and steep roofs together
Most homes in Browne's Addition aren't all flat or all steep - they're both, often meeting at an awkward transition where a low-slope addition tucks under a tall gable. That junction is the single most common leak point we find.
Because we handle both systems, we tie the TPO into the shingle or steep-roof field as one detail instead of leaving a seam between two trades. If your steep roof is also aging, we can sequence both so the transition flashing is built once, correctly. Learn more about full roof replacement when the whole roof is due.
What you get with DG Contracting
We're a family-owned, GAF Master Elite contractor - a credential held by the top 2 to 3 percent of roofers nationwide - licensed and insured in both Washington and Idaho. Our work is backed by a 15-25 year workmanship warranty plus GAF's Golden Pledge coverage where it applies.
Estimates are free and so is the walkthrough of your low-slope sections. When a replacement includes the steep roof too, we'll throw in up to a 15-25 year workmanship warranty, and flexible financing keeps the project workable. Call (509) 209-1894 to set up a look at your roof.
