Last updated: 2026-08-30
Tacoma Roofing is a roofing company serving Tacoma and Pierce County, and flat roof replacement is one of the services we handle most. This page covers what the work involves here specifically — the climate, the code, and what it costs — rather than what it involves in general.
What we do on the first visit
The first visit is an inspection, not a sales call. We walk the roof with you, check the deck from the attic side where we can, count valleys and penetrations, and note the pitch and how much staging or safety equipment the job needs. We confirm whether any prior layers are on the roof already — code allows a maximum of two before a full tear-off is required — and then you get a written per-square price with tear-off and any deck repair as separate lines.
If we think repair is the better spend than replacement, or a different material suits your situation better, we say so on that visit — including when it means the smaller job for us.
What's included
- Membrane system (TPO, PVC, or EPDM) selected for the roof's specific drainage and use
- Full tear-off with deck inspection, rotten sheathing replaced and priced separately
- Drainage and flashing detailing at every roof edge and penetration, addressing ponding-water risk
- Insulation upgrade options where the existing system is under-insulated
- Written price before work starts
- Site cleanup and haul-away of the old membrane
- Detailing appropriate for additions and porch roofs, not just whole-building jobs
- A drainage-slope fix built into the install, not a patch over an existing ponding problem
What this costs in Tacoma
Flat Roof Replacement runs $835–$2,080 roofing square (100 sq ft), installed in this area. Derived from Valentine Roofing's Tacoma-specific single-ply membrane total ($20,800-$52,000 for a full job) divided over a typical 25-square home; commercial-scale TPO/PVC for larger Pierce County buildings, including work near the Port of Tacoma corridor, is priced separately on the commercial roofing page. The things that move a job up its range are tear-off, how much deck repair is needed, pitch, and how many valleys and penetrations your roof has. If you want a number before you call, the roof cost calculator will get you close.
When it needs doing
- Visible ponding water more than 48 hours after rain
- Membrane seams separating or bubbling
- Interior ceiling stains under a flat-roofed section
- A flat roof approaching or past its membrane's rated service life
- Water pooling near a roof drain or scupper
- An addition or porch with a flat section that's never been resealed
Related reading
These go deeper on the questions that come up most on this job: