Does this price include tear-off of the old membrane?

Not automatically — whether tear-off or an overlay is appropriate depends on the existing roof's condition, and we quote each separately once we've assessed it.

Which membrane is cheapest?

TPO is generally the most cost-competitive per square foot for most commercial applications; EPDM and modified bitumen each have situations where they're the better technical choice despite a different price point. See our TPO vs. EPDM vs. modified bitumen guide.

Does ponding water add to the cost?

Addressing drainage design to eliminate standing water — rather than just re-covering the same slope — can add cost upfront, but it's what actually extends the new roof's service life, so we price it as a real line item, not an upsell.

Cost Guide

Commercial Flat Roof Cost Per Square Foot in Everett, WA

What commercial flat roof replacement costs per square foot in Everett — TPO, EPDM, and modified bitumen — with a worked example for a typical 3,000 sq ft building.

Commercial flat roof replacement in the Everett/Seattle area runs roughly $8-$14.50 per square foot fully installed, depending on membrane type and existing drainage condition. A typical 3,000 sq ft commercial roof runs $24,000-$43,500 installed.

Published 2026-08-30 · Updated 2026-08-30

Commercial flat roof pricing is usually quoted per square foot rather than per roofing square, since commercial jobs are typically priced against a building’s actual footprint and membrane spec rather than a residential material list.

The per-square-foot range

Based on a Seattle-area contractor-published rate, commercial TPO membrane replacement runs roughly $8-$14.50 per square foot fully installed. That range reflects:

$8-$10/sq ft — straightforward tear-off and replace on a roof with sound decking and adequate existing drainage
$10-$12.50/sq ft — typical mid-range job with some flashing and edge-detail work
$12.50-$14.50/sq ft — jobs requiring deck repair, drainage redesign, or insulation upgrades

Worked example: a 3,000 sq ft commercial roof

At $8-$14.50/sq ft, a 3,000 sq ft commercial roof runs $24,000-$43,500 installed. The actual number within that range depends on membrane choice, deck condition, and how much drainage or insulation work the building needs beyond a straight membrane swap.

What pushes the price toward the high end

Ponding water history. If water sits on the roof more than 48 hours after rain, the drainage design itself needs addressing, not just the membrane on top of it.
Deck and insulation condition. Wet or deteriorated insulation under the membrane has to come out, which adds both material and labor.
Roof-edge and penetration count. More HVAC units, drains, and roof-edge transitions mean more detailed flashing work per square foot.
Business-hours coordination. Scheduling work around an operating business rather than a vacant building can add modest cost for staged work.

Membrane choice affects the number too

TPO tends to sit at the more cost-competitive end of the range for most straightforward applications; EPDM and modified bitumen can be the better technical choice in specific situations despite sometimes running higher. See our TPO vs. EPDM vs. modified bitumen guide for how to choose.

What to budget

Plan on $8-$14.50 per square foot as your working range, and expect the actual number to depend heavily on what our inspection finds under the existing membrane. A free on-site assessment is the only way to get a number specific to your building.

The bottom line

If you want this priced for your own roof rather than in ranges, we come out and inspect at no charge across Everett and Snohomish County. You get a written per-square price with tear-off and any deck repair broken out separately. Call (425) 382-7590.