Issaquah and Eastside King County

Commercial Roofing in Issaquah, WA

TPO, EPDM, and modified bitumen roofing for Issaquah and Eastside King County commercial buildings — new installation, re-cover, repair, and maintenance programs that reduce leak calls.

Typical range: $800–$1,450 per roofing square (100 sq ft), TPO/EPDM installed

Call (425) 642-1901

Commercial Roofing underway on a property in Issaquah, WA

Full tear-off, not a cover-up

Permit pulled on every job

Written price before work starts

Never a damaging pressure wash

Old roofing hauled away

Last updated: 2026-08-26

Roofing Issaquah is a roofing company serving Issaquah and Eastside King County, and commercial roofing 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

On-site roof assessment covering membrane condition, seams, drainage, and penetrations
A written scope and price identifying whether the job is an overlay, new construction, or full tear-off reroof
TPO, EPDM, or modified bitumen membrane installation to manufacturer and code wind-uplift spec
Tapered insulation or drainage correction where standing water is a recurring problem in this area's 60-65 inches of annual rain
Flashing and penetration detail work at every rooftop unit, drain, and wall termination
Minimal business-disruption scheduling — we work around your operating hours where possible
A maintenance program option to catch small failures before they become leak calls
Warranty documentation appropriate to the membrane system installed

What this costs in Issaquah

Commercial Roofing runs $800–$1,450 per roofing square (100 sq ft), TPO/EPDM installed in this area. A Seattle-area contractor source quotes $8-$14.50/sq ft fully installed for commercial TPO, which for a 3,000 sq ft roof works out to that same source's cited $24,000-$43,500 total job price; Angi's WA-statewide low-slope/single-ply anchor (roughly $26/sq ft) runs higher and blends more markets and roof types — see the commercial cost guide for the full reconciliation. 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

Standing water that doesn't drain within 48 hours after rain
Visible seam separation or membrane punctures
Recurring leak calls despite previous spot repairs
Roof is approaching or past its membrane system's expected service life
Planning a rooftop equipment change and need the roof assessed first
No current maintenance program and want to get ahead of failures

DIY patch, the cheapest bid, or the job done properly

	DIY weekend	Cheapest bid	Done properly
Moss removal	Pressure washer — strips granules, drives water under tabs	Quick scrape, no treatment applied	Gentle hand/brush removal plus treatment, gutters cleared
Material grade	Bargain shingle off the shelf, no algae resistance	Standard grade, warranty terms rarely disclosed	Algae-resistant or premium-grade material with a real warranty, disclosed in writing
Underlayment	Whatever’s left over, felt paper reused	Minimum-code synthetic underlayment	High-wind-rated synthetic underlayment, ice-and-water membrane at eaves and valleys
Deck check	Not considered	Skipped unless asked	Checked from the attic side where access allows, repaired if moss has reached it
Permit	Often skipped	Sometimes skipped	Pulled and inspected every time
If it fails	Your weekend, again, now with a worse leak	Chasing a phone number that stopped working	We come back and fix it

How it works

How commercial roofing runs

Roof assessment
We walk the roof, check drainage and ponding, inspect every seam and penetration, and determine whether this is an overlay, new-construction, or full tear-off job.
Written scope and price
You get a written scope specifying membrane type, insulation, and any drainage correction, with a price broken out by line item.
Installation
Membrane installed to manufacturer wind-uplift spec for this region, with flashing and penetration detailing done to code.
Final walkthrough and maintenance option
We walk the finished roof with your facilities team and discuss a maintenance program if ongoing inspection makes sense for your building.

Get a free commercial roofing estimate

A real person answers. We walk the roof with you, check the deck, and give you a written per-square price — at no charge and with no pressure.

Call (425) 642-1901

Questions

Commercial Roofing questions

How much does commercial TPO roofing cost per square foot on the Eastside?

Installed TPO runs roughly $8-$14.50 per square foot in the Seattle area, which converts to about $800-$1,450 per roofing square. An overlay/recover job sits toward the lower end; a full tear-off reroof with new insulation runs toward the higher end. We give you a specific number after the site assessment, not a sight-unseen quote.

TPO, EPDM, or modified bitumen — which is right for my building?

It depends on your roof's slope, drainage, rooftop equipment load, and budget. TPO is the most common modern choice for reflectivity and seam-welding; EPDM has a long track record and lower material cost; modified bitumen suits roofs with heavier foot traffic or equipment. See our comparison guide for the full breakdown.

How often does a commercial flat roof need replacing in this climate?

Issaquah's near-daily winter moisture and above-average rainfall (60-65 inches a year) shortens membrane life compared to drier climates if drainage isn't working correctly — a well-maintained TPO or EPDM system still commonly reaches 20-30 years, but standing water and unaddressed seam failures can cut that significantly. A maintenance program catches the issues that shorten roof life before they become replacement-driving problems.

Can you work around our business hours?

Yes — we schedule around your operating hours wherever the job allows, and we coordinate directly with your facilities team rather than leaving you to manage the crew.

Do you charge for an estimate?

No. Estimates are free across Issaquah and Eastside King County, including the drive. We walk the roof with you, check the deck from the attic side where we can, and hand you a written per-square price with tear-off and any deck repair broken out as their own lines.

Also worth a look

Related services

Flat Roof Replacement

Residential flat and low-slope roof replacement for Issaquah homes — additions, porches, and full low-slope sections — with drainage correction built into the job, not an afterthought, in a climate that gets 60-65 inches of rain a year.

Roof Inspection

Professional roof inspections for buying, selling, or just knowing where you stand — a written condition report, not a sales pitch, covering material condition, moss/algae extent, flashing, and deck.

Storm Damage Roof Repair

Windstorm and storm-damage roof repair for Issaquah and Eastside King County, with documentation built for an insurance claim from the first visit — and an honest read on what's actually storm damage versus pre-existing moss or age-related wear.