Waterproofing in Seattle, WA
Commercial waterproofing seals the vulnerable transitions where most leaks actually start — parapet walls, deck-to-wall joints, plaza decks, and below-grade areas. It uses membranes, sealants, and flashing details engineered for standing water and thermal movement, not the shingles-and-underlayment approach used on sloped residential roofs.
Top Waterproofing Contractors in Seattle
Listings updated July 2026
Seattle Roof Systems
Seattle, WA
Seattle Roof Systems provides commercial flat and low-slope roofing services in Seattle, WA — TPO, EPDM, modified bitume...
Perdigon Roofing
Seattle, WA
Seattle metal roofing contractor specializing in commercial metal systems, PermaLock shingles, and repairs for North Sea...
Eco Roofing & Roof Replacement
Seattle, WA
Licensed Seattle roofing contractor offering replacement, repair & cleaning for multifamily, retail & mixed-use properti...
Three Tree Roofing
Seattle, WA
Three Tree Roofing is Seattle's #1 CertainTeed-rated commercial roofer, delivering flat, metal & shingle systems across...
Premier Roofing Seattle
Seattle, WA
Premier Roofing Seattle provides commercial flat and low-slope roofing — TPO, EPDM, modified bitumen, metal — for office...
Mountaintop Metal Roofing
Seattle, WA
Mountaintop Metal Roofing offers lifetime metal roofing installation, overlays, and solar compatibility for commercial p...
King Quality Roofing
Seattle, WA
King Quality Roofing provides commercial roof repair, replacement & 24/7 emergency services for businesses across Seattl...
The Seattle Roofing Company
Seattle, WA
GAF Master Elite certified commercial roofer serving Seattle & Puget Sound. TPO, flat roofs, multifamily. 24/7 emergency...
Pacific Roofing Company Seattle
Seattle, WA
Pacific Roofing Company Seattle serves commercial properties across King County with flat roofing, repairs, and replacem...
Tekline Roofing
Seattle, WA
Seattle commercial roofer specializing in TPO, PVC, metal & flat roofing for multifamily, office & retail properties acr...
A Better Roofing Company
Seattle, WA
Family-owned Seattle roofing contractor serving King County; licensed, bonded & insured with workmanship warranty and no...
Emerald Roofers Seattle
Seattle, WA
Seattle commercial roofer specializing in PVC, flat roofs, metal systems, and maintenance programs for office, retail, a...
Interlock Metal Roofing (PNW) Inc. - Seattle
Seattle, WA
Seattle metal roofing contractor offering 50-year transferable warranties, Class A fire-rated aluminum systems, and mult...
Andrew & Sons Roof Repair
Seattle, WA
Seattle commercial roof repair specialist covering flat roofs, waterproofing, flashing, storm damage & full replacement...
Rainier Roofing Company
Seattle, WA
Rainier Roofing serves Seattle & Bellevue commercial properties with TPO, PVC, metal & modified bitumen — 10-year crafts...
M&H Services LLC
Seattle, WA
Licensed Seattle roofing contractor offering 24/7 emergency response, roof replacement, and repairs across King, Pierce,...
Guardian Roofing, Gutters & Insulation
Seattle, WA
Seattle commercial roofer offering 24/7 emergency response, GAF & Owens Corning certifications, flat/low-slope systems,...
State Roofing & Exteriors
Seattle, WA
GAF Master Elite certified commercial roofer serving Seattle & Puget Sound. 24/7 availability, multifamily & mixed-use r...
Maritime Roofing and Construction
Seattle, WA
Veteran-owned, licensed Seattle roofing contractor serving commercial & multifamily properties with flat, metal & shingl...
A1 Commercial Roofing
Seattle, WA
A1 Commercial Roofing in Seattle, WA provides TPO, EPDM, metal, and modified bitumen roofing for commercial and industri...
What to Expect from Waterproofing
Initial consultation and site assessment
Leak-source diagnosis (not just the visible interior stain)
Written proposal with detailed scope of work
Repair matched to your existing system to protect the warranty
Final walkthrough and documentation
Waterproofing Pricing in Seattle
Pricing varies by contractor and project scope
Request quotes from multiple contractors to compare pricing. Factors that affect cost include system size, building type, equipment brand, warranty terms, and urgency. Always ask for an itemized written estimate before authorizing work.
Get free quotes from Seattle contractorsRelated Repair Services in Seattle
Frequently Asked Questions — Waterproofing in Seattle
How much does waterproofing cost in Seattle, WA?
Waterproofing costs in Seattle vary based on system size, building type, and scope. Request quotes from multiple contractors through My Roofing Tech to compare pricing. Always ask for itemized written estimates before authorizing any work.
How do I choose the best waterproofing contractor in Seattle?
Look for contractors with specific experience in commercial roofing (not just residential). Verify their state license, insurance, and bonding, and confirm they're certified and experienced with your roof system. Check reviews from similar commercial properties. Ask about their workmanship warranty and their typical response time for follow-up issues.
How long does waterproofing typically take?
The timeline depends on the size and complexity of your roof system and the scope of work. Simple repairs often complete in a few hours. Larger installations and replacements may take several days to a few weeks. Emergency service typically stabilizes the problem within hours even when the permanent fix requires returning with materials.
Is waterproofing covered by building insurance?
Generally, sudden storm or accidental damage may be covered by commercial property insurance, while gradual wear and deferred-maintenance issues are not. Contact your insurance provider and ask specifically about coverage for your roof system. A documented inspection report strengthens any claim you file.