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TRUSTED BY SEATTLE, WA HOMEOWNERS

  • Average homeowner rating star icon4.7
    Average homeowner rating
  • Verified reviews icon103
    Verified basement waterproofing services reviews

Find Basement waterproofing pros in Seattle

Avatar for Insulation Co., LLC - Removal & Clean Outs
Insulation Co., LLC - Removal & Clean Outs
4.9(
226
)
Foundation, Basement or Crawlspace - Waterproofing / Encapsulation

Serving Seattle, WA and surrounding areas

Approved

In business since 2009

Free estimates

Warranties offered

"I contacted a few companies for quotes and Insulation Co was local to Edmonds, so I engaged them. Jo provided a fast quote over email, which I found odd as the other guys made an effort to come out and view the job and obviously high pressure sell you.... The quote was inline and lower than other guys, so based on that and the great reviews they had, I went with it. Other companies had as many 1 star reviews as 5 star and that was a deal breaker. Jo has almost all 5 Star reviews...The team was able to schedule a time within a week and did all the work while we were out of town. I'm very happy with the results. Did a crawl space insulation, vapor barrier, all the AC duct work and even the adjoining wall to the basement, which I didn't expect. Were in and out in half a day, all cleaned up and professional. House floors are noticeably warmer. Highly recommend this local small business."
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2
3
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+46

Response time5 hrs
Recommended by49%of homeowners
Avatar for TerraFirma
TerraFirma
4.0(
100
)
Foundation, Basement or Crawlspace - Waterproofing / EncapsulationBasement Drainage Channels - RepairBasement Drainage Channels - Install

Serving Seattle, WA and surrounding areas

Approved

In business since 2005

Free estimates

Warranties offered

"Had huge foundation problems at a project of mine on the waterfront. We used terrafirma to both waterproof the entire basement AND lift the foundation. 10/10 would recommend. extremely communicative, very knowledgeable, and even brought a crew in from Oregon to help us stay on schedule. Oscar and jorge got the job done extremely quickly and Seth was fantastic as my project manager."
A System Design Specialist helping a homeowner
Encapsulating a crawl space
Fleet of vehicles in our Portland, Oregon locatio
Loading up our truck for a piering job
Loading up a truck for a waterproofing job

+33

Response time2 hrs
Response rate100%
98 neighbors recently requested a quote
Avatar for Wu Construction
Wu Construction
4.6(
238
)
Foundation, Basement or Crawlspace - Waterproofing / EncapsulationBasement Drainage Channels - InstallBasement Drainage Channels - Repair

Serving Seattle, WA and surrounding areas

Approved

In business since 1983

Free estimates

Emergency services offered

"Better than I could have asked for. They came up with a GREAT solution to my basement leaking issues (I had a river in my basement last winter) thus far this fall not a drop. His option was faster, cheaper and more effective than the other 3 companies i had bid the job. I could not be happier!"
Additional Photos
Additional Photos
Additional Photos
Additional Photos
Additional Photos

+11

Response time10 mins
Response rate100%
34 neighbors recently requested a quote
Avatar for Groundworks
Groundworks
4.3(
314
)
Foundation, Basement or Crawlspace - Waterproofing / EncapsulationBasement Drainage Channels - RepairBasement Drainage Channels - Install

Serving Seattle, WA and surrounding areas

Approved (Corporate)

In business since 1995

Free estimates

Emergency services offered

"Had Groundworks install a drainage system and sump pump in our home’s crawl space. Anthony and his crew, Jordon, Uriel, and James were Outstanding. It was a three day job. They were on time every day and worked their tails off each day. It was a muddy job in cramped quarters. They never complained. Anthony kept me updated on the progress they made each day. Anthony shared pictures of the job as it progressed. They cleaned up the job site each day. Anthony went over all the details at the completion of the job and answered all of my questions. The whole process was Great. From the initial inspection done by Kristy to the office staff and the installation. The communication was also Great. I highly recommend Groundworks for a complete and thorough job."
Foundation
Foundation
Foundation
Concrete
Concrete

+16

Response time2 days
142 neighbors recently requested a quote
Recommended by83%of homeowners
Avatar for Iconiq Construction, LLC
Iconiq Construction, LLC
4.9(
31
)
Foundation, Basement or Crawlspace - Waterproofing / Encapsulation

Serving Seattle, WA and surrounding areas

Approved

Super Service Award Winner

In business since 2023

Free estimates

Warranties offered

"Iconiq Construction Service did an amazing job finishing our basement. The team was professional, efficient, and detail-oriented. The results were outstanding, creating a functional and beautiful space. Highly recommend their services!"
kitchen remodel
Kitchen remodel
addition project
bathroom remodel
bathroom remodel

+2

Response time1 day
Response rate94%
9 neighbors recently requested a quote
Avatar for Harts Plumbers, Electricians, & HVAC Technicians
Harts Plumbers, Electricians, & HVAC Technicians
4.6(
1,247
)
Basement Drainage Channels - InstallBasement Drainage Channels - Repair

Serving Seattle, WA and surrounding areas

Approved

Super Service Award Winner

In business since 2013

Emergency services offered

Warranties offered

"Dylan from Harts Services was prompt, professional and courteous... he scoped out three unfinished basement floor drains to determine why they weren't draining properly... he even invited me to observe the process which I did... Dylan was able to diagnose the problem and provide me with viable solutions and costs and within a short period of time emailed me that information to make an informed decision... quite pleased with the service and would/will not hesitate to engage Harts Services again"
Pipe llining
Pipe relining
Pipe relining
Camera inspections
Response time50 mins
Response rate100%
23 neighbors recently requested a quote
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Showing 1-10 of 209
Basement Waterproofing questions, answered by experts

Before starting basement waterproofing in Seattle, confirm if your project requires permits, especially for exterior excavation or drainage work. Schedule waterproofing during the drier summer months to minimize weather-related delays. Arrange for a soil analysis to determine drainage needs specific to your property. Notify neighbors if excavation may affect shared boundaries, and request detailed project timelines and references from local contractors experienced with Seattle’s rainfall and soil conditions.

Helpful?

In Seattle, interior basement waterproofing projects typically take between three and ten days, depending on the size and condition of the basement. Exterior waterproofing, especially full-perimeter drainage or foundation sealing, can extend from one to six weeks. Rainy weather may cause additional delays, particularly in spring and fall. Factoring in planning, contractor scheduling, and permit approval, the entire process often spans two to four months from start to finish.

Helpful?

In Seattle, basement waterproofing projects benefit from materials designed for persistent rain and clay-heavy soils. For interior waterproofing, use high-grade epoxy injections for crack repair, vapor barriers with superior moisture control ratings, and dehumidifiers built for the Pacific Northwest climate. Exterior solutions should include elastomeric membranes, drainage boards, and bentonite clay panels, which perform well in local soil. Installing perimeter French drains and reliable sump pumps further protects against Seattle’s frequent groundwater intrusion.

Helpful?

Seattle offers a range of basement waterproofing professionals, including specialists focused on interior moisture control, exterior foundation sealing, and drainage system installation. Some contractors are experts in structural repairs for older Seattle homes, while others provide mold remediation or crawl space encapsulation. Consulting with a local structural engineer can help assess complex issues. Always verify contractors’ experience with Seattle’s unique soil and rainfall patterns to ensure effective, long-lasting solutions.

Helpful?

Basement waterproofing in Seattle delivers immediate benefits like reduced humidity, improved air quality, and prevention of mold growth. Over the long term, it safeguards your home’s foundation from water damage, preserves property value, and enhances energy efficiency during damp winters. Waterproofing also helps prevent structural shifting common in Seattle’s soil, making your basement a healthier, more usable space while reducing the risk of costly repairs in the future.

Helpful?

The Seattle, WA homeowners’ guide to basement waterproofing services

From average costs to expert advice, get all the answers you need to get your job done.