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Products & Services

Basement Waterproofing
Waterproof Wall & Floor Products
DryTrak Basement Water Control System
FlexiSpan Wall Crack Repair
Floodring Water Heater Protection
Basement Dehumidifier
Sump Pump Solutions
Triplesafe Sump Pump
SuperSump Sump Pump
UltraSump Sump Pump
SmartSump Sump Pump
Interior Drainage Systems
Exterior Drainage Systems
Waterguard® Drainage System Drytrak®
Monolithic Floor Drains
SmartPipe Drain
Trench Drain WaterGuard®: Iron Ochre System (IOS)
Flowguard Drain
Well duct Window Well Drain
Bright Wall Basement Wall Panels
Warrantied Products & Solutions

Crawl Space Repair & Encapsulation
Crawl Space Moisture Barrier System
Crawl Space Structural Repairs
Crawl Space Access Wells & Doors
Crawl Space Sump Pumps
Triplesafe Sump Pump
SuperSump Sump Pump
UltraSump Sump Pump
SmartSump Sump Pump
Downspout Extensions

Foundation Repair
Pier Systems
Push Piers
Slab Piers
Helical Piers
Smart Jack Crawl Space Support Posts
Foundation Wall Repair
Geo-Lock Wall Anchors
Powerbrace Basement Wall Repair System
CarbonArmor Reinforcing Basement Wall System
Bowing Foundation Wall Repair
Shotcrete Spray Concrete
Concrete Lifting

Concrete Repair
Concrete Driveway Repair
Concrete Pool Deck Repair
Concrete Walkway Repair
Concrete Patio Repair
Concrete Leveling & Lifting
Mudjacking & Slab Jacking Alternatives
NexusPro Cracked Concrete Repair

Earthquake Retrofitting

Free Estimates & Inspections

Company Awards
HomeAdvisor - Best Of 2020 Award
TerraFirma was proud to have received the 2020 HomeAdvisor 'Best Of' Award. This award recognizes only the top percent of... [Read more]
Elite Service Professional Award
By receiving no homeowner complaints and having more than five five star ratings on our profile, TerraFirma was awarded the... [Read more]
Home Advisor Top Rated Company
TerraFirma earned the "Top Rated" award from Home Advisor, a home improvement website that millions of homeowners trust to help... [Read more]
More Awards

TerraFirma serving King County, WA

Happy Customers Surrounding King County, WA
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Experts in Basement Waterproofing in King County, WA

TerraFirma is your local expert contractor for all your basement waterproofing needs in King County, WA. Having a wet, water damaged basement can cause numerous problems in your home including foundation problems and mold. In addition to our basement waterproofing services, we also offer services such as crawl space repair and sump pumps. 

Since 1995, TerraFirma has been the contractor that Washington can trust to get the job done right the first time. Our team of trained experts use only high quality materials from the best manufacturers in the business so that you can be assured that the products we install in your home will be reliable and long lasting. We want to work with you to find a solution that will best fit both your home and your budget!

Services Provided by TerraFirma in King County, WA 

  • Basement waterproofing
  • Crawl space repair
  • Sump pumps

If you want to get started on your home's basement waterproofing project, call TerraFirma in King County, WA for a free estimate today!

News & Events From from King County
How water damage affects your foundation
Along with the potential of mold growing in your basement or crawl space, water damage could also affect your foundation.... [Read more]
How your crawl space affects your heating bill
Keeping your home warm and comfortable can get a little pricey during the winter, but there is a way for you to reduce your monthly energy bill.... [Read more]
Heavy storm to hit Oregon and SW Washington tonight
According to the National Weather Service, the strongest storm of winter is expected to hit Oregon and Washington tonight.... [Read more]
Work Requests From King County, WA
Vicinity of in King
Void below the basement slab
Serving the following King County, WA zip codes
Seattle 98106, Seattle 98155, Seattle 98139, Seattle 98127, Seattle 98194, Seattle 98118, Seattle 98177, Seattle 98111, Seattle 98164, Seattle 98103, Seattle 98146, Seattle 98134, Seattle 98124, Seattle 98188, Seattle 98115, Seattle 98170, Seattle 98107, Seattle 98158, Seattle 98141, Seattle 98129, Seattle 98195, Seattle 98119, Seattle 98178, Seattle 98112, Seattle 98165, Seattle 98104, Seattle 98148, Seattle 98136, Seattle 98125, Seattle 98190, Seattle 98116, Seattle 98174, Seattle 98108, Seattle 98160, Seattle 98101, Seattle 98144, Seattle 98131, Seattle 98198, Seattle 98121, Seattle 98181, Seattle 98113, Seattle 98166, Seattle 98105, Seattle 98154, Seattle 98138, Seattle 98126, Seattle 98191, Seattle 98117, Seattle 98175, Seattle 98109, Seattle 98161, Seattle 98102, Seattle 98145, Seattle 98133, Seattle 98199, Seattle 98122, Seattle 98185, Seattle 98114, Seattle 98168, Bellevue 98005, Bellevue 98009, Bellevue 98006, Bellevue 98015, Bellevue 98007, Bellevue 98004, Bellevue 98008, Kent 98042, Kent 98030, Kent 98031, Kent 98035, Kent 98032, Kent 98089, Kent 98064, Renton 98059, Renton 98056, Renton 98057, Renton 98058, Renton 98055, Federal Way 98093, Federal Way 98023, Federal Way 98003, Federal Way 98063, Kirkland 98033, Kirkland 98034, Kirkland 98083, Auburn 98001, Auburn 98092, Auburn 98002, Auburn 98071, Redmond 98073, Redmond 98052, Redmond 98053, Sammamish 98074, Sammamish 98075, Bothell 98041, Bothell 98011, Issaquah 98027, Issaquah 98029, Maple Valley 98038, Mercer Island 98040, Kenmore 98028, Snoqualmie 98065, Woodinville 98072, Woodinville 98077, Enumclaw 98022, Vashon 98070, Duvall 98019, Pacific 98047, North Bend 98045, Fall City 98024, Black Diamond 98010, Ravensdale 98051, Medina 98039, Carnation 98014, Preston 98050, Baring 98224, Skykomish 98288, Hobart 98025, Burton 98013, Seahurst 98062