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    Average homeowner rating
  • Verified reviews icon10
    Verified basement waterproofing services reviews

Find Basement waterproofing pros in Union

Avatar for TerraFirma
TerraFirma
4.0(
100
)
Foundation, Basement or Crawlspace - Waterproofing / EncapsulationBasement Drainage Channels - RepairBasement Drainage Channels - Install

Serving Union, 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%
101 neighbors recently requested a quote
Avatar for Harts Plumbers, Electricians, & HVAC Technicians
Harts Plumbers, Electricians, & HVAC Technicians
4.6(
1,463
)
Basement Drainage Channels - InstallBasement Drainage Channels - Repair

Serving Union, WA and surrounding areas

Approved

Super Service Award Winner

In business since 2013

Emergency services offered

Warranties offered

"This company is so professional and kind. Anthony, the rep who came to do the estimate on a basement kitchen sink and shower installation was so knowledgeable. and patient, My elderly mother has moved in and is making our finished basement her new home, he addressed all her concerns and helped to make some smart choices. Lexi, the phone coordinator was lovely as well."
Prep Area
Waterfall Finished!
Excavation jobs and more!
 install grease trap for commercial kitchen
Delivery of Shoring

+334

56 neighbors recently requested a quote
Recommended by86%of homeowners
Avatar for Pinpoint Construction LLC
Pinpoint Construction LLC
5.0(
7
)
Basement Drainage Channels - Install

Serving Union, WA and surrounding areas

Approved

Super Service Award Winner

In business since 2024

Free estimates

Credit card accepted

"I had a great experience with this team; they were skilled and professional throughout the excavation and grading process. Their attention to detail and reliable service left me feeling confident and fully satisfied, so I would definitely recommend them to anyone needing quality work and exceptional service."
Gravel driveway
Ruts in the driveway which causing the water to run down the driveway?
Well utility trench
Gravel driveway
Driveway work in North Kitsap

+15

1 neighbors recently requested a quote
Recommended by50%of homeowners
Avatar for BUILDING PERFORMANCE PROS LLC
BUILDING PERFORMANCE PROS LLC
4.5(
8
)
Foundation, Basement or Crawlspace - Waterproofing / Encapsulation

Serving Union, WA and surrounding areas

Approved

In business since 2025

Free estimates

Credit card accepted

"The workers were on time. Very efficient. They did a blower door test and found the air leaks and insulated these areas. Blew installation above the garage, cleaned out the crawl space and put new installation there and basement. Found a water leak from my toilet,Thank goodness. Covered everything in the basement and swept and cleaned up after. I would recommend them!"
Response time2 days
9 neighbors recently requested a quote
Avatar for KLC EXCAVATING LLC
KLC EXCAVATING LLC
5.0(
6
)
Basement Drainage Channels - Install

Serving Union, WA and surrounding areas

Approved

Free estimates

Credit card accepted

Offers commercial services

"Great company to work with. He was professional, reliable, and communicated well throughout the project. The work was finished on time, and the quality was better than I expected. I’d definitely recommend him to anyone needing excavation or landscaping work, and I would happily use him again in the future."
Stump Removal
Stump Removal
Stump Removal
Stump Removal
1 neighbors recently requested a quote
Avatar for Diversified Crawlspace Servs
Diversified Crawlspace Servs
3.9(
25
)
Foundation, Basement or Crawlspace - Waterproofing / Encapsulation

Serving Union, WA and surrounding areas

Approved

In business since 1992

Free estimates

Emergency services offered

"We had a foot of water in our crawl space after the snow and 6 in. of rain from the December 2021 storms. I had called several companies to come out to take a look and give quotes. Ethan from diversified was the 3rd quote we received. Ethan explained the issue, explained what they would do to remedy it, and answered all my questions. He sent me the quote which was very resonable. BE SURE TO GET SEVERAL QUOTES. ONE COMPANY QUOTED US DOUBLE OF WHAT WE PAID DIVERSIFIED. They were able to get a team out two days later. The team was on time, professional, and did really good work. We ended up needing a sump pump due to ground water coming up. They applied a mold application and completed the work in a day. I highly recommend these guys and did my research prior to having them do the work. I am very impressed and happy we chose them."
crawlspace drainage
crawlspace drainage
crawlspace drainage
crawlspace drainage
crawlspace drainage

+18

7 neighbors recently requested a quote
Recommended by60%of homeowners
Avatar for TH Excavation LLC
TH Excavation LLC
5.0(
2
)
Basement Drainage Channels - Install

Serving Union, WA and surrounding areas

Approved

In business since 2023

Free estimates

Emergency services offered

"10/10 would recommend to anyone. Came in with a great attitude and was more than accommodating to my needs. Excellent customer service and I no longer experience any flooding! THANK YOU TH EXCAVATION"
Hole under foundation where water was coming in.
Grading
Before
Broken tee fitting
Side of house before we started working.

+27

3 neighbors recently requested a quote
Recommended by50%of homeowners
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Basement Waterproofing questions, answered by experts

Basements are commonly converted into game rooms. The potential challenges you may run into include controlling moisture, working with low ceilings, limited natural light, and the need for additional electrical or HVAC work. Addressing these issues can add to the total cost, but it ensures a comfortable and functional space.

You should take care of any sign of water in your basement, whether it’s dampness after heavy rain or puddles of water on the floor. Besides potentially causing a health hazard, the moisture can damage your home’s structure and foundation. Furthermore, mold can grow quickly and spread throughout the rest of your home. With mold remediation costs ranging between $1,200 and $3,400, it’s best to avoid mold issues by fixing the leak.

Whether to waterproof your basement from the interior or exterior depends on several factors, including your budget.

Exterior waterproofing is generally considered the superior method because it stops water at the source, preventing it from seeping into and damaging your basement walls. This approach offers the most protection, making it ideal if you use your basement for storage.

By contrast, interior waterproofing is often less expensive and requires less labor because the area is more accessible.

For maximum protection against water leakage and moisture, applying waterproofing measures to both the inside and outside is the best solution. However, if you must choose only one, stopping water from the outside is the most effective approach to preserve your foundation and prevent damage.

Basements with persistent moisture problems or flooding shouldn’t be finished until the moisture issues have been fixed. In addition, if your foundation is cracked, you have unmitigated radon levels, or you have asbestos or lead pipes, remediate the underlying problem before finishing your basement. Turning a basement into living space before fixing these issues can lead to serious health risks or structural damage. 

A sump pump can remove excess moisture from under a house if standing water is present. Other ways to protect your crawl space from moisture include installing a vapor barrier, using a dehumidifier, installing insulation, and using a fan to dry the space. Finally, keeping your gutters clear of debris and positioning your downspouts away from the home’s foundation can prevent moisture from getting into the crawl space in the first place.

The Union, WA homeowners’ guide to basement waterproofing services

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