Top-rated basement waterproofing pros.

Get matched with top basement waterproofing pros in Cornelius, OR

Enter your zip and get matched with up to 5 pros

Need a pro for your basement waterproofing project in Cornelius, OR?

Select your specific project to find the pro for you.

TRUSTED BY CORNELIUS, OR HOMEOWNERS

  • Average homeowner rating star icon4.2
    Average homeowner rating
  • Verified reviews icon66
    Verified basement waterproofing services reviews

Verified Reviews for Basement Waterproofing pros in Cornelius, OR

*The Angi rating for Basement Waterproofing companies in Cornelius, OR is a rating based on verified reviews from our community of homeowners who have used these pros to meet their Basement Waterproofing needs.

*The HomeAdvisor rating for Basement Waterproofing companies in Cornelius, OR is a rating based on verified reviews from our community of homeowners who have used these pros to meet their Basement Waterproofing needs.

Last update on August 24, 2025

Find Basement waterproofing pros in Cornelius

Avatar for John's Waterproofing
John's Waterproofing
4.3(
252
)
Foundation, Basement or Crawlspace - Waterproofing / EncapsulationBasement Drainage Channels - InstallBasement Drainage Channels - Repair

Serving Cornelius, OR and surrounding areas

Approved

In business since 1974

Free estimates

Warranties offered

"From the first visit to my home from Sean for an estimate, to the crew that arrived to do the project I was impressed. Everyone was extremely professional. The crew arrived on time, the crew leader introduced me to the rest of the crew and explained how they would proceed with the project. They protected the work spaces with plastic from my garage to the crawl space opening in side my closet. They went to work and kept me informed about the progress. The whole crew worked very efficiently and got the project done in one day. They left work area spotless when they were done. I would highly recommend this company for any waterproofing project!!"
Trim around fireplace was removed and mold found along the base
Fiberglass was drooping away from the home, removing its insulation value
Fiberglass Insulation was falling down in clumps from water weight
This window had been upgraded and given trim to give a clean and finished look
Re removed the below-grade sections of the wall and waterproofed with ThermalDry Radiant vapor barrier and installed a drain system around the interior perimeter

+41

Response time9 hrs
Response rate100%
22 neighbors recently requested a quote
Request Quote
Avatar for Better Basements and Waterproofing
Better Basements and Waterproofing
5.0(
10
)
Foundation, Basement or Crawlspace - Waterproofing / Encapsulation

Serving Cornelius, OR and surrounding areas

Approved

In business since 2022

Free estimates

Credit card accepted

"Dylan Milroy went in and cleaned out the crawlspace put down plastic and dug a french drain and redirected all the downspouts so that the rain and we had now more water being drained. He is super easy to work honest he follows up to see if you are satisfied with his work.. I recommend him to everyone."
12mil vapor barrier
12mil vapor barrier
Standard Vapor Barrier
Exterior Drainage
Exterior Drainage

+3

3 neighbors recently requested a quote
Recommended by50%of homeowners
Request Quote
Avatar for Groundworks
Groundworks
4.6(
915
)
Basement Drainage Channels - InstallBasement Drainage Channels - RepairFoundation, Basement or Crawlspace - Waterproofing / Encapsulation

Serving Cornelius, OR and surrounding areas

Approved (Corporate)

In business since 2021

Free estimates

Warranties offered

Groundworks is the North America's leading and fastest-growing foundation repair and water management solutions provider. Groundworks is a vertically integrated company with its own manufacturing operations and a world-class software solution, allowing us to serve our customers more effectively. From the first phone call to the annual maintenance offered, our customers have peace of mind knowing we're there with one mission to repair, protect and improve their home. For state licenses visit Groundworks.com/licensing

Basement
Basement
Basement
Concrete
Concrete

+20

Recommended by93%of homeowners
Request Quote
Avatar for John's Waterproofing Co.
John's Waterproofing Co.
4.0(
72
)
Foundation, Basement or Crawlspace - Waterproofing / Encapsulation

Serving Cornelius, OR and surrounding areas

Approved

In business since 1974

Free estimates

Warranties offered

"Friends who know what our basement looked like before are flabbergasted. The information they send you after you contact them is super educational and everyone was prompt, polite, and professional. Wish we'd done this sooner."
Encapsulation System
Before Encapsulation
Before Interior Drain System
After Interior Drain System
Finished basement

+38

Response time6 hrs
217 neighbors recently requested a quote
Recommended by93%of homeowners
Request Quote
Avatar for Pacific Waterproofing & Foundation Solutions, LLC
Pacific Waterproofing & Foundation Solutions, LLC
4.9(
8
)
Foundation, Basement or Crawlspace - Waterproofing / EncapsulationBasement Drainage Channels - InstallBasement Drainage Channels - Repair

Serving Cornelius, OR and surrounding areas

Approved

In business since 2012

Free estimates

Warranties offered

"Very impressed with Darren: his work ethic, thoroughness of the work, cleanliness of the job site when the job was finished. He arrived when he said he would and stopped by when he was done for the day to let me know he was leaving. I certainly would recommend Pacific Waterproofing, LLC."
Response time2 days
7 neighbors recently requested a quote
Recommended by83%of homeowners
Request Quote
Avatar for Crawlspace Masters, Inc.
Crawlspace Masters, Inc.
4.9(
94
)
Foundation, Basement or Crawlspace - Waterproofing / EncapsulationBasement Drainage Channels - InstallBasement Drainage Channels - Repair

Serving Cornelius, OR and surrounding areas

Approved

In business since 2012

Free estimates

Emergency services offered

"They did a great job adding insulation to my attic. Quick and at a great price."
After
After
After
After
After

+221

Response time2 days
Response rate95%
50 neighbors recently requested a quote
Request Quote
Avatar for TerraFirma
TerraFirma
4.1(
100
)
Foundation, Basement or Crawlspace - Waterproofing / EncapsulationBasement Drainage Channels - InstallBasement Drainage Channels - Repair

Serving Cornelius, OR and surrounding areas

Approved

In business since 2005

Free estimates

Warranties offered

"The problem ended up being plumbing and not waterproofing. But TerraFirma did a consult right away, diagnosed the issue quickly and was really helpful in figuring out the next steps. I really appreciate their time."
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 time10 mins
Response rate100%
109 neighbors recently requested a quote
Request Quote
Avatar for D & F Plumbing, Heating and Cooling
D & F Plumbing, Heating and Cooling
4.2(
513
)
Basement Drainage Channels - InstallBasement Drainage Channels - Repair

Serving Cornelius, OR and surrounding areas

Approved (Corporate)

In business since 1927

Emergency services offered

Warranties offered

"Just fine, The whole line needs replacing from basement through to street. Will begin work in about a week or so."
Additional Photos
Additional Photos
Additional Photos
Additional Photos
Additional Photos

+18

3 neighbors recently requested a quote
Recommended by79%of homeowners
Request Quote
Avatar for Legacy Plumbing and Excavation, LLC
Legacy Plumbing and Excavation, LLC
4.5(
76
)
Basement Drainage Channels - Install

Serving Cornelius, OR and surrounding areas

Approved

Super Service Award Winner

In business since 2023

Free estimates

Emergency services offered

"James from Legacy Plumbing and Escavation was professional and friendly did an a awesome job in a timely manner in repairing a leaky shower in a home we had just purchased. Highly reccomend James and Legacy Plumbing and Escavation 🤙"
Sewer Repair
Excavation & Sewer
Response time9 hrs
Response rate95%
802 neighbors recently requested a quote
Request Quote
Avatar for 3 Mountains Plumbing
3 Mountains Plumbing
4.2(
648
)
Basement Drainage Channels - InstallBasement Drainage Channels - Repair

Serving Cornelius, OR and surrounding areas

Approved

In business since 2000

Emergency services offered

Warranties offered

"Did a great job. Cleared kitchen drain. Just moved here and little surprised they want to add on scoping and stuff. Maybe older house, but stuck with clear and he snaked it."
The 3MP Team (Circa 2017)
Bill Kerrigan
Alex Grabbing a Photo
Rolling Through Lake Oswego
Random Patch Photo

+103

Response time1 day
Recommended by92%of homeowners
Request Quote
...
Showing 1-10 of 86
Basement Waterproofing questions, answered by experts

Installing a bathroom in a basement isn’t a project for most homeowners. Many parts—plumbing, electricity, and carpentry—go into this project, each requiring expert-level knowledge and tools. One miscalculation can lead to very expensive repairs. Plus, some homeowner’s insurance might not pay for damages caused by a homeowner DIYing this project. You can protect yourself by allowing the pros to complete this job for you. 

While "dry" mode on your AC can help reduce humidity levels to some extent, it may not be as effective as a dedicated dehumidifier, especially in areas with extremely high humidity or larger spaces. Dehumidifiers are specifically designed to remove moisture from the air more efficiently, making them a better choice for tackling persistent humidity issues.

Yes, if your crawl space is prone to humidity, a dehumidifier can help keep it dry. For use in a crawl space, you’ll need a high-capacity and high-efficiency dehumidifier with built-in air filtration. It’s also wise to purchase one with a self-draining feature. Otherwise, you’ll need to climb into the crawl space to empty the dehumidifier.

Preventing water accumulation involves regular inspections, maintaining effective drainage systems, ensuring proper roof maintenance, and taking preventive measures against heavy rainfall or floods.

If foundation problems are not fixed, they will likely worsen over time, leading to more complex and expensive repairs. Neglecting a damaged foundation can cause a range of issues, including:

  • Structural Damage: Minor problems like small cracks can escalate into major structural issues. This can damage the house above the foundation and, in severe cases, lead to foundation walls caving in or a total collapse.

  • Water Damage and Pests: Moisture and water intrusion can cause flooding, mold growth, and pest infestations.

  • Health and Safety Risks: Mold can lead to poor indoor air quality and other health risks, while structural instability poses a significant safety hazard.

  • Reduced Home Efficiency: A compromised foundation can negatively impact your home's energy efficiency.

To avoid these escalating problems and costs, it's best to hire a foundation repair company to address any issues as soon as you become aware of them. The earlier problems are discovered and fixed, the lower the repair cost will likely be.

The Cornelius, OR homeowners’ guide to basement waterproofing services

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

See all articles