Top-rated basement waterproofing pros.

Best basement waterproofing pros near Ontario, CA

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Top-Rated Basement waterproofing pros in Ontario - Updated Nov 2026

Avatar for Alpha Structural, Inc.
Alpha Structural, Inc.
4.6(
241
)
Foundation, Basement or Crawlspace - Waterproofing / EncapsulationBasement Drainage Channels - InstallBasement Drainage Channels - Repair

Serving Ontario, CA and surrounding areas

Approved (Corporate)

In business since 1992

Free estimates

Emergency services offered

"Dan was here this morning, showed him where water was leaking in over our slab and ruining the flooring in the master bedroom. He gave me the full range of possible remedies, from installing a eaves gutter on the roofline outside the bedroom to a full (very expensive) sealing of the entire exterior foundation. And actually recommended that we start with the gutter (which I can do myself) and then monitor the area next rainy season and see if that fixes the problem. No pressure to hire them or spend big $$, just good advice. Couldn't have asked for more. Highly recommended- this is real service!"
Basement Addition
Basement Expansion
Caisson Supported Retaining Wall
Cantilevered Deck Design Build
Deck Expansion and Slope Failure with Retaining Wall

+323

Response time10 hrs
Response rate100%
11 neighbors recently requested a quote
Avatar for Western Rooter & Plumbing
Western Rooter & Plumbing
4.8(
172
)
Basement Drainage Channels - Install

Serving Ontario, CA and surrounding areas

Approved

In business since 1981

Free estimates

Emergency services offered

"I returned home from a trip and found water all over my downstairs bathroom and adjoining shed. It was late afternoon and I called Western Rooter who agreed to come out first thing the next day, I had a pretty sleepless night. Rene showed up the next day and assessed the situation and started clean up. Tony soon joined him and the two worked all day until after dark and helped me with cleanup and putting things right. They explained to me what they were doing and why along the way. I felt they charged a fair price. I am so grateful for their service and highly recommend Western Rooter."
Ruben installs a new drainage system under a customers home. Working in a crawl space is rough, but we do what is needed.
Backing up? Got roots? Blast those roots out with a Hydro Jetter! We use a wart hog nozzle that combines controlled rotation with a unique 8 jet cutting configuration optimized for removing roots. It’s better with a jetter! Call us! We got this! ??
Sewer Line Camera
No drain clog too big or small, Western Rooter covers them all!
Justin clearing a Kitchen sink back-up after the Memorial holiday.
HALO 5 whole house water filtration system.

+542

Response time12 hrs
Response rate100%
10 neighbors recently requested a quote
Avatar for Groundworks
Groundworks
3.5(
176
)
Foundation, Basement or Crawlspace - Waterproofing / EncapsulationBasement Drainage Channels - InstallBasement Drainage Channels - Repair

Serving Ontario, CA and surrounding areas

Approved (Corporate)

In business since 1995

Free estimates

Warranties offered

"Their initial price was really high and I declined. But, when they were left with a crew stuck in my area due to a cancelled job, they were really willing to negotiate. The guys were good and did a good job. I'm really happy I had my slab lifted."
Foundation
Foundation
Foundation
Concrete
Concrete

+16

Response time11 hrs
95 neighbors recently requested a quote
Recommended by38%of homeowners
RSF Construction Inc.
1.0(
1
)
Basement Drainage Channels - InstallBasement Drainage Channels - RepairFoundation, Basement or Crawlspace - Waterproofing / Encapsulation

Serving Ontario, CA and surrounding areas

Approved

In business since 2019

Free estimates

Credit card accepted

RSF Construction Inc. is a leader in providing our customers with the highest quality service in an honest, efficient, and professional way. Our pledge is to create successful relationships with our customers, employees and community by building trust, treating every project with the utmost integrity and exceeding expectations. We look forward to working with you!

Palm Construction, Inc.
5.0(
112
)
Foundation, Basement or Crawlspace - Waterproofing / Encapsulation

Serving Ontario, CA and surrounding areas

In business since 2016

Free estimates

Credit card accepted

It can be a daunting task looking for not only the right contractor for your job but also the right contractor for you. We completely understand what you're going through. We know every customer has different desires, different needs and different schedules. We're not only here to turn your ideas into reality but to make it a memorable experience every step of the way. Call us right now, no matter where you are in the planning process.

Recommended by100%of homeowners
Palm Construction, Inc.
5.0(
90
)
Foundation, Basement or Crawlspace - Waterproofing / Encapsulation

Serving Ontario, CA and surrounding areas

In business since 2016

Free estimates

Credit card accepted

"We worked with Ali (sales manager) and Tony (project manager), who took the time to design a project that made sense for our property and our budget, made a number of suggestions and recommendations and were never pushy or tried to "sell" us on something. The crew really went above and beyond to provide top quality workmanship and overall we were in very good hands. Highly recommended!"
Recommended by100%of homeowners
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Basement Waterproofing FAQs, answered by experts

When considering finishing your basement, take into account a few pros and cons:

Pros

  • Can increase the value of your home

  • Separate space from the rest of the house 

  • Customize and personalize the basement to suit your needs and style

  • Increase the amount of living space in your home

Cons

  • May not regain enough value to cover the cost of finishing

  • Lack of natural light if it’s below ground level

  • Moisture or flooding can cause costly damage

  • Installing plumbing and electrical can be messy and costly

Rigid foam board insulation is one of the safest insulation materials for basement walls. The panels offer a moisture barrier to prevent mold and mildew build-up. At the same time, this material is also fire-resistant, so you don’t have to worry as much about a fire breaking out as you would with spray foam insulation. 

While it’s possible to seal a foundation yourself, it’s not recommended, as it’s a tricky and labor-intensive job. Foundation sealing is best left to the pros to save yourself time, remove the risk of doing it wrong, and keeping yourself safe. Call a foundation repair professional near you to see what the job will cost.

A sewage smell in your crawl space is usually from a damaged or clogged pipe leaking sewer gasses or actual sewage underneath your home, but there are some other common causes. Moisture, from poor or damaged encapsulation or a malfunctioning sump pump, can harbor mold and bacteria, causing a musty smell. Pests can also get stuck in your crawl space and die, which causes a sewage-like odor.

Yes, water and water vapor can seep through cracks in your basement floor, which means you should address all basement floor cracks, even if they don’t indicate structural issues. Sealing settling cracks and shrinkage cracks is a good idea to keep water and moisture outside where it belongs. Doing so can improve your indoor air quality, reduce the risk of mold growth, make your home more comfortable, and help prevent pest infestation.

The Ontario, CA homeowners’ guide to basement waterproofing services

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