This guide compares 23 waterproofing companies serving Ottawa. The featured shortlist includes Summit Drain & Plumbing, Wet Basement Solutions, and The Foundation Experts Inc.. Listings claimed by their owner appear first; all other positions follow the published rating methodology. 22 carry a sourced public rating, averaging 4.8 stars; the highest-rated is D'Agui Masonry Ottawa at 5.0 stars from 215 Google reviews.
A wet or leaky basement in Ottawa is common, thanks to clay soil and a hard freeze-thaw cycle, and the fix depends entirely on finding the real source of the water first. The best waterproofing companies diagnose before they seal, whether the cause is grading, weeping tile, or a cracked foundation, and they warranty the result. The companies below handle wet and leaky basements: interior and exterior waterproofing, foundation crack repair, sump pumps, and drainage across the city. Each is a real Ottawa business with public reviews you can read, so you can compare diagnosis, methods, and warranty before you spend on a fix that has to actually keep water out.
Also covers: Wet basement · Leaky basement · Foundation crack repair · Sump pumps · Drainage
Featured professionals
A focused Ottawa shortlist. Listings claimed by their owner appear first; all other positions follow our published rating methodology.
Listings claimed by their owner appear first. All other positions follow the selected sort.
FeaturedKanata
5.0(127)on GoogleChecked Aug 2026Basement WaterproofingKanata-based waterproofing and plumbing company (BBB A+) handling foundation waterproofing, weeping tile, sump pumps and drain/sewer work. Offers 24/7 emergency service.
View Summit Drain & Plumbing
FeaturedClaimedKanata +7
5.0(126)on GoogleChecked Aug 2026Basement WaterproofingWaterproofing and foundation-repair company established in 2008, based in Carleton Place and serving the Ottawa Valley and Eastern Ontario. Offers a lifetime warranty and free quotes.
View Wet Basement Solutions
Orléans +3
5.0(27)on GoogleChecked Jul 2026Basement WaterproofingOttawa foundation-repair and waterproofing company operating since 1995 and BBB A+ accredited. Offers a 25-year transferable warranty on waterproofing work.
View The Foundation Experts Inc.More basement waterproofing
Ardel Concrete Services is a concrete contractor in Ottawa. Rated 4.9 from 38 Google reviews.
View Ardel Concrete Services
FeaturedBraden Foundation Construction is a waterproofing service in Ottawa offering concrete work and drainage. Rated 5 from 105 Google reviews.
View Braden Foundation Construction
Nepean
4.8(124)on GoogleChecked Aug 2026Concrete & MasonryColiseum Concrete & Interlock is a concrete contractor in Nepean, Ottawa. Rated 4.8 from 124 Google reviews.
View Coliseum Concrete & Interlock
FeaturedD'Agui Masonry Ottawa is a masonry contractor in Ottawa. Rated 5 from 214 Google reviews.
View D'Agui Masonry Ottawa
Donovan Complete Masonry is a masonry contractor in Ottawa offering chimney sweeping. Rated 4.8 from 54 Google reviews.
View Donovan Complete Masonry
Barrhaven +4
4.9(70)on GoogleChecked Aug 2026PlumbersDr. Pipe Drain and Plumbing is a plumber in Ottawa offering bathroom renovation, drainage and hot water systems. Rated 4.9 from 70 Google reviews.
View Dr. Pipe Drain and Plumbing
FeaturedEC Foundations is a concrete contractor in Ottawa offering waterproofing. Rated 4.9 from 60 Google reviews.
View EC FoundationsBarrhaven +8
5.0(13)on GoogleChecked Aug 2026Basement WaterproofingJust Foundations is a waterproofing service in Ottawa. Rated 5 from 13 Google reviews.
View Just Foundations
Barrhaven +8
5.0(23)on GoogleChecked Aug 2026Concrete & MasonryKavanagh Masonry is a masonry contractor in Stittsville, Ottawa. Rated 5 from 23 Google reviews.
View Kavanagh Masonry
Nepean
4.9(48)on GoogleChecked Aug 2026FencingMedusa Stoneworks is a fence contractor in Nepean, Ottawa offering concrete work and landscape design. Rated 4.9 from 48 Google reviews.
View Medusa Stoneworks
Gloucester +3
4.4(82)on GoogleChecked Aug 2026Basement WaterproofingOttawa foundation and waterproofing contractor operating since 1992, offering a 10-year transferable written warranty. Handles basement waterproofing, foundation crack and structural repair, and crawl space encapsulation.
View Mr. Foundation Inc.
Ottawa Foundation Repair is a waterproofing service in Ottawa offering concrete work and septic systems. Rated 4.8 from 98 Google reviews.
View Ottawa Foundation Repair
Ottawa Masonry & Parging Contractors is a masonry contractor in Ottawa offering building restoration. Rated 5 from 82 Google reviews.
View Ottawa Masonry & Parging Contractors
Nepean
4.1(23)on GoogleChecked Aug 2026Basement WaterproofingOttawa Structural Residential Services Ltd is a foundation in Nepean, Ottawa offering waterproofing. Rated 4.1 from 23 Google reviews.
View Ottawa Structural Residential Services Ltd
Kanata +7
5.0(15)on GoogleChecked Aug 2026Basement WaterproofingFoundation repair and waterproofing company serving Ottawa, Gatineau and Kingston. Covers interior and exterior waterproofing, crack repair, weeping tile and flooded-basement solutions.
View Pro-Core Foundations
Solid Masonry is a masonry contractor in North Gower, Ottawa. Rated 5 from 29 Google reviews.
View Solid Masonry
FeaturedStonehenge Masonry is a masonry contractor in Ottawa. Rated 4.9 from 131 Google reviews.
View Stonehenge Masonry
Nepean +4
4.3(208)on GoogleChecked Aug 2026Basement WaterproofingLong-running basement waterproofing and foundation-repair firm serving the greater Ottawa region since 1978. Offers a transferable lifetime dry-basement warranty.
View The Foundation Guys Inc.
Gloucester
4.9(56)on GoogleChecked Aug 2026Basement WaterproofingTirenio Parging is a concrete contractor in Gloucester, Ottawa offering masonry. Rated 4.9 from 56 Google reviews.
View Tirenio Parging
Nepean +2
Basement WaterproofingOttawa-area waterproofing company covering interior and exterior basement waterproofing, weeping tile, sump pumps and backwater valves. Provides a 3-year labour warranty and free online quotes.
View iBasementsBuyer guide
What separates a great waterproofing company from a cheap quote, and the questions worth asking before you sign.
Sealing a wall without finding the source often just moves the leak. A good contractor traces whether it is grading, weeping tile, or a crack before quoting a fix.
Interior systems manage water that gets in; exterior excavation stops it at the wall. They solve different problems at very different costs. Ask which your situation actually needs.
Ottawa's spring melt tests every sump pump. Ask about a battery or water-powered backup so it keeps running through a storm outage.
Waterproofing should come with a transferable warranty. Confirm its length and exactly what it covers, since a dry basement is the whole point.
Common questions
Basement Waterproofing by area
For homeowners
Tell us about the job and we will suggest up to three Ottawa waterproofing companies based on the service and area you select.