Exterior Waterproofing · Ottawa, ON
Foundation and basement waterproofing in central Ottawa
Korvex Construction waterproofs foundations from the outside for central Ottawa homes, from the Glebe, Sandy Hill and Old Ottawa South to Alta Vista. We dig along the wall that leaks, repair cracks, waterproof the wall, renew failed weeping tile and regrade so water moves away. The free on-site estimate comes first, and the written quote follows it.
- Waterproofing layer
- Weeping tile
- Clear stone
- Compacted backfill
- Dimpled membrane
The local picture
Exterior Waterproofing in central Ottawa
The Glebe, Sandy Hill and Old Ottawa South were mostly built up in the late 1800s and early 1900s, and some houses from that time stand on stone. The City’s heritage plan for Clemow Estate East in the Glebe describes one of its yellow-brick houses as having a stone foundation. Stone and lime mortar call for their own repair methods, so the site visit starts by finding out what your basement wall is made of.
Under most of the city lies Leda clay, a marine clay that holds water. Soil packed against a basement wall in clay stays wet long after a storm, and that water works into every crack and joint below grade. An exterior job takes the wet soil off the wall, seals and protects the wall, lays a drain at the footing and puts back a backfill that lets water reach that drain.
Stone foundations and the heritage districts
Sandy Hill, the Glebe, Old Ottawa South
Korvex Construction repairs basement leaks from the outside on central Ottawa streets: we excavate along the affected wall, repair cracks, waterproof the wall below grade, replace failed weeping tile and regrade the surface. Call 613-880-7679 or request the free on-site estimate, and the written quote follows the visit.
Some Sandy Hill streets lie inside heritage conservation districts, and their plans set rules for foundations. The Daly Avenue plan asks owners to keep and repair the original foundation material, to have stone foundations repointed by an experienced mason with a soft, lime-rich mortar matching the original, and it does not permit new coatings such as parging that change how the foundation looks.
The draft plan for the Russell Avenue–Range Road area adds two points that bear on a leak: ensure positive drainage away from every foundation wall, and have a structural engineer inspect a foundation with noticeable settlement. On a heritage house we plan the excavation, the footing drain and the regrading, leave the visible stone as the plan requires, and bring in an engineer before digging when the wall has moved.
The City’s checklist for a leaking basement
The City’s basement flooding guidance reads like a list for the outside of the house: seal cracks in the walls and foundation, slope the ground away from the foundation, redirect downspouts to permeable ground 3 metres from the wall, and clear snow back so meltwater cannot seep in through the walls. It also says foundation drains should not be connected to the sanitary sewer.
Most of that list is exterior work we do. Crack repair and waterproofing happen while the wall is exposed. New weeping tile goes in at the footing once we have traced where the old tile drained. The surface is then regraded, the parging above grade is patched where the dig disturbed it, and each downspout gets a route to open ground.
Rain Ready Ottawa and the downspout work
Rain Ready Ottawa is the City’s rebate program for rainwater projects in priority areas, the older parts of the city built before adequate stormwater management was common. Downspout redirection is one of the projects it names, and eligibility is checked by address on the City’s site. If your street qualifies, tell us at the visit, so the downspout part of the quote can be read against the program’s own conditions.
At the site visit
What we check on a lot in central Ottawa
- 01
What the basement wall is made of: stone, block or poured concrete.
- 02
Whether the house sits in a heritage conservation district, and what its plan says about foundations.
- 03
Where water shows inside: a crack, the joint between wall and floor, or a damp patch low on one wall.
- 04
Walkways, steps and slabs along the wall that would come up for the dig.
- 05
Where the old weeping tile drains, if it can be traced.
- 06
Any sign the wall has moved, which brings in an engineer first.
What we plan around
Local conditions in central Ottawa
Each point links to the public source it was checked against. At the site visit we check how it applies to your lot.
- Clay under most of the city
Leda clay underlies most of Ottawa and is sensitive to water and disturbance. Excavation, compaction and a granular base are sized for that soil.
How we build it
What exterior waterproofing involves
Every wall is different, so the drawing shows the parts most exterior jobs share. The order matters: the wall is repaired and sealed while it is open, the drain at the footing is renewed while the trench is down to it, and the ground goes back so it carries water away.
- Find where water enters
Stains, damp patches and the yard outside are read together, so the dig opens the wall where the water actually comes in.
- Locates first
Buried lines are located before any digging along the house.
- Repair, then seal
Cracks are repaired and the wall cleaned before the waterproofing layer goes on, all while the wall is exposed.
- Drain at the footing
The existing weeping tile is checked where the trench reaches it, and replaced where it is clogged, crushed or blocked by roots.
- Backfill that stays put
Backfill is compacted as it goes back, so the ground beside the wall does not sink into a dip.
- Weather
Frozen ground cannot be compacted properly, and coatings need temperatures above freezing, so on most Ottawa sites this is spring-to-fall work.
- Regraded surfaceShaped to fall away from the house, so rain and snowmelt run off.Graded to drain
- Compacted backfillPlaced back against the wall and compacted, so it does not settle toward the house.Compacted in layers
- Waterproofing layerOn the outside face of the wall, between the concrete and the soil.On the outside face
- Foundation wallExposed, cleaned, and cracks repaired from the outside before anything covers it.Cracks repaired outside
- Clear stoneAround the drain, so water from the soil reaches the pipe.Open and free-draining
- Weeping tile at the footingA perforated foundation drain led to an outlet planned for the lot.Led to an outlet
“Vlad and his crew installed my patio in 2 days. Did excellent work and vlad answered any and all questions I asked. I highly recommend Korvex Development for any job you may require.”
Joe Ayoub · Patio installed
“Did awesome work! had them repair a leany fence and they were on time, cheap and super professional”
Josh Cohen-Collier · Leaning fence repaired
FAQ
Exterior Waterproofing in central Ottawa: common questions
Our Sandy Hill house has a stone foundation. Can it be waterproofed from outside?
Often, yes, with the heritage rules in view. The buried part of the wall can be exposed, repaired, protected and drained, and the yard regraded so water moves off. If the house is in a heritage conservation district, its plan can limit what goes on the visible part of the foundation; the Daly Avenue plan, for one, does not permit parging that alters its look. We check the district and the wall at the site visit.
Has Korvex waterproofed a foundation after a basement leak?
Yes. In a Facebook review from August 2026, Gio Ivana Herrera writes that after a major basement leak the crew "efficiently waterproofed the foundation and created a french drain", finished with layered gravel and rebuilt paving. The review does not say which part of Ottawa the house is in.
Can you waterproof a basement from the outside on a narrow central lot?
Usually, yes. The dig runs along the wall that leaks, so access counts for more than lot width: how soil comes out, where it is stockpiled and what has to be lifted first, such as a walkway, steps or a patio. We plan that at the site visit and put the surface back as part of the job.
Can you regrade my yard if water sits near the house?
Yes, within the City of Ottawa rules. Owners are expected to keep the grades from the original grading plan and keep swales open. We check what applies to your property, then plan slope and drainage inside those limits so water moves away from the foundation.
Book a free exterior waterproofing estimate in central Ottawa
Tell us what you want built and send a few photos. We come out, look at what sits under the job, and give you the scope and the price in writing.