Exterior Waterproofing · Ottawa
Exterior foundation waterproofing in Ottawa
Korvex Construction waterproofs foundation walls from the outside across Ottawa and repairs basement leaks where the water comes through the wall. We dig along the wall, repair cracks from the outside, put a waterproofing layer on its outside face, renew the weeping tile at the footing where it has failed, then backfill and regrade so water runs away from the house. Book a free on-site estimate for a written quote.
- Waterproofing layer
- Weeping tile
- Clear stone
- Compacted backfill
- Dimpled membrane
Down the outside of a foundation wall, from the regraded surface to the footing.
- 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
What goes wrong
How water gets into a basement through the wall
Water reaches a basement wall from the soil around it. Rain and snowmelt that the yard sends toward the house soak into the backfill against the foundation, and the wall stays wet on its outside face. Where that face has cracks, open tie holes, a failed coating or a gap around a pipe, water works its way through and shows up inside as damp patches, white stains, or a leak after a storm or during the spring melt.
Most of Ottawa sits on Leda clay, a marine clay that holds water. Backfill against a house settles over the years, and a yard that once sloped away from the wall can end up sloping toward it. Downspouts that empty at the foundation and slabs tipped toward the house add to the water sitting against the concrete.
At the bottom of the wall, many houses have weeping tile: a perforated foundation drain beside the footing that collects water from the soil and carries it away. Over the years it can fill with silt, be crushed or be blocked by roots. When it stops working, water collects at the base of the wall, and the joint where the wall meets the footing is a common place for a leak to start.
Exterior waterproofing deals with that water on the soil side of the wall, before it reaches the concrete. The ground along the leaking wall is dug out to expose it. Cracks are repaired from the outside, the wall is cleaned, and a waterproofing layer goes onto its outside face. Where the weeping tile has failed, it is replaced in clear stone and led to an outlet. The trench is backfilled and compacted, and the surface is regraded so water runs away from the house.
The digging is what makes it a bigger job, and why we usually open only the walls where water gets in. Walkways, steps, slabs and garden beds along the wall come up first, and a deck or a tree close to the house changes how the trench is dug. While the ground is open, the French drain, the downspouts and the parging above grade can be dealt with in the same job, so nothing has to be dug up twice.
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.
What we build
Exterior foundation waterproofing: the work we take on
Basement leak repair from the outside
The wall dug out where the leak shows inside, the path the water takes found on the outside face, and that section repaired and sealed.
Crack repair from the outside
Cracks in the concrete opened up and repaired on the soil side of the wall, then covered by the waterproofing layer.
Waterproofing layer
A waterproofing layer applied to the cleaned outside face of the foundation wall, from the bottom of the dug section up to the finished grade.
Weeping tile replacement
A clogged, crushed or root-blocked foundation drain at the footing replaced, or a new one installed, in clear stone and led to an outlet planned for your lot.
Clearing what sits on top
Old slabs, walkways, sod and topsoil along the wall lifted and set aside before any digging, and planned back in once the wall is sealed.
French drain with it
Where the yard sends water toward the house, a shallow French drain carries surface water across the lot to an outlet chosen before digging.
Backfill, grading and the surface
The trench backfilled and compacted, the ground regraded away from the house, and a clear-stone strip over dimpled membrane, slabs or a walkway finished along the wall.
Related work
Drainage along the foundation
Two Korvex drainage jobs at the foundation wall: membrane and clear stone along the house, and a French drain across the lawn. After a basement leak, a homeowner wrote on Facebook: “We just had a major leak in our basement and they efficiently waterproofed the foundation and created a french drain with outstanding finish of layering gravel and pavement reconstruction.”
French drain, walkway and rear patio
A French drain across the lawn, membrane and clear stone along the house, then a slab walkway to a rear patio.
View projectReviews
What homeowners say about our exterior waterproofing work
Quoted as written on Facebook. All reviews
“Vlad and his coworkers are very hard working and professional with a realistic and fair pricing that cant beat any other company out there ! We just had a major leak in our basement and they efficiently waterproofed the foundation and created a french drain with outstanding finish of layering gravel and pavement reconstruction. They are the people to call for almost any kind of work on your house !! Thank you guys God Bless & Respekt!”
Gio Ivana Herrera · French drain after a basement leak
Related services
Often built together
Service areas
Exterior foundation waterproofing across the Ottawa area
Soil, lot grading rules and house age change from one part of Ottawa to the next. Here is what that means for this work in each area.
On request: Gloucester, Carp, Richmond, Russell, Embrun. To check your street, call or text 613-880-7679.
- OttawaClay 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.
- KanataGroundwater near the Carp River
The same study estimated groundwater at about 2 to 3 m down, rising and falling with the seasons. Low yards need a clear plan for where surface water goes.
- StittsvilleWetland and organic soils
Almost a third of the same area is organic deposits, the soft wet ground around the Goulbourn Wetland. Soft spots under patios and walls are dug out and replaced with compacted granular base.
- BarrhavenJock River floodplain
The Jock River through south Barrhaven has a mapped 100-year floodplain, and part of it north of the river was cut and filled in 2019–2020 for a new subdivision.
- NepeanMature trees and root zones
The City protects private trees 30 cm or wider at 1.3 m up in the urban area. Its critical root zone is 10 cm out per 1 cm of trunk, so a 30 cm tree reaches about 3 m.
- OrleansThick marine clay
Much of Orleans sits on thick, soft Champlain Sea clay, which loses strength when disturbed. Excavation stays tidy and the granular base is compacted in lifts.
- ManotickRideau River regulated areas
Structures, site grading and fill in floodplain or shoreline areas can need a Rideau Valley Conservation Authority permit. Its online map shows whether a property is regulated.
- Riverside SouthMarine clay soils
The community plan calls for tree planting standards suited to marine clay soils. Clay under a new yard holds water, so base depth and compaction are planned for it.
FAQ
What homeowners ask about exterior foundation waterproofing
What is exterior foundation waterproofing?
It is waterproofing done on the outside of the basement wall. The ground along the wall is dug out to expose it, the wall is cleaned and repaired, and a waterproofing layer goes onto its outside face, between the concrete and the soil. Drainage at the footing carries water from the soil to an outlet, the trench is backfilled and compacted, and the surface is regraded so water flows away from the foundation.
What is weeping tile, and can you replace it?
Weeping tile is the perforated foundation drain beside the footing that collects water from the soil around the basement and carries it away. Over time it can fill with silt, be crushed or be blocked by roots. Korvex replaces it from the outside, or installs it where a house has none: the trench is dug down to it, the new pipe goes in clear stone, and it is led to an outlet planned for your lot.
How is it different from a French drain?
A French drain on our site is a shallow trench in the yard with fabric, clean stone and pipe where the design calls for it. It collects surface water and carries it to an outlet. Exterior waterproofing is work on the foundation wall itself, and weeping tile is the drain at the bottom of that wall. They are often planned together: the French drain and the grading move surface water away, and the wall work stops it getting through.
Can you fix a leaking basement from the outside?
Yes, where the water comes in through the wall. We look at where the leak shows inside and at the yard outside, then dig along that part of the wall. Cracks are repaired from the soil side, the wall gets a waterproofing layer, and the weeping tile is renewed if it has failed. Fixing the grading and the downspouts at the same time takes away the water that was feeding the leak.
What does exterior waterproofing deal with?
Water that comes through the wall and down to the footing from the soil outside. Basement water can also come from window wells, from the floor, from plumbing or from a yard and downspouts sending water at the house, so Korvex looks at where the water actually enters before recommending anything, and the written quote says what the work addresses.
What about utilities, trees and steps along the wall?
Whoever digs requests locates through Ontario Dig Authority (formerly Ontario One Call), at least five business days ahead, and the service is free; private lines are the owner’s to have marked. The City protects private trees 30 cm or wider at 1.3 m up in the urban area, with a critical root zone of 10 cm out per 1 cm of trunk, which matters when a tree stands close to the house. Steps, slabs and walkways along the wall are planned for at the site visit.
Where should my downspouts and grading send water afterwards?
City of Ottawa guidance advises disconnecting downspouts from the sewer system or foundation drains and sending roof water to permeable areas about 3 metres from the foundation, never onto a neighbour’s lot or the sidewalk. Owners are expected to keep the grades from the lot’s original grading plan and keep swales open. The regrading after the work follows those limits.
How is exterior waterproofing priced?
By the length of wall to be opened, what has to come up and go back on top of it, how easily the trench can be dug, the repairs the wall needs, whether the weeping tile is replaced, and the drainage and grading that go with it. Korvex Construction sees the house and the yard in person anywhere in Ottawa and the suburbs, and the written price follows that visit.
Book a free exterior waterproofing estimate
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.