Wet & leaking basements
Leaking basement repair in Durham Region
Water in the basement nearly always comes from one of a handful of places. Finding the right one is what makes the repair work, and keeps you from paying for the wrong fix.
Durham Crack Repair is a free referral service, not a contractor. Here's how we work.
Where the water is coming from
| What you see | Likely source | Usual fix |
|---|---|---|
| Water running from a line in the wall | Foundation crack | Crack injection from inside |
| Small wet spots in a row across the wall | Tie-rod holes left from the concrete forms | Seal or inject each tie-rod hole |
| Water along the bottom edge, where floor meets wall | Cove joint, from water pressure under and around the footing | Interior drainage (weeping tile and sump) or exterior waterproofing |
| Water under or around a basement window | Window well filling up, with a clogged or missing drain | Clear or install a window well drain, add a cover |
| Water coming up through the floor or a floor drain | High water table or a sewer backup | Sump pump, backwater valve, or a plumber for the drain |
| Damp patches in summer, no puddles | Condensation | Dehumidifier and ventilation |
What leaking basement repairs cost around Durham
| Repair | Typical cost (CAD, 2026) |
|---|---|
| Crack injection, per crack | $500 – $1,500 ($1,200 – $2,800 if actively leaking) |
| Window well drain, per window | $500 – $1,500 |
| Sump pump installation | $1,200 – $3,000 |
| Interior drainage (weeping tile and sump) | $3,000 – $10,000 |
| Exterior membrane, per linear foot | $100 – $300 |
| Full exterior excavation and waterproofing | $8,000 – $25,000 |
Ranges drawn from published Canadian and Toronto-area price guides (2026). These are general estimates, not quotes.
Things to check before you call anyone
- Gutters and downspouts: clear, and discharging at least 1.5–2 m from the foundation.
- Grading: soil and paving should slope away from the house, not toward it.
- Window wells: free of leaves, with gravel at the bottom and a drain that isn't blocked.
- Sump pump (if you have one): pour in a bucket of water and make sure it switches on.
- Photos: take pictures of where the water shows up, with a date. It helps the contractor diagnose the source.
If the water is still coming in after that, the source is most likely the wall itself, and that's what a foundation contractor assesses. Get matched with a contractor
Common questions
Why does my basement only leak in spring?
In March and April the ground thaws while snow melts and rain falls on soil that can't drain yet. Water builds up around the foundation and pushes through any weak point: cracks, tie-rod holes, the floor-wall joint. Heavy fall rain can do the same.
Is a damp basement wall the same as a leak?
Not always. Damp patches in summer are often condensation: warm, humid air meeting cool concrete. Tape a square of plastic wrap to the wall for a couple of days. Moisture under the plastic means it's coming through the wall. Moisture on top means condensation, and a dehumidifier helps.
What's the cheapest way to fix a leaking basement?
Start outside: clean the gutters, extend downspouts well away from the house, and slope soil away from the foundation. If the water comes through one crack, interior injection is far cheaper than excavation. Bigger or multiple-source problems need interior drainage or exterior waterproofing.
Should I fix the leak before finishing my basement?
Yes. Once drywall is up, leaks are harder to find and the repair costs more because finishes have to come off. Fix and test through one wet season if you can.
Does home insurance cover a leaking basement?
Gradual seepage through foundation cracks is usually excluded. Sudden water damage, sewer backup or overland flooding may be covered if you have those add-ons. Check your policy and take photos before any cleanup.
Tell us what you're seeing
Free, no obligation. We pass your details to one local foundation contractor who calls you back to book an assessment and give you a written quote.