Interior Basement Waterproofing in Ajax & Durham Region
Perimeter drainage, sump pump & vapour barrier systems installed from inside — no excavation. Typically $70–$150 per linear foot.
What an Interior Waterproofing System Does
An interior system doesn't try to stop water outside your foundation — it captures water at the point of entry and channels it away before it ever reaches your floor. We break a narrow trench around the inside perimeter of your basement, install perforated drainage pipe in washed stone, seal the wall with a vapour barrier, and direct everything to a sump pit where the pump discharges it safely away from your home.
- Interior perimeter drain — captures seepage at the wall-floor (cove) joint, the most common entry point
- Sump pit & pump — professionally sized for your home and local water table, with battery backup options
- Wall vapour barrier — seals damp walls, directs wall seepage into the drain, and resists mould growth
When Interior Waterproofing Is the Right Choice
- Water seeps in at the wall-floor joint or up through floor cracks
- Excavation isn't practical — decks, driveways, additions or mature landscaping sit against the foundation
- You want a dry basement without tearing up the yard
- You're finishing the basement and want guaranteed protection behind the new walls
- Budget matters — interior systems typically cost less than full exterior excavation
Honest guidance: if water is pouring through wall cracks or your exterior membrane has failed, an interior system manages the symptom but exterior waterproofing fixes the cause. We'll tell you which one your home actually needs — free.
Our Installation Process
- Free inspection & fixed quote. We trace the water source, measure the perimeter, and give you an exact fixed price.
- Prepare the space. We protect floors and belongings, then cut a clean trench around the interior perimeter.
- Install drainage. Perforated pipe goes in on washed stone, pitched to the sump pit. Walls get a sealed vapour barrier tied into the drain.
- Set the sump system. Pit, primary pump and optional battery backup are installed and tested under load.
- Restore & clean. Concrete is re-poured flush, the site is cleaned, and we walk you through the system and your lifetime transferable warranty.
Most installations take 1–3 days depending on basement size and layout. The work is contained indoors, so weather never delays us.
Typical Cost
Interior waterproofing typically runs $70–$150 per linear foot. For a typical Ajax home that usually means $3,500–$15,000 depending on perimeter length, sump configuration and whether a battery backup is included. Your free on-site inspection produces an exact fixed quote — the number we quote is the number you pay.
Interior Waterproofing FAQ
It manages water by giving it a controlled path out — which is exactly what keeps your basement dry. Water entering at the cove joint or through the floor is captured by the perimeter drain and pumped away before it can pool, damage finishes or feed mould. For most seepage problems, that's a complete and permanent solution.
Yes — when sized correctly. We size the drain, pit and pump for your home's perimeter and the local water table, not a generic template. Adding a battery backup means the system keeps working even if the storm knocks out your power.
Concrete cutting creates dust — we control it with barriers, dust extraction and daily cleanup. We protect your floors and belongings, re-pour the trench flush, and leave the basement broom-clean. Most homeowners are surprised how tidy the job site stays.
Absolutely — that's one of the best reasons to install one. The vapour barrier sits behind your new walls, and the drainage runs silently underneath. Many of our customers install the system specifically before finishing, so their renovation investment is protected.
Every interior waterproofing system we install carries our lifetime transferable warranty — if the system we installed ever lets water in, we come back and make it right. It transfers to the next homeowner, which is a genuine selling feature at resale.
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