Basement Waterproofing in Thornhill

It depends on how much of the wall is involved, with a single injected crack starting around $400. An interior drainage system along the inside of the footing is priced at $100 to $250 for every linear foot treated, and digging out the exterior to membrane the wall is $250 to $450 for every linear foot. On most Thornhill houses the diagnosis points to one or two walls rather than all four, and the written quote prices only those.

Neither is better in general, because they answer different faults. Working from outside wraps the wall in a membrane and gives the water a drained route away, which is the fuller answer when clay backfill is holding water against the foundation, but it means digging up the side yard and whatever is planted in it. An inside system intercepts water after it has come through, costs less, and leaves the garden alone, and we tell you which fault your house actually has before recommending either.

Sealing a single crack by injection normally takes a few hours. An interior drainage run takes one to two days, and an exterior dig on a Thornhill house takes three to five working days, longer where a driveway, a deck, or a side yard fence has to come out first. You get that working estimate in writing before we start, so the timeline does not shift halfway through.

Yes. The condo and office buildings clustered around Commerce Valley and along Highway 7 sit over underground garages, and we work on their traffic bearing membranes, expansion joints, and leaking cracks in the slabs and walls. Because a condo board has to approve the spending before anything happens, our reports are written for a reserve fund study rather than for a homeowner.

A written one, tied to the specific system we install and given to you before the job starts. A crack injection, an interior drainage run, and an exterior membrane are each covered on different terms, and we walk through the limits of each with you at quoting so there is nothing to discover later.

Foundation cracks that have opened as backfill settled, window wells without functioning drains, and grading that has shifted toward the house over three decades so that surface water now arrives at the wall. The last two are cheap to fix and are checked before anybody talks about a system.

On 1980s and 90s construction it is usually perforated plastic rather than clay, which is better news than owners of older housing get, but it is still thirty years into a life spent surrounded by settling backfill and tree roots. It can be scoped by camera where there is an accessible cleanout. What we typically find is partial blockage from silt or root intrusion rather than outright collapse, and that matters because a system relying on a compromised line will underperform no matter how well it is installed.

It is the first thing we look at and one of the most frequent findings, because a downspout emptying within a foot or two of the wall delivers the entire roof volume to the foundation during every storm, exactly the load the drainage was meant to be spared. Extending the discharge well clear of the building, and confirming it is not simply running back along settled grading, is inexpensive and occasionally resolves the problem outright. Where a downspout has been tied directly into the drainage line, disconnecting it is the priority.

If the recommendation is an interior system then yes, because an interior system works by collecting water and discharging it, which requires a pump. The failure mode worth planning for is that storms and power interruptions arrive together, so on a finished basement we specify battery backup or a water powered secondary as a matter of course. A pump with no redundancy protecting a finished lower level is a single point of failure in the exact conditions it exists for.

It depends on the system and we tell you before the work rather than after. Transfer terms are not the same for an injected crack, an inside drainage system, and an outside membrane, and they matter at resale, because a buyer's lawyer will usually ask whether the below grade work comes with paperwork the new owner can rely on. We hand over the written terms and the completion documentation together so the file is complete if the house changes hands.