Basement Waterproofing in Markham

Sealing one crack by injection starts around $400, an interior drainage system is $100 to $250 per linear foot, and digging out a wall to apply an exterior membrane is $250 to $450 per linear foot. Most Markham basements we open up need work on part of the perimeter rather than all of it, so the written quote is limited to the sections the diagnosis supports.

It was almost certainly damp proofed instead. The distinction is not pedantry: a damp proofing coating slows vapour and resists soil moisture, while waterproofing resists standing water under pressure. On Markham's slow draining ground the difference shows up around the second decade, which is precisely when these calls arrive.

Outside work puts a membrane on the wall itself and gives groundwater a drain to follow, which is the fuller fix when water under pressure is the cause, but it means digging through the side yard, the landscaping, and sometimes the driveway. Inside work catches water after it gets through the wall and carries it to a sump, costs less, and on a finished Markham basement means opening the drywall along that wall instead of the yard. The diagnosis shows which of those two problems you actually have, and that settles it.

Yes: crack injection, expansion joint systems, and traffic bearing deck membranes, for the newer towers on the Highway 7 corridor and for older Markham condo stock whose original membranes are at or beyond their service life. Every report is written to slot into a reserve fund study, since a condo board needs the case made on paper before it can approve the spending.

Injecting a crack from inside takes a few hours, and an interior perimeter system is one to two days of work. An exterior dig on a house takes three to five days, toward the longer end where a Cornell rear lane or a narrow side yard makes access tight, and you have that range in writing before we begin.

Before work starts you get the written diagnosis with dated photographs, the written estimate for the sections being treated, and a written warranty specific to the system going in. Coverage is not the same for crack injection, interior drainage, and exterior membrane work, so we go through what yours covers line by line instead of leaving the limits to be discovered the day you need them.

We dig down along the failing wall, clean the concrete back to a sound surface, seal the cracks and form tie holes, strip what remains of the original damp proofing, and put on a membrane built to resist water under hydrostatic pressure. With the wall open we check the weeping tile at the footing, then backfill so the ground slopes away from the house, which on Markham's slow draining soil gives water a route away from the wall instead of a place to sit. That exterior work is priced at $250 to $450 per linear foot, and only on the walls our diagnosis points to.

For the failures that let water in, yes: settlement cracks, leaking tie holes, cold joints, and deteriorated parging, with a single crack injection starting around $400. A wall that is bowing, a horizontal crack, or stepped cracking through block is a structural question before it is a waterproofing one, and we say so in writing and recommend a structural assessment before anybody seals over it. Sealing a crack that is still moving only moves the leak along the wall.

Spring is when Markham's slow draining ground is at its wettest, so a seasonal leak narrows the list without settling it: a crack, a tie hole, a window well with no working drain, grading that has sunk toward the house, or the original coating failing along a whole wall can all show up then, and each costs something very different to fix. Nobody can tell those apart over the phone, so we come out, and the visit produces a written diagnosis with dated photographs and a written estimate. If water is actively coming in, we treat the visit as an emergency and come out around the clock.