Foundation and basement questions, answered

Many are. Poured concrete shrinks as it cures, so thin vertical cracks are common in homes of every age. They're worth fixing if they leak, keep getting wider, or run horizontally or in a stair-step pattern.

Mark both ends with a pencil, write the date beside it, and measure the widest point. Check again in two or three months. A crack that's longer or wider needs a professional look.

It's efflorescence: mineral salts left behind when water moves through concrete and evaporates. It isn't harmful in itself, but it tells you moisture is getting through the wall at that spot.

Usually high humidity or hidden moisture. Run a dehumidifier and aim to keep basement humidity around 50% or lower. If the smell stays, look for damp spots, efflorescence or water staining along the bottom of the walls.

Not always. Tape a square of plastic wrap to the wall for two days. Moisture under the plastic is coming through the wall. Moisture on top is condensation, which a dehumidifier fixes.

A leak is groundwater coming in through the walls, cracks or the floor edge. A sewer backup comes up through the floor drain, often during a big storm, and may smell. Backups are handled by a plumber (usually with a backwater valve) and the Region of Durham, not a foundation contractor.

Injecting a crack from inside generally doesn't need one. Structural repairs, underpinning, footing work and enlarging windows usually do, and a backwater valve usually needs a plumbing permit. Check with your town's building department or ask the contractor.

If you're within two years of taking possession, water getting in through the basement or foundation walls is covered by the Tarion new-home warranty in Ontario. Major structural defects are covered for seven years. Report it to your builder in writing first.

Usually not. Cracks from settlement or shrinkage and gradual seepage are generally excluded. Sudden water damage, sewer backup or overland flooding may be covered if you have those options. Call your insurer and take photos first.

Interior work, including crack injection and interior drainage, can be done year-round. Exterior digging is possible in winter but slower in frozen ground, so most exterior jobs happen from spring to late fall.

Not automatically. A dry vertical shrinkage crack is common and relatively inexpensive to fix if it ever leaks. Horizontal cracks, stair-step cracks, bowing walls or signs of past water are worth a specialist's look before you firm up the deal.

You tell us what you're seeing through the form. We review it, get back to you, and pass your details to a vetted, independent local foundation contractor who serves your town. They call you, assess the problem and give you a written quote. You deal with them directly and you're never obligated to hire them.

A qualified, independent local foundation contractor that meets our standards. They assess the problem, quote in writing, and do the work under their own name, insurance and warranty.

Yes, for homeowners. The contractor may pay us a referral fee. You never pay us anything.

We only refer a contractor that carries liability insurance, have WSIB coverage, give written quotes with a written warranty, and have a public track record of customer reviews.

Durham Region's lakeshore municipalities: Pickering, Ajax, Whitby (including Brooklin), Oshawa and Clarington (Bowmanville, Courtice and Newcastle).