Wet basement? Foundation cracks? Musty smell? We stop water at the source and protect your family's health. Free inspection, same-day response, written workmanship warranty.
We see these warning signs constantly in Unionville, Cornell, Markville, Berczy Village, Cathedraltown and older Markham subdivisions — usually long before standing water shows up. We fix all of them.
Puddles, damp carpet, or that one corner that always smells off after a heavy Ontario downpour.
Common in older Markham foundations after years of freeze–thaw. Hairline today, five-figure repair in 5 years if ignored.
Efflorescence, peeling paint, bubbling drywall — typical of York Region homes built on heavy clay soil.
A real health risk for kids, seniors, and anyone with allergies or asthma in the home.
Hidden mold spores from a wet basement are linked to asthma attacks, chronic coughs, allergies and serious respiratory illness — especially in kids, seniors and anyone with a weak immune system. Every day you wait, it spreads further into your walls, insulation and air.
Interior, exterior, and everything in between. Honest recommendations — never the most expensive option, just the right one.
Permanent fixes for wet basements.
Learn more →Stop leaks from inside with interior drainage and membranes.
Learn more →Excavation, membrane, and weeping tile — the permanent fix.
Learn more →Crack repair, parging, and structural reinforcement.
Learn more →Fast diagnosis, clean fix, no upsells.
Learn more →Polyurethane and epoxy injection for foundation cracks.
Learn more →New pumps, battery backups, and sump pits done right.
Learn more →Find the source. Fix it for life. No more wet basement.
Learn more →Markham basements leak for very specific local reasons. Most homes across York Region — from the older bungalows in Milliken and Thornhill to the 80s and 90s subdivisions in Unionville, Markville and Bullock — are built on heavy clay soil, with weeping tile and dampproofing systems that simply weren't designed for today's storms. Here's what we see most often.
Most Markham subdivisions sit on dense clay that holds water against your foundation walls long after the rain stops. That hydrostatic pressure is what eventually pushes moisture through cracks, cold joints, and the wall–footing seam.
Ontario winters expand and contract concrete dozens of times each season. In homes built before 2000 — common in Cornell, Berczy Village, Cathedraltown and older Markham neighbourhoods — this is the #1 cause of new vertical foundation cracks each spring.
When April brings days of steady rain on top of frozen ground, water has nowhere to go but down along your foundation. We get our busiest call volumes the week after the first major spring thaw across Markham and Stouffville.
Original clay or perforated weeping tile from the 70s, 80s and early 90s is now well past its service life in most older Markham subdivisions. Once it clogs or collapses, water backs up against the footing and finds its way in.
If your home was built before the early 2000s in York Region, the foundation almost certainly has a thin asphalt 'dampproof' coating — not a real waterproof membrane. It's designed to slow moisture, not stop liquid water, and it fails quietly over time.
On a lot of Markham lots we visit, the real fix isn't inside the basement at all — it's regrading soil away from the foundation, extending downspouts, or rebuilding a failed window well. We'll tell you when that's all you actually need.
Where we work: We commonly help homeowners in Unionville, Cornell, Markville, Berczy Village, Cathedraltown, Box Grove, Milliken, Wismer, Thornhill, Bullock and surrounding older Markham neighbourhoods dealing with foundation seepage, wet basements after spring rain, and cracked foundation walls. We also serve Richmond Hill, Stouffville, Aurora, Vaughan and north Scarborough across York Region.
We're a small local team helping Markham homeowners deal with basement leaks, moisture, and foundation cracks before the damage gets worse. A lot of homes across York Region run into basement seepage after heavy Ontario spring rain and the freeze–thaw cycles older foundations were never built for. We focus on honest advice, practical repairs, and fast response times — without pressure or confusing sales talk.
After-inspection walkthrough in a Markham basement — explaining what we found and what it actually needs.
Customer stories below are illustrative composites of real situations we handle in Markham.
"We woke up to 3 inches of water in our finished basement after a spring storm. Their team was on site by 9am, found the wall crack the previous contractor missed, and fixed it in two days. Six months later through the wettest October in years — bone dry. We can finally trust our basement again."
"I was paying for asthma meds for my daughter for two years. Our pediatrician finally suggested checking for hidden mold. They opened the laundry room wall and found exactly what we feared. They fixed the foundation crack causing it. Three weeks later my daughter slept through the night for the first time in a year."
"Two other companies wanted $14k for interior systems. This team did a free inspection, told me the real fix was exterior on one wall for $11k, and warned me the others would just delay the problem. Five winters later — perfectly dry. Honest people doing honest work."
Tell us what you're seeing. We'll give honest first guidance over the phone — free.
We come out, diagnose the real source, and explain it in plain English.
No per-hour billing. No hidden fees. You know the price before we lift a shovel.
Workmanship backed by our written warranty.
Get a quick range with our basement waterproofing cost calculator — built for Markham homes specifically.
Try the cost calculator →Most jobs range from $400 for a single foundation crack injection up to $9,000–$17,000 for a full exterior wall. Interior perimeter systems run roughly $90–$130 per linear foot. Use our cost calculator for a quick estimate, or call us for a free written on-site quote.
Both. Interior basement waterproofing uses a perimeter drainage system tied to a sump pit. Exterior basement waterproofing involves excavating to the footing and applying a rubberized membrane plus new weeping tile. We recommend the right one for your situation, never just the more expensive one.
Same-day response across Markham, usually within 2–4 hours for emergencies.
Yes — a written workmanship warranty on our exterior waterproofing and crack repairs. It stays with the home if you sell.
Fully licensed, fully insured, and WSIB-covered. Documentation provided before work begins.
Yes. We're based in Markham and regularly serve Richmond Hill, Vaughan, Thornhill, Stouffville, Aurora, and north Scarborough.
Dampproofing (the asphalt coating on most pre-2000 homes) only slows surface moisture and fails within 10–15 years. Waterproofing uses a thick rubberized membrane designed to stop liquid water for 30+ years.
Interior work takes 1–3 days with minimal disruption. Exterior work involves excavation along one wall — we restore landscaping when done. We protect floors, walk you through every step, and clean up daily.
Every day water sits in your basement, mold spreads and your foundation weakens. Talk to a real Markham waterproofing expert today — free advice, no pressure.