Ontario Building Code Basics Every Buyer Should Know

I was crawling through an attic on Plains Road last Tuesday when I heard it - that distinct dripping sound that makes every home inspector's heart sink. The homeowner had called about "some minor water stains" on their bedroom ceiling, but when I shone my flashlight toward the eaves, I could see ice formations along the roof edge that told a much bigger story. Water was pooling behind a dam of ice, and with the spring thaw coming in April 2026, this 1970s split-level was about to become a very expensive lesson in physics.

Ice dams. They're happening right now across Burlington, and I've been seeing them in three out of every four inspections this winter.

What I find most concerning isn't just the immediate water damage - it's how many buyers completely underestimate what they're looking at. You walk into a beautiful home in Aldershot, everything looks perfect from the street, and then you spot those telltale brown stains on the ceiling or that slight bulge in the drywall. The seller says it's "just a small leak we're dealing with," but I'm already calculating repair costs that'll hit $12,340 for proper remediation.

Here's what's actually happening up there. Snow accumulates on your roof - normal enough. But when heat from your house warms the roof surface, that snow starts melting. The water runs down toward the gutters, but here's where it gets interesting: the eaves are still cold because they're not getting heat from the house interior. So the water refreezes right at the edge, creating a dam.

More water backs up behind this ice wall. It sits there, finding every tiny gap in your shingles, every microscopic crack in the flashing. Water always wins these battles.

I was in a gorgeous Tyandaga home just last week - asking price $940,000, looked immaculate. The buyers were already talking about moving in by March. Then I climbed up to check the attic space and found ice formations so thick they looked like stalactites. The insulation was soaked. The wooden roof decking had water stains that ran three feet back from the eaves. This wasn't a recent problem.

Burlington's housing stock from the 1960s and 1970s is particularly vulnerable to ice dam issues, and buyers always underestimate this risk. These homes were built during an era when insulation standards were different, when energy efficiency wasn't the priority it is today. The result? Heat loss through the roof that creates perfect ice dam conditions every winter.

You'll see the worst damage in split-levels and bungalows where the roof line meets exterior walls. The physics just work against you in these designs.

But here's what surprised me this season - I'm finding ice dam damage in newer builds too. A 1980s two-story on Fairview had $18,750 worth of interior damage because the previous owners never addressed inadequate attic ventilation. The insurance company had already been through twice. Sound familiar?

The repair costs add up faster than most people expect. Damaged drywall runs about $8,400 for an average bedroom. If the insulation needs replacing - and it usually does after water intrusion - add another $4,200. Roof repairs to address the underlying ventilation issues? That's easily $15,600 for proper soffit and ridge venting in a typical Burlington home.

I've seen buyers walk away from deals over ice dam damage, and honestly, sometimes that's the smart move. In 15 years I've never seen a half-hearted ice dam repair job go well. You either fix the root cause - the heat loss and ventilation issues - or you're just setting yourself up for the same problem next winter.

The thing about ice dams is they're not really about your roof. They're about your attic. Poor insulation lets heat escape through the roof decking. Inadequate ventilation means that heat has nowhere to go except up through the shingles. You can scrape ice off your gutters all you want, but until you address what's happening in that attic space, you're just treating symptoms.

Guess what we found in that Plains Road house I mentioned? The attic had blown-in insulation from 1973 that had settled to about half its original thickness. The soffit vents were blocked with old insulation. There was no ridge venting at all. The homeowner had been dealing with ice dams for eight winters and never understood why.

Downtown Burlington's older homes often have even more complex ice dam issues because of their roof designs. Multiple levels, dormers, valleys where snow accumulates - these architectural features that make the homes charming also create perfect conditions for ice problems.

Spring weather in Ontario is particularly brutal on homes with ice dam damage. Those freeze-thaw cycles we get through March and April? Each one forces more water into places it shouldn't be. What looks like minor ceiling stains in February can become major structural issues by May.

The buyers for that Plains Road property ended up negotiating a $22,000 credit to address the ice dam issues properly. Smart move. They're planning to air-seal the attic floor, add proper insulation, and install ridge venting before next winter.

If you're buying a Burlington home this season, don't let anyone tell you ice dam damage is "normal wear and tear." Get a proper inspection that includes attic evaluation, and budget for real repairs. Your future self will thank you when April 2026 rolls around and your ceilings stay dry.