Ice built up under my New Brunswick metal roof, is that normal?

Ice buildup under a metal roof in New Brunswick is actually a common problem, but it's not something you should ignore — it's a sign that heat is escaping from your living space into the attic. What you're describing is almost certainly ice damming, and NB's freeze-thaw cycle makes it worse here than almost anywhere else in the country.

Here's what's happening: warm air leaks from your heated living space into the attic, warms the roof deck, and melts the snow above it. That meltwater runs down toward the cold eaves, refreezes, and backs up under the metal panels. Metal roofs actually make this more visible because the panels can lift slightly as ice expands underneath — on asphalt shingles, the same process happens but you often don't notice until water is dripping through your ceiling.

The root cause is almost always an insulation and air sealing problem, not a roofing problem. Before spending money on the roof itself, you need to look at what's happening in your attic. Common culprits in New Brunswick homes include:

• Bypasses around pot lights, plumbing stacks, and interior partition walls that let warm air pour into the attic
• Insufficient attic insulation (pre-2000 NB homes often have R-20 or less — current NBC 2020 Tier 2 standards call for significantly more)
• Blocked or inadequate soffit-to-ridge ventilation

The fix is usually a two-part approach. First, air seal every penetration between the living space and attic — this is the most critical step and often the cheapest. Second, top up your attic insulation. NB Power's Total Home Energy Savings Program offers rebates for insulation upgrades, so it's worth calling them before you start work to understand what's available.

If your home is in the Fredericton, Moncton, or Saint John area and was built before the 1990s, there's a real chance the attic insulation is well below current standards. Rural homes and older farmhouses throughout the Saint John River valley and northern NB are especially prone to this — steep-pitched roofs with minimal insulation were common for decades.

On the roofing side, make sure your metal roof was installed with a proper ice and water shield membrane at the eaves (minimum 900mm past the interior wall line per NBC, though many installers go further in NB's climate). If the original installation skipped this or used only felt paper, ice damming will be a recurring battle regardless of how well you insulate.

A professional energy audit is the smartest first step — a certified energy advisor can use a blower door test and thermal imaging to pinpoint exactly where warm air is escaping. This typically costs $300–$600 in New Brunswick and gives you a clear action plan rather than guessing. NB Power can often connect you with an advisor through their efficiency programs.

This is a project where the diagnostic work is DIY-friendly (you can inspect the attic yourself with a flashlight and a tape measure), but the air sealing and insulation work benefits from a professional, especially if your attic has complex geometry or limited access. Browse insulation and roofing contractors in the New Brunswick Construction Network directory to find local professionals familiar with NB's climate demands.