UPSTAIRS TOO HOT?

If the upper floors of your home become noticeably hotter than the rest of the house in summer — and your air conditioner runs constantly without keeping up — the cause is almost never the AC unit. It is the attic directly above you.

Here is what is happening: as outdoor temperatures climb through July and August, solar radiation heats your roof surface to temperatures that can exceed 70°C on a dark shingle. That heat radiates directly into the attic space below, which — without adequate ventilation — has nowhere to go. Attic air temperatures in a poorly ventilated Ontario home routinely exceed 60°C in peak summer. That superheated air radiates downward through your ceiling insulation and into your living space, making the upper floor feel like an oven regardless of how hard your cooling system works.