What causes a popping or cracking noise from my eavestroughs on cold Ottawa mornings?

That popping or cracking sound you're hearing on cold Ottawa mornings is almost certainly thermal contraction — your eavestrough system physically shrinking as overnight temperatures drop, then expanding again as the morning sun warms the metal. It's one of the most common questions Ottawa homeowners have in winter, and the good news is that the noise itself is usually harmless. Understanding why it happens, though, can help you catch situations where it signals something more serious.

Why Ottawa's Climate Makes This Especially Pronounced

Ottawa's temperature swings are among the most extreme of any major Canadian city, and your eavestroughs feel every degree of it. Aluminum expands and contracts approximately 1 millimetre per metre for every 10 degrees Celsius of temperature change. On a typical Ottawa home with a 10-metre run of eavestrough, that means the gutter is physically shifting more than 6 millimetres between a cold January night at minus 25 and a sunny afternoon at plus 5. That movement has to go somewhere, and when it's restricted — by a tight end cap, a rigid downspout connection, or a hanger that's been fastened too snugly — the system releases that tension suddenly with a sharp pop or crack.

The noise is most dramatic in January and February when overnight lows regularly hit minus 25 to minus 30 degrees Celsius, and then the morning sun hits south- and west-facing eavestroughs and warms the metal rapidly. The faster the temperature change, the louder and more frequent the sounds. Homes in areas with open southern exposure, like newer subdivisions in Barrhaven, Kanata, or Orleans, often experience this more noticeably than homes shaded by Ottawa's mature urban tree canopy.

The sound can also come from ice movement inside the gutter. Ottawa experiences 50 or more freeze-thaw cycles per winter, meaning water that entered the eavestrough, partially froze, and then refreezes overnight creates internal pressure. When that ice shifts or cracks as temperatures change, it produces sounds that are easy to confuse with the eavestrough itself moving. This version of the noise is worth paying closer attention to, because it means water is sitting in your gutters — which points to either a drainage slope problem or a blocked downspout.

From a practical standpoint, there are a few things worth checking when you hear these sounds regularly. First, look at your downspout connections — a rigid elbow fastened tightly against a wall with no room to flex is a common restriction point. Experienced Ottawa contractors often leave a small amount of play at downspout joints specifically to allow for thermal movement. Second, check whether your hangers look like they're pulling away from the fascia board, which can happen when a system that can't move freely transfers stress to the mounting points instead. Third, if the cracking is accompanied by visible sagging or sections pulling away from the roofline, that's a sign the hangers may have been spaced too far apart — in Ottawa, 24 inches is the maximum recommended hanger spacing, and many contractors here go to 18 inches for added security against snow loading.

For most Ottawa homeowners, the popping and cracking is simply the sound of a normal eavestrough doing its job in a demanding climate. But if you're also noticing water stains on your fascia, ice buildup at the roofline, or sections that look visibly out of alignment, it's worth having a professional take a look before spring. You can browse eavestrough contractors serving Ottawa through the Ottawa Construction Network directory at justynrookcontracting.com — it's a free resource and a good starting point for getting a few quotes once the season opens up.