Proper Eavestrough Slope — How to Check Yours in Ottawa

The proper slope for eavestroughs is one-quarter inch of drop for every 10 feet of horizontal run toward the nearest downspout. This translates to roughly a half-inch drop over a 20-foot section — enough grade to keep water moving steadily without being so steep that the gutter visually sags at the low end. For runs longer than 40 feet, most Ottawa contractors install the high point in the centre with a slope running down toward downspouts at both ends, keeping the maximum vertical drop at any single point to about one inch.

How to Check Your Slope

The simplest way to test your slope is with a garden hose and a helper. Position the hose at the farthest point from the downspout and let water run at a moderate flow. Walk along the eavestrough at ground level and watch for water movement. It should flow steadily toward the downspout without pooling anywhere in the middle. If water collects in visible puddles or moves sluggishly, your slope is insufficient. You can also check with a 4-foot level held inside the gutter — the bubble should sit slightly off-centre toward the downspout end, not dead centre.

Ottawa's climate is particularly hard on eavestrough slope. The 50-plus freeze-thaw cycles each winter cause fascia boards to flex, hanger screws to loosen in expanding and contracting wood, and ice loading to physically push sections downward. A system that was perfectly sloped at installation can lose its grade within 5 to 10 years in Ottawa conditions. Heavy snow loads — wet snow weighing 200 to 500 kilograms per cubic metre — compound the problem by bending hangers and pulling the gutter away from the fascia at its mounting points.

The consequences of improper slope go beyond simple pooling. Standing water in eavestroughs accelerates corrosion of aluminum, breeds mosquitoes in warmer months, and creates ice dams in winter as pooled water freezes and expands. In Ottawa's extreme cold, ice forming in a flat section can crack seams and split gutter joints, turning a slope problem into a leak problem by spring.

Re-sloping eavestroughs is a common repair that involves adjusting hanger positions along the run. On older homes with spike-and-ferrule hangers, the spikes are pulled, new pilot holes are drilled at the correct height, and the spikes are re-driven. On homes with modern hidden clip hangers, the clips are unscrewed and repositioned. A professional re-slope in Ottawa typically costs $150 to $400 per run depending on length and accessibility. While handy homeowners can attempt this on single-storey homes with proper ladder safety, any work on two-storey homes or steep rooflines is best left to a professional with proper fall protection.

If your eavestroughs need re-sloping — especially if the hangers themselves are damaged or the fascia has softened from moisture exposure — connecting with an eavestrough contractor through the Ottawa Construction Network directory at justynrookcontracting.com ensures you get a proper assessment and competitive quotes from local professionals.