Sloping the Streams Around Your Roof

All water responds similarly to gravity and slopes. When we think about it, we realise our eavestroughs are like canals around our roofs. The valleys and drip edges are catchment areas, while we can imagine the downspouts as cataracts plunging down.

Now water has the power to create mighty ravines, and canyons in nature to achieve the right slopes to harness gravity. Since our eavestroughs are designed to resist this abrasive force, it follows we do need to slope them correctly.

So What Is a Proper Eavestrough Slope Then?

In our many years’ experience, the average Calgary homeowner does not give their eavestrough slopes a second thought. As long as it finds its way down, all is good they imagine. However, correct gutter pitch, as some call it, is actually critical to the performance of the entire system.

That’s because while an eavestrough may appear level at a distance, especially when viewed from below, it should actually slope gently to prevent water pooling in the length. But too much of a slope reduces trough capacity. That’s why our industry has norms professionals follow.

The general rule of thumb is a quarter-inch of fall for every ten-feet of length towards the downspout. Therefore, by way of an example, a forty-foot length of downspout should have a fall of one inch.

Problems with Incorrectly-Sloped Eavestroughs


An excessively sloping eavestrough will cause water to flow too fast. Overflows can splash fascias and soffits leading to rot. But they can also splash down siding, and trickle into gaps in foundations which could compromise building structure.


An under-sloping eavestrough will cause water to accumulate, adding weight-stress to supporting brackets and fascias. This can and will cause gradual damage, the first sign of this may be sagging as the run begins to pull away.


Debris in the form of leaves and other wind-blown matter cannot flush correctly through downspouts without adequate water flow. This will gradually turn into sludge, add more weight, and become a fertile ground for plants to take root.

Installing New Eavestroughs is a Specialist Task.

Valiant Exteriors has all the knowledge you need to make a decent job of eavestrough installation. We right-size our systems to match roof expanse, and we scrupulously follow industry standards. Our prices are competitive because we are family-owned and managed. Please give a call to learn more.

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Roof Eavestrough and Downspout in Place (Stilfehler BY CC 4.0)