Gutters and Downspouts – Making them Work Well Together

A gutter system is designed to collect rainwater from the roof and channel it to the downspouts, where they direct water away from the foundation. But it’s not just about functionality: to improve your home’s exterior, gutter and downspout profiles should complement each other. Whether you’re having a new gutter system installed or plan to improve the functionality of your current gutters, understanding how they work together will help you choose what’s best for your home.

Corresponding Sizes

For 5-inch gutters, the typical corresponding downspout size is 2×3 inch rectangle or 3” round. Larger residences that use 6” inch gutters have 3×4” downpipes (rectangular) or round 4-inch downspouts.

Because of architectural design, roof configuration, climate, microclimate, or a combination of these factors, every house is unique. Standard gutter system guidelines can be adapted to accommodate specific situations. For example, a homeowner might install standard 5” gutters on an average sized home but need one 3×4” downpipe since there is no room for two downspouts.

Location, Location, Location

For gutters and downpipes to work optimally in conjunction with one another, the location of the downspout is especially important. Aesthetically speaking, downspouts should be placed discretely, out of eye-line, such as at the corners, on the side of the structure or at the back.

Functional considerations of downspout placement include enough space for the downpipe to deposit water safely away from the foundation; not too close to a neighbour’s property line; and sufficiently sloped downward from the house to avoid washing away soil.

Number of Downpipes

The general guideline is one downspout for every 35 feet to 40 feet of gutter. It also depends on the size of the roof – the larger the surface area, the more water enters the gutter system. A roof configuration that includes multiple levels might need a gutter system with more than the recommended number of downpipes per linear feet of guttering.

Connecting Gutters to Downspouts

In order for water to flow properly from the gutter channel and into the downspout, two key parts, the gutter outlet and a downspout elbow, are required.

The gutter outlet connects the downspout to the system. Whatever its shape, the outlet should correspond in size to the downspout being installed. A 3-inch round gutter outlet can be used on a 2×3” (rectangle) downpipe.

The downspout elbow, (where it joins to the outlet), dictates the direction of the downpipe, either directly onto the wall or away from it. The type of elbow selected for the downspout should be compatible with the gutter outlet.