Moving water away from your home. From your roof to your lawn.

Gutters and Downspouts. Are they a good idea?

There are two functions of gutters and downspouts.  One, they protect the walls of your home from water that would run off your roof.  Water running off the roof will damage the wall surfaces and cause local erosion at the ground level.  Two, and most importantly, they contribute to keeping your basement dry.  Let’s look at the two components, Gutters and Downspouts.


Gutters, for most houses, are attached to the fascia (front edge of the roof system) at the eaves.  This is why they are commonly called Eave Troughs.  There are two sizes of gutters used generally, 4 inch and 5 inch widths.  5 inch gutters are better at catching the water as it comes off the roof and are less likely to over-fill.  The gutters should slope gently to the downspouts so that water does not sit in the trough risking leakage into the wall system.


Downspouts are generally the same material as the gutters.  These run vertically down and lead the water away from the building.  The ideal amount of downspouts for a home is one for every 40 feet of gutters.  Moving the water from the building is very important and the downspout should discharge a minimum of 6 feet away from the foundation.  Sometimes the downspout discharge is underground.  This is a challenge for home owners as it is not always possible to know if the underground pipe (the pipe can be clay tile, cast iron or plastic) has been blocked or broken.

What to watch for.

Gutters:  The most common problem with these is that they leak.  They can rust if they are galvanised steel or leak at the joints if they are aluminium.  Gutters can get loose if they are not secured to a solid fascia or if there are not enough gutter nails supporting the length.  This should be done every 2 to 3 feet.  Debris is always a challenge for gutters.  This is especially true if there are trees near the home.  It is generally worthwhile to clean out the gutters once a year.

Downspouts:  There are 2 common mistakes with the installation of downspouts.  First is that there are not enough of them for the length of gutters (1 per every 40 feet of gutter).  The lack of downspouts will result in gutters getting overwhelmed with water and spilling out.  The second mistake is that they do not discharge far enough away from the building or are damaged so that the water spills too close to the foundation.  There are a few products that allow you to extend the distance of the downspout but the best is to simply add the same material on to reach the desired length.  Downspouts are also often loose against the wall.  This happens as a result of being hit or by ice forming against the building and pushing the downspout away from the wall.  It is well worth the time to check occasionally the condition of the downspouts and repair when needed.

When the downspout discharges form an upper roof to a lower roof, the section of the lower roof in the path of the water will deteriorate quickly as the water works away at the roofing material.  Ideally you would have a downspout extend to discharge into the gutter of the lower roof.



Posted by Jeremy Scratch

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