Neglecting gutters, downspouts can damage building foundation
Wednesday, November 7, 2001
It will never cease to amaze us how difficult it has been to get the word out about how important it is to keep water away from a home's foundation. Take gutters and downspouts for example.
There's no better way than using these to collect roof water and prevent it from dropping onto the ground next to the foundation. Believe it or not, in some places local codes don't require gutters or downspouts. Fortunately, for some, surface-water management is taken very seriously.
In many communities, strict rules are in place wherein gutters and downspouts not only are required, but also must be connected to an underground drainage system that transports collected water to a public-storm drain system.
It gets even more complicated. These lawmakers require that watershed from these systems not cross over sidewalks. That's right, the pipe has to go under the sidewalk. It can't be exposed to daylight on your side of the sidewalk and run out to the street over a public walkway. We think these are good rules.
Regardless, these rules are not enforced against existing homes. If you don't have a gutter and downspout system, chances are you will never have to install one. You'll do so only if you decide to on your own. As far as your rights are concerned, the latter is probably sweet music to your ears. On the other hand, as a homeowner it might cost tens of thousands of dollars to fix your home someday. Water can take its toll.
Need a drainage system
If you have downspouts, at least you are properly collecting damaging roof water and funneling it into a management system that will possibly save you big-time heartache down the road. However, if you do have gutters and downspouts, and the water isn't being collected into a drainage system, you might be in for it anyway. Collecting all of that water and letting it out near the foundation can be even worse than not having gutters and downspouts at all. Collecting all that water and letting it fall next to the foundation in massive quantities can destroy your home over time.
You don't have to spend thousands of dollars developing a fancy underground aqueduct. But you do need to pay special attention to what is happening to the water that your roof collects.
If you have an average-size American home, your roof collects water from an area over 2,000 square feet in size. That's a lot of collection area. Suddenly, all of that water ends up coming down through six or eight downspouts -- altogether less than 2 square feet. Talk about a buildup of water.
One thing you can do if you don't have an underground water-delivery system is to extend the downspouts so that they don't discharge water near your home. The experts tell us 3 feet is sufficient. We think that is a minimum distance. Twenty feet is probably better.
A lot depends on the soil around your house. You might want to call a soils engineer in your area. Most will be able to answer over the phone. Besides an extension, you will also want something that will prevent the rushing water from eroding your landscape. Rivers move mountains and downspout discharge can literally move your landscape.
The experts usually recommend that gravel or rocks be placed at the end of a discharge pipe to reduce the chance of erosion. With homes, a common practice is to use something called a splash block. Discharge water beats on the block, not the ground. Splash blocks are OK most of the time, but might be lacking during torrential downpours.
What's the answer? We both have underground drainage systems on our properties because we want our property to be there when we get old. But, if the thought of an underground system makes you pocketbook-nervous, you should at least install extensions on all downspouts that end within a foot or two of your foundation.
How far should they be extended? As far as you can afford. And it doesn't take anything fancy.