With all the rain we have been having lately, it made me think about an issue that most
people have around their homes right now. They don’t even recognize this as a problem that
needs to be corrected. It can actually cause damage over time if left unchecked. What could
this be, you ask? I’m talking about downspouts. Most downspouts stop abruptly, or terminate,
at the base of your home.
Homeowners need to keep water and moisture intrusion to a minimum around their house. It
is a very common issue to see downspouts terminate right beside the house. Most downspouts
just pour out beside the home without any kind of diversion. Downspouts are supposed to
terminate away from the house at least four to six feet, ten if possible, depending on soil
conditions. The reason being that water flows away from the house and its foundation. This
allows water to move away in a safe direction and not flow into the back filled soil around the
house, which can cause foundation problems or water intrusion into the basement.
Some homes only have splash blocks installed under downspouts. Splash blocks only work if
the grade around the house is proper. Proper grade is described as “ the soil should slope
away from the house at a rate of six inches for the first ten feet”. In West Virginia, some yards
are unable to obtain proper grade around the house because of the terrain. While this is better
than no diversion at all, it is not sufficient enough in some cases to disperse the amount of water
collected by gutters during a storm. Most people underestimate just how much water a roof
deals with during a rainstorm. For every 1000 square feet of roof surface, 620 gallons of
rainwater will flow through the gutters with one inch of rain. Storms can often dump one inch or
more of rain in our area. A few inches of rain falling on the roof of a house can produce several
thousand gallons of water runoff. This runoff must be channeled away from the home's
foundation. Otherwise, the excess water can quickly saturate the soil surrounding the building
and wick through the foundation to the interior. Once inside, this moisture can lead to a variety
of problems, including mold and wood rot. Excess moisture can also cause indoor air quality
problems. (see illustration)
This problem can often easily be corrected by adding extensions to the downspouts that will
allow rainwater to move away from the house and to a safe location. If the grade to the house is
a challenge, then underground drainage pipes may be a good solution to divert the rainwater
from the foundation.
Check out this informative video from This Old House that helps illustrate this point and give
some good options to help divert rainwater away from the house.
Please contact us to schedule your home inspection and allow us to take care of all your home