Avoid Basement Flooding By Using Natural Drainage
By Jim Sulski
Summary: Many basements flood when the rainy
season begins. Jim explains how to keep the rain water away from your house
and out of your basement.
During the warm weather months, many homeowners will look down into their
basements to find rising waters.
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A basement can flood - or at least suffer from seepage - during a rainstorm
as the ground around a home becomes saturated with rainwater.
Water, as it flows underground, follows the path of least resistance, which
can often be along the exterior of a basement wall. The pressure of rain water
forces it through any small cracks in the basement walls and floors, or at the
joint where the basement walls meet the floor.
One way to prevent basement flooding and seepage is to waterproof the exterior
basement walls of your home. That requires an excavation and a coating of the
walls, a fairly expensive process.
Another is to install a sump pump system, again another fairly expensive task
for the typical homeowner.
A less expensive although fairly laborious method to waterproof your basement
is through natural drainage techniques.
In a nutshell, this involves routing rain water away from your house, preventing
it from seeping in through basement walls.
SLOPES AND SWALES
For example, many basement seepage problems are the result of poor grading
of the ground away from the house. The ground around a home should slope away
from the house. Sidewalks, patios, driveways that lean towards the house can
also aggravate the problem.
To remedy the situation, the grade of the ground should be changed. This may
require a pickup bed or two of dirt that can be spread over the ground.
The grade should ideally slope about an inch or slightly more for every ten
feet of ground. Sloping the ground will also require you to do a little landscaping.
It's best to remove existing turf and then dump in the backfill. Then place
the turf back over the new ground.
Sloping sidewalks, patios and driveways, meanwhile, may have to be rebuilt
or repitched to change the flow of water.
If you live on a fairly large lot, another way to divert water is to build
a swale - a shallow trench that encircles three sides of the house in a sort
of horseshoe pattern.
Dig the swale at least six feet from the house. Make sure that the ground between
the house and the swale pitches toward the swale. Then fill the swale with gravel
or crushed stones and cover it with dirt and turf.
Another way to divert water from your home's property is to construct drain
tile pipes into the ground. These perforated ridged black plastic tubes gather
water during rainstorms and thanks to a downward pitch, carry the water away
from the house.
The first step in constructing a drainpipe is to map out an underground channel
where it will go. Ideally, as with a swale, the ground from the house will pitch
towards the channel containing the drain tile pipe.
Take note of any sidewalks or driveways the pipe may have to cross under. In
addition, where it discharges - preferably near a city storm sewer or a retention
pond - is also highly important.
Once you've mapped out a plan, dig out a trench about a foot deep to support
the drain tile pipe. Next, lay in about an inch or two of gravel. Then place
the pipe in the trench, with the perforations face down.
Cover the pipe with more gravel. Otherwise, the dirt can clog the holes. Finally,
top the gravel off with a few inches of dirt and sod.
GUTTER SYSTEM IMPROVEMENTS
Another key to preventing basement seepage is making sure your home's gutter
system is in good shape and functioning properly.
If the gutters are clogged, rainwater will pour over the sides, saturating
the ground next to the foundation of the house. Clean gutters ensure the water
is carried away from the house.
In addition, placement of the downspouts, the vertical pipes that carry the
water from the gutters to the ground below, is critical. If the downspouts are
just exhausting the water right next the foundation, that's just aggravating
Downspouts should exhaust as far as away from the house as possible. This can
be accomplished by extensions, such as a piece of downspout that runs along
the ground on a downward slop, or downspout extensions that unroll when filled
with water. The latter is especially good for downspouts that descend to a sidewalk.
A downspout can also be attached to an underground drain tile pipe to divert
water away from the house.
© by Jim Sulski. All rights reserved. February 15, 2005.
NOTE: This column is distributed by Real Estate Matters Syndicate,
PO Box 366, Glencoe, Illinois, 60022. This column may not be resold, reprinted,
resyndicated or redistributed without written permission from the publisher.
© 2005 by Ilyce R. Glink. Distributed by Real Estate Matters Syndicate.