Just last night, I was watching the British Broadcasting Show
Ground
Force. The stars of the show had come to Atlanta, Georgia to renew the
backyard of a home. As dawn broke on the second day of the two-day shoot, the
stars of the show and the homeowner discovered that an overnight rainstorm had
flooded the side yard and part of the back yard where the new pond, garden and
deck were being installed. I know, you are wondering what in the world this has
to do with your new home in Chicago. In one word: Everything!
For two brief seconds, the videographer showed the cause of the flooding. The
downspouts from the roof terminated at the bottom of the exterior walls and the
rushing water simply hit a two-foot long concrete or plastic splash block. The
only purpose the diverter served was to absorb and spread out the energy of the
falling water. Without the splash block, the soil around the house would quickly
erode. The roof water was not being piped away from the home.
Many building codes do not mandate that rain water from a roof be piped away
from the foundation. Keep in mind that building codes are different in many
parts of the nation. We are getting very close to having one national building
code, but even when we do, local building officials can tweak the code to match
local practices and such.
Add to this the stormwater management problem many have just started to
realize in the past 15 years. Do some research and you will discover that urban
and suburban flooding has become a reality during the past 20 years. Part of
this is because storm water systems designed many years ago simply
underestimated the volume of water that is generated by hard surface house
roofs, driveways, patios, parking lots, etc. I don't think that engineers 50 or
75 years ago ever dreamed a shopping mall or a subdivision with hundreds of
homes might ever exist.
Modern planners and engineers deal with this storm water using sophisticated
water retention systems. Roof downspout water can be piped directly to
underground storm water retention basins. In some instances it can flow into
open retention or detention features. The bottom line is that your new home
should become a responsible member of the community. The water from your roof
should be captured and redirected to a place where it does not cause a problem
on your lot or the lot of a neighbor. At the very least, it should be released
slowly so it does not overwhelm the natural waterways near your home.
If you are lucky enough to build in a community that requires storm water to
be piped to a central location, be sure the piping on your lot is the right type
and it is installed the correct way. Even if you are not required to discharge
your storm water to a central location, it is still a great idea to divert it as
far away from your home as possible.
I prefer to use four inch diameter plastic sewer line pipe for down spout
drain lines. This piping is very durable and the joints between sections of pipe
and the fittings are very tight. You can often buy fittings that have rubber
seals or ones that are glued with a regular solvent glue. Using either type
insures that water will not leak from the pipe and that tree roots will not
enter the piping system.
The installer of the piping should avoid the use of 90-degree fittings except
where the pipe terminates against the foundation wall and turns up to capture
the roof downspout pipe. These tight bends when placed downstream in the piping
are enormous obstacles for plumbers or drain cleaning companies. If your piping
gets clogged in the future, 90-degree bends may prevent a company from extending
a metal drain cleaning wire down the piping system. You can easily create a 90-degree turn by gluing two 45-degree fittings together. Two 45-degree bends
create a gentle turn that the drain cleaning equipment can navigate.
The piping should not be buried in the un-compacted fill dirt alongside a
foundation. This dirt settles over time and the piping can fracture or develop a
negative pitch where water actually flows the wrong direction. It is better to
put the pipe in the undisturbed soil that usually can be found about 4 or 5 feet
away from the foundation. The buried pipe can cross this uncompacted soil to get
to the virgin soil, but make sure it has plenty of pitch. I recommend one inch
of fall for every two feet of run as it crosses this danger zone. Once the pipe
is in good soil, it can have a pitch of 1/8 to 1/4 inch of fall per linear foot
of run.
If at all possible, take photos of the installation of this system. These
photos will prove invaluable years from now as they will help you locate the
piping should you need to dig a hole or excavate for any reason on your
property. Place the photos and negatives in a safe place such as your electrical
circuit board panel. Put the photos in a sturdy labeled envelope and nail it to
an open spot next to the electric panel. The circuit breaker panel board is
rarely disturbed and makes a great spot to store facts about your home.