DEAR TIM: I am building a new home soon and I do not want
water drainage problems of any sort in my yard. My existing home is built on a
slab and I frequently have standing water around the house after a rainfall. My
new home will have a basement. Can I build a house with a dry basement or will
it leak over time and become damp, musty and useless? Surely there must be a way
to elimnate all water problems around a home. Amy C., Dubuque, IA
DEAR AMY: You bet it is possible to eliminate water problems
around the average home. The good news is that many of the things required to
achieve a dry, well drained lot are very economical. The largest expense will be
the cost to actually waterproof your new foundation. It is a one time expense
and if you use one of the better systems out there your basement, like mine,
will be bone dry for many years to come.
The first thing your builder needs to do is to make sure
that the top of your foundation or slab actually sticks high enough out of the
ground. All too often builders set houses into the ground too deeply. When this
happens it is nearly impossible for a builder to create gentle sloping grades
that direct water away from the house and to the lowest point of the lot where
water would have drained naturally before the house was built.
The model building codes are very specific about foundation drainage and many
state that the ground should slope at least six inches down in the first ten
feet of distance away from the house. If your house is built close to the lot
line a ditch needs to be built that allows similar natural drainage.
Water that leaves your roof can cause all sorts of problems if it is not
collected and piped away from the house. An average one floor house might have
approximately 2,400 square feet of surface area on the roof. When a storm
produces one inch of rain, the amount of water draining from the roof to the
ground equals nearly 1,500 gallons! Allowing this water to simply collect near
the house or discharge from down spouts onto simple splash blocks at the base of
a foundation is asking for trouble.
The better solution is to pipe this water away from the house. Many
municipalities are now requiring that this storm water be collected and put into
retention ponds before being allowed to enter natural drainage systems like
brooks and streams. Interior sump pump discharge pipes should also be connected
to these down spout drain pipes. Allowing sump water to discharge along side a
foundation is insanity. The water you just paid to pump will usually enter the
sump again in a matter of hours.
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Make sure your builder waterproofs your foundation. Do not
confuse true waterproofing systems with the thin sprayed-on asphalt that many
builders install. The thin asphalt coatings are damproofing and meet the minimum
code requirements for unfinished basement areas. My basement is actually
waterproofed. I used a thick modified asphalt compound that actually contains
rubber. The rubber allows the material to bridge small cracks that may develop
at a later date. The thick coating was then covered by a rigid fiberglass
insulation that keeps my basement walls warm and helps to channel water directly
to the drain tile at the base of my foundation.
There are other high quality waterproofing systems out there. Some are
actually synthetic rubbers that have incredible elastic properties. Other
systems use a natural clay that swells when it gets wet. You can even get
special urethanes that will waterproof a foundation. Finally, there are some
innovative plastic foundation wraps that claim to waterproof a foundation. These
plastic products come in large rolls and look like a muffin pan. The bumps in
the plastic create a pathway for water to easily flow down the sides of the
foundation to the drain tile.
The key to a dry basement and lot is to cooperate with Mother Nature. One of
her rules happens to be gravity. Use it to your advantage. Make sure that you
use gravity to pipe surface and sub-surface water away from your house as
quickly as possible. Do this and you will be the driest person on your
block.
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Comments
Henrietta
17 Dec 2007, 17:04
I have a home in Indiana. The lower level has a bedroom, shower, family
room and a sun porch. The utility room,bath room and bedroom get standing
water during a storm. I have had two contractors out who say I should dig
inside the home around the perimeter and install a drainage system to sump
pump. I feel like the outside should be tackled and sealed and drained to
the lake. Won't the water continue to come into the house and then drain?
AsktheBuilder
17 Dec 2007, 17:33
Henrietta,
Please read ALL of the columns in the Drainage category of my website. The
answer is there and your instincts are right! Wait until you discover how I
would solve that problem if I came to your house! :->
Michael in Long Island
03 Feb 2008, 14:05
Hi Tim,
I've read through your Patio, Drainage and Concrete sections but don't
really have the complete answer I need...
We bought a house and cleared a lot of brush. We also discovered that in
spite of the prior owner's claims, there are leaks into our basement. The
house is a typical Long Island Split Level with a full basement.
We are on the bottom of a hill yet our drainage problems are not on the
high side but on the patio (which is perpendicular to the high and low
side).
The patio, for some unknown reason, slopes towards the back of the house
and into the basement and den (den is on same level as the patio). Further
the patio is bi-level and the lower level is on the high side of the house!
Water, naturally is dammed by the level and it pools where the two levels
meet and where the den slab meets the basement drop. As such, I had to sand
bag this are heavily to prevent leakage into the den or basement.
We had some work done and windows replaced and new siding and some fix to
the concrete near a door where water came in. So far no problems in the
last major rainstorm which was a doozy.
My concern is what I can do where the two patios meet for the short term
and what we'll have to do for the long term.
A gutter and downspout was added to a short roof that helped accumulate
water on that area of the patio and now I need to move the water away and
off the patio.
It doesn't seem like an easy task other than replacing the patio but money
is very tight at the moment...
HELP!!!
I can send pictures if needed...
Thank you in advance,
Michael
AsktheBuilder
03 Feb 2008, 14:22
Michael,
How about reading my Concrete Overlay columns and think about adding a
wedge of overlay to create the positive drainage you need?
Michael in Long Island
03 Feb 2008, 15:37
Thank you!! I did not see that (of course)!
Thanks again,
Michael
Sandy
06 Feb 2008, 00:58
There's an area between my house that's built on a slab and the asphalt
driveway (about a foot wide) where water gathers, and it seems to be
getting into the house. What is the suggested solution to this problem. I
was thinking about having a trench dug and have a pvc drain pipe installed,
however this doesn't take the water away from the house. Have a better
idea? Thanks for your input!
AsktheBuilder
06 Feb 2008, 06:02
Sandy,
Unless I am missing something, the message in this column is pretty clear.
Read it again and tell me if it isn't possible to achieve positive slope in
this area.
Jack Cox
22 Feb 2008, 08:15
I have a drainage problem in my yard and was told I could use a sock pipe.
The pipe has slots and a sock over it. I had considered a french drain but
if the sock dosn't deterioate then that would be the cheapest route. My
neighbor has used sock pipe without any problems for over 10 years. I was
told the only way sock pipe gives problems if it is exposed to sun light.
Is this true? I don't want to lay the pipe with sock if it is going to rot
in the next 4 or 5 years.
Please advise.
AsktheBuilder
29 Feb 2008, 17:53
Jack,
Read all of my Drainage columns and do what I say in the columns.
Shawn Moore
04 Mar 2008, 10:56
Thanks for introducing me to French Drains. I am hopeful that they can help
what seems like a very big basement water problem.
We have an over active sump pump and our finsished basement leaks during
rainstorms. After reading your articles I feel the drainage around the lot
could be a factor, but am unsure if it will help in our low lying area. I
am also concerned that the groundwater or a spring is a major issue.
The sump pit is a ticking time bomb. When I bought this house a year ago
the basement floor had a hole chipped out with an active sump pump in the
pit. (It was the dry season so I had no idea about the problems I was
getting into) I had a plumber install a newer sump pump and a proper pit
with a battery backup system, so the pit is consequently larger now. The
scary part is that when it rains the water level in the pit comes within
inches of overflowing into the basement and the primary pump barely keeps
it at this level. It seems that larger sump pit installed allows much more
water to flow. Consequently the sump pump doesn't shut off during storms.
This will last for 12 hours or so depending on the amount of precipitation.
Then for a few days it will cycle on and off until the water level sits
about 4 inches below the foundation and no longer activates it.
A year ago, when it was just a small hole with the old sump pump, I don't
remember the sump ever staying on...it seemed to cycle, indicating to me
that there was less water coming in at that time.
I don't think this sump pit has any of the drainage tile routed to it.
Therefore I am not sure why it was orginally installed and if it is serving
a purpose now. I assume it was supposed to relieve pressure on the
foundation, however I have a hard time believing it is making any
difference fighting the amount of water that now flows into the pit.
The basement leaks in several areas during heavy rains and is getting worse
My questions are: Do I need this hole in my basement with the sump if there
are no weeping tiles drained to it? Do you have any suggestions regarding
the sump pit?
Are French Drains still a viable solution to reduce the amount of water in
the sump pit during rainstorms as it seems that this is a significant
amount of ground water coming from below?
If so should I also consider digging up my foundation and waterproofing
prior to installing the French Drains?
Thanks for any input...we don't have a lot of qualified people on this
subject in Nova Scotia...as most houses here do not require sumps.
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