|
Home
Services
Photos
Contact Information
Tips for Property
Owners
Resume
Links
Search
| |
WET BASEMENTS OR CRAWL SPACES
Standing water inside or seepage into residential crawl spaces
and basements can cause frustrating problems for homeowners as well as lead to
immediate and long term problems. Some of these include:
Wet basements and crawl spaces are sources of high humidity, which can produce
surface condensation, mildew and fungi, musty odors, and an unhealthful
environment. Such moisture can cause deterioration of floor joists, beams,
subflooring, insulation, and electrical-mechanical systems. Prolonged water
around the footing and foundation wall can soften the soil and weaken its
bearing capacity, increasing the possibility of foundation settlement and
cracking. Serious seepage under the foundation footer may erode soil away and
cause the wall to drop or crack.
Deterioration of the basement wall itself.
Wet insulation has little insulating value resulting in increased heating and
cooling costs.
Difficult to inspect and service electrical, plumbing and heating systems in wet
crawl spaces.
Reduction in the value of the residence.
Most wet basements or crawl spaces are caused by surface water which is not
adequately drained away from the foundation wall. Sources of this water include
the following:
Water from the roof where no gutters are present or roof water resulting from
gutter leaks or overflows resulting from gutter clogs. Frequently, a downspout
ends at the corner of the house without a splash block or elbow and extension,
leaving roof water to concentrate at that point and seep into the soil next to
the foundation wall. A typical 2000 square foot roof can produce almost 1250
gallons of water during just 1 inch of rainfall. Downspouts should be extended
away from the house and grading modified to promote drainage away from the
foundation walls.
Rainwater runoff from the adjacent lawn, walks, or patios. If surface runoff is
directed toward the foundation wall through either grading of the site or sloped
concrete or asphalt surfaces, this water will pond and eventually soak into the
soil, thus becoming a potential source of basement or crawl space water.
Subsurface or groundwater may be intercepted or dammed up by a basement or
foundation wall. Houses which are built downslope on or at the base of hillsides
are particularly vulnerable since there is greater opportunity for surface water
to soak into the soil to become groundwater and because groundwater flows
downhill by gravity. Foundation walls act like dams and can intercept and trap
this subsurface water, causing pressure build-up on the outside and forcing
water through joints and cracks in basement walls or seepage under the footer.
Improperly installed, clogged, collapsed, or leaky drains may not allow
downspout water or foundation wall water to escape. Perimeter, footer, or
foundation drains are installed around the exterior of a house below the
basement floor to intercept and dispose of subsurface water to eliminate
groundwater build-up and seepage under the house. If these drains are improperly
installed or become clogged with silt or roots, they will not operate as
intended. Sometimes an otherwise good perimeter drain gets covered up at its
end(s) during the final backfilling or landscaping stages of construction and
the intercepted water has no place to go but to build up behind the foundation
wall and eventually to seep into the basement or crawl space.
Soil continuously draws water up from subsurface groundwater sources in a crawl
space like a blotter by a mechanism known as capillary attraction. The finer the
soil (e.g. clays), the more aggressive the capillary pumping action. As the
water rises to the surface, it evaporates into the crawl space or basement. Such
ground moisture can be a significant source of dampness and humidity under a
house, even without standing water. The presence of capillary water is often
indicated by a whitish residue, left on the ground surface of the crawl spaces,
resulting from evaporation of water containing minerals and salts. Lack of a
moisture barrier, such as plastic sheet, will allow this capillary action and
evaporation to contribute almost unlimited moisture sources to crawl space
areas.
Tips for Buying a New Home
Work with an Engineer or Architect, to help you locate the new house on the lot
and at an elevation which would minimize potential surface or groundwater
drainage problems and save drainage costs.
If a flowing stream or dry ditch borders your lot, check with local planning
agency authorities or a hydrologic engineer for potential flooding, whether in a
designated 100-year flood hazard zone or in an area where lesser but more
frequent flooding could occur or has occurred.
Work with a reputable home builder who can give you reference names or locations
for houses that he has built. If the house you are looking at is already built,
find out who constructed it and ask your realtor for references to homes built
by the same builder. Visit these sites and check for patterns of any drainage
problems.
Check to make sure that the perimeter foundation drain, basement drain(s), or
crawl space drain has an unobstructed outlet to a ditch or storm sewer which
leads away from the house.
If you are considering the purchase of a newly built house, pay special
attention around the outside and the basement or crawl space for backsloping
lawns and landscaping toward foundation walls, backsloping driveways (toward
garage), stoops, walks or patios which force surface water toward the foundation
wall.
Tips for Buying an Older Home
Visit the house during or shortly after a prolonged or heavy storm. Check for
water in the basement or crawl space. Ask the realtor about any known water
problems--inside or outside--by the previous owner.
Check with the neighbors to see if the house that you are looking at has had a
history of drainage problems or wet/damp basement or crawl space.
For houses with basements, carefully check for stain signs of standing water
around the walls or seepage coming through the walls, especially along the
wall(s) having the highest outside ground level. Look for whitish salt deposits
on inside foundation walls left from moisture seepage and evaporation. For
houses with crawl spaces use a flashlight and check for current or previous
water ponding, mud, mildew, condensation on various surfaces, or sagging or wet
insulation.
Check the basement and crawl space for musty odors and signs of mildew,
condensation on surfaces, and unusually heavy rust deposits. Check the inside
corners for cracks and separation of blocks at the joints from foundation
settlement.
The suggestion that water seepage into basement or crawl spaces is normal and
should not be a concern is a myth. Either ask that the source of the problem be
eliminated or look for another house.
Back
|
Jansen | Kiener
Your Solution