This HouseMaster Information Guide will deal with the causes of water penetration and our recommendations to correct them.
Most wet damp basement, garage, crawl space and lower level conditions could be alleviated with minimum effort and expense. This is due to the fact that most water penetration occurs because its major causes (rain water from the roof and surface water) are not attended to and water accumulates around the perimeter of the house and eventually seeps in. The illustration shows some of the basic waterproofing techniques available to the home owner. However, since each house and its individual characteristics vary, a special program or plan of attack should be developed for each.
Water intrusion into subgrade areas affects many homes. Often it is simply the result of rainwater run-off from the roof and/or yard surfaces that accumulates around the perimeter of the house and eventually seeps through the foundation walls or cracks. But many damp or wet basement and crawlspace conditions can be reduced with minimal effort and expense.
Common Causes of Water Penetration
The causes of water penetration can be minor, readily apparent and fairly easily corrected or, in some cases, hard to detect and correct. Common causes of water penetration include:
- No gutters or downspouts to handle the roof water run-off.
- Overflowing gutters or downspouts that discharge rainwater at the foundation.
- A property that is relatively flat or slopes toward the house allowing surface water to collect against the foundation walls.
- Run-off from the street flows unobstructed down the driveway of a house located below street level.
- A subgrade basement entryway or window well that lacks a drain or cover, or has a clogged drain.
- Surface drains, catch basins, or underground lines that are clogged, saturating the soil or sending water toward the house.
- High indoor humidity that leads to condensation (or sweating) on cool surfaces (walls, floors, water pipes).
- Groundwater level (water table) that is close to or above the level of the crawlspace or basement floor.
- Naturally occurring underground water flow.
In developing a plan of action to address water penetration conditions, it is important to address the cause of the condition and not the effect. You want to try and stop water before it seeps in and causes damage rather than trying to find ways to handle water after it has seeped through the foundation.
Due to the various factors that might be involved, a special program or plan of attack will need to be developed for each situation.
The best way to determine the cause of water penetration is to walk around the perimeter of your house after it has been raining heavily for several hours. Notice how the gutters and downspouts are handling the roof run-off. If there are no gutters, check to see if the roof run-off is accumulating at the foundation. Also check to see if there is a flow of surface water toward the house.
Armed with this basic information possible solutions can be developed. We suggest you start with the following inexpensive remedies first:
- Add gutters and downspouts if lacking and if roof run-off doesn't drain freely away from the foundation.
- Clean out gutters and downspouts; repair leaking sections.
- Make sure downspouts terminate onto splash blocks or run into a leader that extends away from the foundation. If needed, pipe water to the curb or a storm sewer, if acceptable.
- Make sure the overall site and foundation grading is sloped away from the house and work on providing a good stand of grass. If necessary, add drains or swales on sloping areas to divert water flow away.
- If the foundation grading is flat or slopes toward the house, raise the grade (but not too close to the siding) so that it slopes 1-2 inches per foot for at least 3 feet from the foundation. Check any catch basins or underground drain lines, clean out as needed ,and confirm water flow.
- Be certain that window wells are clean, drain quickly, and if needed have a plastic covers to shed water. A recessed basement entryway should have a working drain and, if necessary, a cover.
- If the driveway is below street level, installing a berm at the street will help minimize street run-off.
- If your basement tends to be damp, add a portable dehumidifier and run it when needed (which may be year round).
- If there is significant seepage, install a sump pit at the lowest level of the basement and pipe the discharge out and away from the foundation. If a pump exists, make sure it is set and working properly and discharges the water to a suitable point.
If the water penetration conditions subside after these steps, and seem to hold up after a full year of normal weather conditions, then a coat of quality waterproofing paint can be applied to interior foundation walls. First clean the walls of efflorescence, mildew, peeling paint, etc. and seal all joints, cracks and holes with a waterproof sealant. This paint coating will not hold back water, but should help control dampness.
The above steps should help improve most typical water penetration conditions. However, if the house is on the side of a hill, or water ponding occurs due to poor surface or soil drainage or if there is a chronic water table problem, professional help will be required. Major work may include installing exterior and/or interior drains around the perimeter of the foundation. When contemplating work by a contractor, always obtain several estimates so that an informed decision can be made.