Should it be a surprise that water seeps into basements? What is a basement? It’s a hole in the ground with walls and sometimes a floor. We have to hope the ground has water in it or we would all be in trouble. This being the case with basements and the earth they are encased in, what do we expect? Virtually all basements are susceptible to water seepage and most do get some type of moisture penetration whether the homeowner realizes it or not. There are several types of water seepage found in basements; some are as minor as humidity and others cause significant damage to property. Water seepage originates from various sources. Each home is different. Some homes have block foundations, some have stone foundations, and some have poured concrete foundations. The manner in which a house is placed on the property and the type of soil around the house varies from neighborhood to neighborhood. All these things are factors in whether or not water seepage is going to be a problem. In this newsletter we hope to address some of the causes of basement water seepage and provide some of the possible solutions to those problems. Some you may want to attempt yourself!

WHAT TO LOOK FOR:

During dry times it is not always possible to determine the extent of water seepage problems or the existence of unseen water problems that may appear during wetter seasons. However, if a basement has not been altered by fresh paint or other covering methods, there is typically some evidence of where, and to what degree, water may have entered. Water stains on walls, floors, furniture, and storage, the location of the stains and how wide spread the stains are can often clue you in as to howmuch water has penetrated. Of course, it does not always tell you the frequency of water seepage, if the water was from an exterior source, from a plumbing leak, or a defective boiler or water heater. Obviously the best way to determine the problem is to actually see water seepage as it happens. This makes evaluating the source, the extent of the problem, and possible solution much, much easier to determine.

Efflorescence is a white powdery film that forms on the surface of concrete or masonry when salts in these materials are dissolved by moisture passing through. The moisture evaporates at the surface leaving the film.

Efflorescence can be reduced and sometimes eliminated by two fairly easy remedies. The ground around the foundation should slope down and away from the house with about one inch of pitch per foot for the first five feet. For homes with foundation windows close to the grade level, window wells will be needed in order to raise the grade to a proper slope. Downspouts should also be extended a few feet from the foundation to shed the water away as much as possible.

Efflorescence can be cleaned with a mild detergent or special chemical cleaners found at most building suppliers. If waterproofing paint is to be used, as much efflorescence as possible should be eliminated. If it is not, the efflorescence from behind the paint can cause spalling or flaking.

Condensation is the result of warm, moist air coming in contact with cooler objects. If you find moisture on your basement walls, there is a simple test that can determine if it is condensation or from an exterior source. Tape a one-foot square piece of aluminum foil to the wall, making sure all sides are airtight. Remove the foil after two days; if the moisture is on the outside of the foil it is condensation. If it is on the inside of the foil, it is from an exterior source. Properly vented clothes dryers and basement bathrooms will reduce condensation. Wrapping cold water pipes and storage tanks for wells with insulation will reduce condensation on these objects. The use of a dehumidifier in the summer months is recommended. After these steps a coat or two of waterproofing cement paint may also be useful. Properly vented crawl spaces will reduce the amount of moisture in these areas. Crawl spaces should be vented during the summer months and have a vapor barrier or concrete floor to reduce condensation.
 

Surface water allowed to seep into the ground next to the foundation can find its way into the house through cracks, tie holes, and seams between the foundation and basement slab, this results in problems such as efflorescence, small puddles, or even flooded basements. With drier soil next to the foundation, it is less likely that seepage will occur. Proper grade slope and downspout extensions are the best ways to reduce the chance of seepage from surface water. Grade slope can be seen in diagrams 1

Downspout systems like the one shown in diagram 2 can be purchased in local home stores. The type of soil around the foundation also determines the importance of directing the water away from the foundation. Soil with a high clay content will stay wet longer, while sandy soil will allow the water to pass through more quickly into the water table. If the grade is already too high to raise sufficiently without coming in contact with the siding, a surface drain may be needed to divert the water. Patching all cracks, tie holes and seams with hydraulic cement is also recommended to prevent water seepage.

Underground water and water tables:

If all the steps mentioned above have been taken and there is still water seepage, it may be from underground water or a rising water table. The typical methods for directing underground water and water tables is the use of a French (footing) drain, or sump pit with a sump pump (diagram 3), or both. A footing drain consists of a perforated pipe installed in a bed of crushed stone around the perimeter of the inside or outside of the

 foundation footing; this can be seen in diagram

1. These drains will fill with ground water or the rising water table and empty into a sump pit in the basement; it will then be pumped to the exterior away from the house. Some homes will not need a sump pit. The drains will extend at a level grade underground until they reach a section of the property with a sufficiently sloping grade to allow the pipe to surface and empty the water away from the house.

Installing footing drains after original construction is no small job and can be costly. Interior above-slab systems have been developed to catch the seepage and direct it to the sump pit (see diagram 4). Until recently these types of systems could only be obtained and installed through professional waterproofing companies. Now there are systems that a handy homeowner can purchase from local home stores and install themselves.

WHEN TO GO WITH THE PROS:

The cause of even simple water problems is sometimes difficult to determine. Although many water problems may be able to be eliminated by a handy homeowner, professional application and repairs may be needed. If you are unsure of your own skills for diagnosing and repairing the problem, please call a professional.

There are many types of water problems and many types of solutions to those problems. Professional applications typically come with a warrantee that their application will work. While this may be more costly upfront, it can eliminate much of trial and error on your part. It may even save you money in the long run. There is no guarantee that your efforts will solve the problem and you may end up needing professional help anyway. You are then out your repair cost in addition to the pro’s fee. So, unless you are confident and willing to put in the effort, go with a pro.

The information contained on this page is not exhaustive and is meant to be only an overview.  For complete documentation on this subject please contact local or State heath officials.