Wet Basement Primer | |
Ninety-five% of basement water problems are unrelated to the water table (ground water), but rather are caused by improper handling of surface water, primarily runoff from roofs. And in 95% of these cases, the best approach is to direct water away. These are the approaches covered here. Interior diversion systems might be tried next Your last resort should be to attempt to seal basement walls. Roof Water Problems/Solutions Go outside in a heavy rains to evaluate your gutter system: Look for overflows or leaks (especially at connections); see if water empties near the foundation. Make any of the following corrections as seem appropriate. - Clean gutters - Install gutters unless heavy snow and ice make them impractical in your area. If your present system is inadequate, install a larger gutter or add downspouts to boost the water-carrying capacity. Replace any damaged components. - Refit any failed gutter system connections. Use aluminum rivets to secure them: Drill 1/8 in.-dia holes through connecting pieces, insert rivet in Pop-Rivet tool and into drilled hole; and pull lever. - After cleaning the surfaces well, seal joints and holes with a top quality gutter sealant. - Direct downspout water away from foundation. Add a length of horizontal downspout to the bottom of the existing downspout that extends at least 5-6 ft.; and, if possible, provide a rock or concrete splash block at the end to limit erosion. Or, better yet, dig a trench and set in a length of 4 in. PVC drain pipe with a downspout adapter at the house end and direct the other end into a catch basin/surface bubbler (a home center/landscaping outlet product) buried into the ground; or direct pipe to a garbage-can size drywell. Perforate a plastic garbage can full of holes, set it in a hole and direct pitched drain pipe into the top. Fill the can with gravel and add gravel around the outside, too; cover with landscape filter fabric (available at garden centers) or the above-mentioned pond liner; and then cover with soil and replant. - If you can't install gutters, create a surface drain to collect and direct water away. Here's one good system: dig a 1 ft.-wide x 6 in.-deep trough at the roof drip line; line it with sheet-rubber lined (a pond lining material is excellent) to contain the water; lay a 4 in.-dia. perforated PVC drain pipe in the bottom (holes down) to carry water away; and cover it with gravel. At several points (every 20-30 in. or so and at the pipes low points) add a T-fitting and a pipe that extends 10 feet away from the foundation to a catch basin and surface bubbler, or to a drywell (see above). Grade-related Problems/Solutions When excavated earth around a foundation is backfilled, a certain amount of settling is natural and should be anticipated. Excessive settling is due to using improper materials or procedures. The backfilled soil is almost always more porous than the surrounding, undisturbed soil. Water dripping from roofs can create gullies that prevent water from draining away from the foundation. In very cold climates, gaps that occur between the frozen earth and the wall (unavoidable) make any grading problems (avoidable) ten-fold more serious. - Scrape away loamy topsoil; then add soil or rearrange dirt as needed. The grade should slope away at least 1 inch/foot for a distance of 3 ft. minimum but preferably 10 ft.; and leave at least 8 in. of foundation exposed under siding, more in snowy climates. If this involves a great deal or work and transplanting, consider have the work done by a professional excavator/landscaper. - If a window well has settled allowing water to enter at the top, extend the well and regrade by adding tamped soil near the foundation. Use same-size metal extensions overlapped and screwed to the existing; or stand pressure-treated pieces or lumber or brick or flagstone "soldiers" on end around the well perimeter, burying about half their length. And make sure that the bottoms of wells are not clogged with dirt or leaves which inhibits proper drainage away from the foundation. Some Landscaping Tips - Plant grass next to the foundation and locate planting beds 5-6 ft. away from the building; or plant groundcover that has a thick root system around foundation plantings rather than using mulch which holds water in. The root systems draw water out of the soil. - Look for and fill any animal holes by foundations. Construction-related Problems/Solutions - Patios, porches and driveways should be pitched away from the house. If they are not, they should be replaced, recapped or "mudjacked" (all professional services). Joints at the house should have been flashed at installation, or be sealed with caulk. Polysulfide caulks are excellent. The caulking task: create a 1/4-1/2-in.-wide channel (if not present); carefully clean the joint surfaces; pack in a backing rod (strips of foam or fiberglass insulation) to within a 1/2 in. of the surface; fill the joint with caulk; and tool it with a stick or wetted rubber-gloved finger. - Clogged foundation drains. Foundation drains consist of a drain pipe that is usually set in gravel at the base of the foundation wall with outlets leading away from the foundation. The gravel bed should be protected (to some degree) from dirt infiltration. The pipes drain to "daylight" (an above-grade opening), a drywell or to a sump (collection point) where water is, in turn, pumped to daylight or a large drywell. If cleanouts (access pipes that allow auguring, flushing and other cleaning) are provided, you can attempt to flush the system yourself by inserting a garden hose, but typically it's a job for a professional. If no cleanouts are provided, you'll have to excavate at several corners to access the pipes for cleaning. Or replace the entire system; since that option involves extensive excavation and relandscaping, it is rarely chosen. - Make sure a sump pump pipe doesn't discharge too close to the foundation. - Not all problems are related to surface water. High humidity causes condensation on basement walls and floors. To limit it, insulate cold water pipes or AC ducts; vent clothes dryers and bathrooms with showers outdoors; ventilate as much as possible, run dehumidifiers in the summer months, or air condition finished basements to dry the air. Written by Roy Barnhart Copyright HouseNet, Inc. |