Is your basement wet? Are you thinking about calling a basement-waterproofing contractor?
Many contractors will propose installation of expensive interior drainage systems — even if you don't need one — when most moisture problems can be solved through less-expensive means. You're more likely to get good results — and save a lot of money — by exploring other possible solutions and hiring a basement-waterproofing contractor only if absolutely needed. If your home was built within the last few years, check the builder's warranty for clauses on seepage.
Most basements get wet when rainwater runs toward the walls of houses from roofs, yards, and driveways. So your first step is to force it to run away from your home.
Start by cleaning your gutters, repairing holes, and making sure they slope toward downspouts and have not come loose from the house, allowing water to fall directly from the roof to the ground. Test downspouts to make sure they spill water at least four feet from the house.
You can extend downspouts for less than $15 each; gutter repairs are more expensive. But these improvements are worth the price, even if they do not fully solve your water problem.
The next step is to inspect the soil around your house and regrade it, if necessary. This is a job you can do yourself, or you can call in a landscaper. The earth around your house should slope at least one inch per foot going away from the house for about six to eight feet out. The grading should consist of fill soil with a clay content of 20 to 30 percent. Don't use sandy soil or soil containing a lot of organic matter; it will not shed water adequately.
Before adding dirt around your foundation, rake out all old mulch, leaves, and ground cover. If they are filled over, they will create a shelf that catches water.
A grading solution obviously has important advantages. It costs little — dirt, after all, is cheap — it requires no great skill, and it should move enough water away to prevent serious harm.
If portions of your yard slope toward your house, you may have to cut a shallow ditch, or swale, to divert water before it reaches the house. A swale is a U-shaped ditch dug perpendicular to the water flow. Like regrading, it's a fairly simple job.
Regrading or diverting surface water will solve most basement-moisture problems, but it may not always be the best approach. It may cost more than other solutions — for instance, if you have to rebuild an elaborate patio that slants toward your house, or if you have to redo extensive landscaping. Furthermore, grading is not a sure cure for leakage problems; Water may be penetrating your basement from places that originate well away from your house. And sometimes regrading is a relatively frail solution; a little careless digging in your garden may produce a new source of leakage just after you have installed a home theater in your basement.
If regrading and other surface-drainage improvements don't solve the problem, more drastic —and expensive — solutions await.
For most homes, the next best approach is to waterproof walls from the outside. To do this, a trench is dug to the depth of the footings of affected walls. Drainage pipe installed at the bottom of the trench to collect water that seeps from above carries it to a part of your yard away from your home or into a drainage pit. The exterior walls are re-parged and a vapor barrier added. The trench is filled with soil that is tamped down, and the surface area is regraded to improve surface drainage.
Excavating and waterproofing from the outside might be more expensive than installing an interior drainage system. But Checkbook's view is that, unlike interior systems, this will actually solve the underlying problem by diverting water away from walls, rather than simply managing water that enters the home.
If you need to hire a contractor, meet with and obtain proposals from several. Many landscaping companies specialize in drainage work. You can get some insight into a company's performance by checking the ratings and comments posted by area consumers in the "Basement Waterproofing" and "Landscapers" sections at Checkbook.org. Through special arrangement with the Inquirer, you can access ratings in these categories free of charge until June 30 by using this link: www.checkbook.org/inquirer/wet-basements.