Often the source of water in your basement cannot be easily identified. In some cases it is difficult to determine whether the water is coming from the outside or from condensation on the inside. This is resolved as follows: tape a twelve-inch square of aluminum foil to the damp wall area. Seal all four sides of the aluminum foil as tightly as possible. If in a couple of days, the outside is wet, it is condensation. A dehumidifier in the basement near that wall will help solve that problem.

On the other hand, if they side of the foil that was against the wall is wet, it is seepage. This may be more difficult to overcome. It may be necessary to excavate and seal the wall, or a drainage system may be needed to carry the water away from the home.

For persistent problems, contractors use a variety of alternative methods; redirecting water away from the foundation or into a drainage or pumping system; installing an interior drainage system on the inner side of the foundation; applying waterproofing compounds to the interior walls (which may be effective in cases in which there is mild seepage); injecting waterproofing substances into the exterior (between the soil and the wall), but this "has not demonstrated a satisfactory performance and is not acceptable under HUD standards." An extreme measure is excavation by exposing the basement walls and treating them to make them watertight.

It is important to hire a knowledgeable and competent contractor to evaluate your problem. The BBB suggests the following:

• Obtain written estimates from at least three contractors before selecting one.
• Check whether the company is currently insured (liability & workers compensation), and if applicable, what permits and/or licenses are required to perform the work.
• How are employees trained? What continuing professional education do employees receive? Is the company certified by trade organizations such as the National Association of Waterproofing Contractors?
• Obtain several customer references, and go and inspect the work.
• Find out how long the company has been in business. What is their warranty or guarantee?
• NYS law requires that if a deposit is paid, and the job is more than $500 - and the work isn't completed in 10 days of the deposit - the deposit is to be placed into an escrow account.
• A contract should have a cancellation clause, job description, date of essence and progress payments.
• Never, ever pay for the full job upfront - expect to place a deposit of 1/4 to 1/3 down.
• Check the Better Business Bureau reliability reports.

Courtesy of BBB - The Better Business Bureau. Serving Buffalo, Niagara Falls, Rochester, Albany and Syracuse regions