Printed: Thursday, September 02, 2010

Basement flooding can be a problem in some homes, and there are steps to take to minimize potential damage.  But since a flooded basement can result from a number of things, there is no single method for prevention.  The most important things are to determine:
 
1) When is the basement flooding?
2) Where is the basement flooding? 
 
For example, does the basement flood every year at approximately the same time (such as in the spring during heavy snow melting) or does the basement flood during random intervals?  Also, is the basement flooding due to seepage through a wall, multiple walls, through a floor drain, etc?
 
Once you have identified the source of the water loss, determine the appropriate solution for preventing water from entering the basement.  For example, if water is entering the basement near the top of the wall in one location, it may be due to something like an improperly sloped landscape (toward the house) or a gutter/downspout system that is draining water toward the foundation.  These problems are fairly easy and cost effective for the homeowner to fix by extending and re-directing the downspouts and/or reshaping the landscaping around the foundation of the home. 
 
Also, if water is coming though a specific location in a wall, this problem may be remedied by caulking cracks on the interior of the home where water is penetrating the wall. 

If the entire wall is damp, or water is entering through multiple wall surfaces, it may be a sign of a faulty or missing water proofing membrane.  To remedy this problem, the soil around the foundation needs to be removed and a waterproofing membrane should be installed by a licensed and bonded certified contractor. 

Internal sealants that are painted on interior surface of basement walls may also be considered, but this assumes the wall is unfinished.  It’s not an option for finished basement walls.  These products also require constant maintenance or they will stop working.  Just like you have to maintain your tub/shower caulking, basement sealants/caulks must be maintained as well. 

 If the water appears to be entering the home near the foundation or through a floor drain, the repairs become more extensive.  One solution is to install a “French Drainage” system around the perimeter of the home, or at least in areas subject to frequent flooding.  This involves removing the soil around the perimeter of the home, waterproofing the foundation wall with a waterproofing membrane (if necessary), installing a French Drain at the base of the foundation (this drain also has to have a method for diverting the water to either the primary storm drainage system, retention pond, etc) and finally backfilling the area with gravel to provide adequate drainage to the French Drain. 
 
A second solution would involve installing a sump pump in the home.  A sump pump is generally installed in a “sump pit” beneath the home’s foundation, so this requires demolition of a portion of the basement floor to install the sump pump/pit.  Also, a sump pump in itself will not solve all of the drainage problems.  To be effective, the sump pump needs to be hooked up to a drainage system, usually installed around the perimeter of the basement foundation, or at least in areas subject to repeated flooding.  Because this is installed at the perimeter of the foundation, the flooring in this area will also face demolition to install the drainage system. 
 
It is also highly recommended that all homeowners installing new sump pump systems, as well as those with existing systems, have a battery backup system for their sump pump.  If the power goes out (as it often does during a heavy storm) the sump will not operate unless battery backup is available. 

Note: Sump pumps should be tested at least once of year, preferably in the early spring once things have begun to thaw.  Also, if you know a storm is coming and your basement frequently floods, test the system in advance of the storm.  To test the system, make sure the sump pit does not contain any debris that will clog the sump’s inlet pipe.  Also make sure the outlet pipe is not frozen shut.  Pour water into the sump pit until the sump turns on (about 5 gallons of water).  If the sump does not turn on, contact a professional to diagnose the problem.  
 
Even though it’s more expensive, it’s a wise investment to protect a home from the outside if it frequently experiences water problems.