Tips to Prevent Basement Flooding
Your Sump Pump is your First Line of Defense in protecting your Basement from Flooding. Your homes foundation is surrounded by weeping tile which will collect any ground water that is present at the lower portion of your foundation. The weeping tile, which is surrounded by stone, will collect any water and allow it to drain into your sump pit where your sump pump will direct it to the exterior of your home. Some homes in larger cities will not have a pump but the drain will drain directly into the storm sewer. Barrie for example does not have a storm sewer system that will allow this. If you live in an area which has a high water table it would be advisable to have a back up sump pump and a battery back up to protect your home during a power outage. A newer sump pump system runs off your homes water supply and is often used as a back up as your water supply works during power outages.
Gutters and Downspouts collect a lot of water during a rain storm. It is estimated that one inch of rain on an average 2,000 sq ft home will produce approximately 1,100 gallons of water. Your downspout should be directing their water discharge at least 6 feet away from your foundation. In Barrie most subdivision homes have a swale located between homes that will direct water towards the street or backyard in some instances. I always recommend to my Home Inspection clients that they grab their umbrella during a heave rain and go outside and identify any areas where water is not properly draining away from their home.
Landscaping and Drainage have a huge impact on what happens to water from rain or snow melting. Ideally your homes grading should slope down 6 inches for every 10 feet away from your foundation. Older homes may have had top soil added or even worse, planters built against the foundation which will trap and collect any water in that area. Many home which have a sidewalk along foundation will notice that the sidewalk slopes towards the house which will direct water against foundation. Soil beside a foundation will typically sink as it was never compacted when house was built.
Seal Exterior Openings with exterior rated caulking. Some home owners use open cell spray foam which will not stop the penetration of moisture. For large openings I always recommend using foam backer to block opening and then sealing with caulking or other water proof sealant. Check your air conditioner, electrical, water pipe or exhaust vent openings to ensure that they are adequately sealed. Caulking does not last forever so your should check your exterior penetrations annually.
Monitor Foundation Cracks for expansion over time. Most homes will have minor foundation cracks in the concrete. Concrete is a porous product and water will seep through if allowed to collect around your home. A new homes Tarion warranty will only cover cracks that are over 4 mm in size or leaking water. Any smaller cracks, usually identified as shrinkage cracks, are not covered by warranty. Any horizontal cracks in your foundation could be an indication of structural movement etc and should be examined by a foundation specialist prior to purchasing. Some homes foundation were not installed square and can be identified by examining the starter row of brick, many homes will have overhanging brick to compensate for foundation not being squared.
Sewer Backup Prevention is common in big cities like Toronto but is rare in cities like Barrie, Alliston or Orillia. Some newer homes may have a Back Flow Prevention Valve installed, buy most home typically do not have one installed. Most insurance companies will ask if your new home has a Sewage Backup Preventor Valve installed.
Insurance Coverage should be updated if you renovate or finish your basement. Check with your insurance company to identify what kind of flooding would be covered. Some insurance companies will only cover basement flooding if cause by mechanical failure for example. This knowledge will give you piece of mind.