Exterior Basement waterproofing

My Basement Leaks When It Rains – Why and What Do I Do?

Unfortunately for many homeowners, wet basements, especially after a heavy rain or large thaw is a common occurrence.  If you have an older home, you are even more likely to experience this issue.  You may notice a damp, musty smell in the basement or you may notice signs of water stains on the walls and/or floor.  It is also possible to even see puddles of water. If you are having water in the basement after rain, don’t panic as it is fixable! However, you should act quickly to prevent the problem from worsening and creating additional issues to your basement and the foundation of your home.

In order to fix the issue, the cause first needs to be accurately determined. Below are listed some of the leading causes of water leaking into the basement after heavy rainfall.


  1. Hydrostatic pressure. This is the buildup of pressure from water which pushes against the foundation floor and walls.  After a heavy rainfall or a large amount of thaw, the soil around the foundation becomes saturated with water. Water is extremely heavy, approximately 62 pounds per cubic foot. The weight of all this excess water creates an immense amount of pressure on the foundation and the water will be forced into the basement through a point of least resistance.  It may come through cracks in the walls or floor or mortar joints.  Commonly, it will seep through the wall-floor joints which is where the wall and floor meet.
  2. Lateral Pressure. Soil around the foundation usually will absorb more water, especially if you have a newer home the soil will be looser from the excavation and the looser the soil the more water it will hold.  If you have drainage issues around the home the soil will expand and create lateral pressure against the foundation which can damage it and force water inside.  Clogged up gutters contribute to this problem, so it is important to ensure that they are kept clear of debris.  They should be cleared out a couple of times a year to prevent the overflow saturating the soil by the foundation.  It is also necessary to ensure that the downspout is extended away from the foundation.  About 6 feet away from the foundation is a good distance.
  1. Window well issues. If window wells are improperly installed or become clogged, they can hold water and eventually leak.  This type of basement leak is easily identified because water will be coming through the window frames. You can check for clogs by testing it with a garden hose and seeing how quickly the water drains out of the window well.  You should regularly check them for debris and clean out any buildup to avoid them becoming clogged.
  2. Damage to foundation. Foundations will naturally deteriorate over time. If you have an older home, it can be expected to have some holes or cracking.  However, you should have these fixed as soon as you notice them so that the foundation problems do not become worse.
  3. The grading is the slope around your home.  Proper grading is one natural way to help keep the water away from your foundation thereby reducing the risk of leaks.  If you have proper grading, gravity will help, and the water will run away from your home instead of towards it.

If you have a home with a leaky basement, you can count on Waterpro Master.  With many years of experience in basement waterproofing in the Toronto and the GTA, we guarantee to find the root of your problem and come up with an effective waterproofing solution!

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