Top of foundation
When water is seen in the basement, most homeowners would assume that it got inside through cracks in the wall or floor, or through the cove joint (where the basement wall meets the floor). However, sometimes water is able to get inside by going over the top of the foundation. This is often seen on homes that already have some kind of lawn grading issue. A lawn has grading problems if water is able to pool up next to the foundation wall, or if it can be seen forming puddles in low-lying areas of the lawn.
When the moisture rests up against the foundation, it actually puts a lot of pressure on the walls. It will eventually break through any caulking or seal that is in place between the top of your foundation and the area where your siding starts. When this happens, the water will spill inside over the top of the foundation and run down your basement walls. This can be either an above-grade or below-grade problem.
Above-Grade and Below-Grade Moisture Problems
If a problem is below-grade, then the spillover joint (where the top of the foundation meets the main floor) will be saturated with moisture every time it rains. When you have an above-grade moisture problem, then the water is able to get inside at ground level.
One simple test you can do on your own to determine what kind of problem you have is known as the water test. On a dry day, lay a hose on the ground and run it for 5-10 minutes. If moisture is seen in your basement, then it is likely a below-grade problem. A waterproofing professional will be able to perform more complex tests, but this is a good starting point.
Warning Signs of Water Getting in Over the Top of the Foundation
When you notice any of the following, then moisture is getting into your home via the area where the top of the foundation meets the main floor to your home:
- Water is seen dripping down the walls, starting at the very top of the foundation.
- Water is often seen in puddles next to the foundation wall after a heavy rain (this could also be a grading problem).
- Stains can be seen on the basement walls.
- Mold is seen growing on the damaged areas of the wall where moisture repeatedly runs down.
- Puddles are seen forming on the basement floor next to the wall and cove joint (where the wall meets the floor).
Often times, the solution to this kind of problem involves first fixing any grading or drainage issues that the lawn has, and this will involve the installation of French drains and exterior waterproofing membranes. Inside of the home, the spillover joint will need to be repaired. This area is likely very damaged from all of the moisture that has leaked inside over the months or years when the problem first started. Also, sometimes the grade level surrounding a home will need to be lowered so that water can't easily get in over the top of the foundation wall.