Why Is There Water In My Basement After Rain?

11/5/2020 (Permalink)

Figuring out why your basement floods every time it rains can be a challenge.

Finding your basement floor covered or damp with water after it rains can leave you scratching your head to figure out how it's getting there. When water is entering your basement where the wall meets the floor every time it rains, you're likely struggling with a hydrostatic pressure issue, which we will explain here.

Causes of Water Coming in Basement Where Wall Meets Floor

Hydrostatic Pressure

Hydrostatic pressure refers to water pressure. When the ground around your basement is saturated with water, it exerts pressure on the foundation and walls of your basement. One cubic foot of water weighs about 60 pounds - so when the ground outside your home is saturated, you may have thousand of pounds of water pressure looking for a way past your foundation walls.

Eventually, this hydrostatic pressure against your foundation will allow water to find it's way in and cause some sort of basement leak most likely due to the structure your basement, which we will review next.

Gap Between Basement Wall and Floor

This gap is commonly referred to as the cove joint, and is common in many basements. When your basement is dug out to build your home, a large slab of of poured concrete was made to support your home. This must dry before more concrete is poured, and since new concrete does not bond with the old you are left with a small gap, or the 'cove joint' where water under pressure can get through the wall.

Since most basements have cove joints (the gap between your basement wall and floor), things such as a high water table, clogged or failed drainage systems, and improper draining of surface water from your home can cause water to come in the basement after rain.

Preventing Water In Your Basement After Rain

When it comes to cove joints, hydrostatic pressure, and wanting to keep your basement dry and clear of water damage - there is a struggle. There are solutions to your basement water problems, but the permanent solutions can run upwards of thousands of dollars. Below are ways to prevent water in your basement after rain in order of cost:

• Navigate water away from the foundation - Do this by extending your gutters and downspouts and inspecting the ground around your foundation for any areas that slope towards your home rather than away. Then, take steps to raise the slope away from your home with sand or clay and top with gravel or woodchips.
• Clean your gutters - Clogged gutters don't efficiently allow water to navigate away from your home, and may instead cause water to flow directly down the siding of your home and along the foundation wall. This will allow water to collect in the ground and exert pressure on the walls of your basement.
• Waterproof your basement - There are many ways to accomplish this, but most should be done by a professional with the average cost ranging from $3,000-$15,000. Depending on your basement and your needs, you may install a sump pump, interior drain tile, exterior drain tile, or general basement waterproofing without a drainage system.