A Leaking Concrete Floor

Causes of Concrete Floor Leaks

• Condensation on concrete floors can occur when variations in indoor and outdoor temperatures cause moisture to form on the surface. Moisture can also migrate from the ground at the perimeter of the concrete or through the concrete materials, which contain large amounts of moisture. Leaks in concrete can originate in plumbing that is installed in or under the concrete flooring. Moisture can also seep in through foundation joints from the outside after heavy rains that saturate the soil around foundation walls, according to the Iowa State University website. These problems can be mitigated with a number of techniques to help keep your concrete surfaced indoor areas dry and comfortable.

Proper Concrete Installation

• Using the right materials will help prevent leaking and seepage that can often occur in concrete surfaces. Use a high-quality concrete and limit the amount of water in the mixture. Excessive water in the concrete mix decreases the strength of the finished product, causing it to shrink and crack upon drying. If potential water seepage is anticipated in your flooring, use an insulating concrete material, which contains aggregate that reduces the amount of condensation of the flooring. This type of concrete must be continuous and connect with insulation in the walls surrounding the floor. Providing control joints in the concrete flooring allows for adequate expansion and contraction that reduces cracking and leak problems.

Moisture Barriers

• Adding a moisture barrier on the ground before pouring the concrete floor will help reduce condensation and seepage from the soil. You can also build an additional flooring surface above the concrete floor, adding rigid insulation between the concrete and the flooring. This action will help control moisture and keep the upper floor surface warm.

Providing Good External Drainage

• To prevent leaking problems on your concrete flooring, ensure that the external drainage allows adequate water flow away from the foundation and concrete surfaces. Building up the soil around foundations will draw water away from concrete walls and floors. French drains that use 4-inch plastic pipe covered with gravel also allow water flow away from concrete surfaces for a drier environment.

Sealing Concrete Floors

• Concrete sealers that are available on the market help limit the amount of water that leaches up through capillary action from the ground under the flooring. This method will not prevent condensation, however. Further measures to control humidity in the area, such as proper ventilation and use of a dehumidifier, may be necessary.