Moisture is second only to framing when it comes to basement remodeling projects. Because the basement is below ground level, it already has two strikes against it. If the home has not been properly designed, remodeling the basement is very difficult if any moisture is present.
Nothing is worse than doing a fine job of remodeling only to have spots appear on the drywall shortly thereafter. Not only is it expensive to replace the drywall, but mold growth is also inevitable. Because some homes are built on a clay substrate, other problems can arise. Here, we discuss moisture problems in a basement remodel.
Proper Preparation Is A Must
There is no such thing as a dry basement. Even if you find no evidence of water stains or dampness, the very nature of the construction allows moisture to accumulate because the basement is below ground level.
Even if the basement appears to be dry, there is still moisture in the form of water vapor. Fasten a 24-square inch sheet of plastic on the basement wall. Remove it after several days and note the condition of the wall. If it is dry under the plastic, then water vapor is present. If it's wet, then water is seeping through the walls from the exterior.
Inspect your basement. If you are unsure what to look for, ask a contractor to assist you. Carry a strong flashlight for deeply shadowed areas. Look for water spots on the wall, as well as mold. Look for overhead pipes that may have a slow drip. You don't want to cover the pipes only to discover later that they are seeping through ceiling tiles or plaster ceilings.
You're way ahead of the game if you have poured concrete walls in your basement. Water collects in the 3 holes of the cement block; it is only a matter of time before moisture seeps through the wall. Improper drainage techniques around the perimeter of the home occur.
Check the concrete blocks thoroughly. If there is any sign of mold or water stain, water is likely to be standing in the blocks. Even with poured walls, there is an introduction of water vapor due to the very nature of concrete.
Fixing Drainage Issues
Several methods are available to fix the drainage issues. The easiest to accomplish happen on the exterior of the home. One method is rerouting the drain spout so that does not empty along the perimeter of the home.
Careful grading must be built to ensure water runoff, and reworking the exterior runoff system is a must if it was not originally done properly. Proper grading ideally should slope down 10-feet from the house and have a drop of at least 6-inches.
Contractors recommend that if you live in areas with high clay content, such as in Colorado, that you do not plant large flower beds along perimeter walls. In an arid climate, these beds are watered frequently, and the composition of the soil makes for leakage. They instead recommend building a deep gravel bed and planting juniper trees.
Install French drains in problem zones. French drains are trenches installed around the exterior of the home to provide proper drainage. Many people think a French drain is installed with pipe, but the real French drain uses gravel.
Be mindful not to install a French drain that will flood your neighbor's property. In extreme situations, the French drain can be installed on the basement floor. Plan on spending a good sum to have that done. Instructions for building a French drain can be found online.
Once you are sure that drainage issues are handled, seal the interior walls of the basement. If you find black stains indicating mold, use muriatic acid to clean them and spray them with a hose before installing proper ventilation.
Repeat this process several times. Once the walls are clean, they can be sealed in several ways. Drylok is a common sealant, but a more superior product is Xypex. Drylok is a latex-based waterproofer, while Xypex, which is more expensive and is only activated upon making contact with water.
Always remember that a basement is never dry. You can remove water vapor with a dehumidifier, and ensure that proper ventilation is in place. New construction is much tighter than that of an older home, so be sure to provide proper ventilation to the interior. Always deal with moisture before you begin a basement remodel project.