How to Prevent Mold Growth on Your Basement Ceiling

Mold growth shows on concrete.
  • 1-2 hours
  • Beginner
  • 30-200
What You'll Need
Air conditioner
Humidity monitor
What You'll Need
Air conditioner
Humidity monitor

The basement ceiling is one of the premier spots to find mold in your house because mold forms in cold, damp areas. The lack of ventilation and sunlight that’s common in basement spaces provides a perfect environment for mold growth; however, that doesn't mean that you should resign yourself to having a moldy ceiling. Follow these steps to eliminate mold growth.

Step 1 – Control Moisture

The key to mold prevention is maintaining a dry basement. If you suspect that you have mold, you need to find anything that could be causing moisture to form or pool in the basement. Check any carpeting and all of the perimeter walls. If you find any areas of water ingress, you must ensure that you deal with them properly to prevent the mold from returning.

Step 2 – Circulate Air

Open the windows to increase air circulation. If you don't have windows, then use an air conditioner or a dehumidifier to dry the area. Portable units are available from shops and rental companies if you don't want to install a permanent unit.

Step 3 – Fix Any Leaks From Above

The most common place to find mold on a basement ceiling is under areas where water is frequently used in the house above, such as the kitchen or bathroom. If you have a problem with leaks from any of the water pipes or appliances in your home, check the basement ceiling periodically for mold.

Inspect and replace any damaged insulation materials in the floor and ceiling cavity. Leaving damp materials will encourage mold growth, which will typically begin growing within four days, but if it is in the cavity, you may not notice it until much later. Install exhaust fans in your bathrooms and kitchen to reduce the moisture that accumulates in those rooms.

Step 4 – Monitor Humidity

Hardware stores stock humidity monitors that you can install in your basement to track the ambient moisture. Ideally, you should keep the humidity level below 60% to prevent mold growth.

Step 5 – Take Care of External Water

If your basement ceiling is at ground level, then standing water in the ground surrounding the house is another risk. Make sure that all downspouts from gutters are in good condition and that they expel water into a drain, not directly into the soil around your home.

If you have a driveway or a concrete slab at the side of your house, ensure that they are on a slight slope (at least one inch for every 10 feet of width) so that any rainfall will run away from the walls rather than pooling around the house.

Step 6 - Insulate Pipes

Insulate the pipes which run across your basement ceiling to prevent condensation from forming on them in the summer months. Check the point where the pipe enters the basement from above for signs of mold.