How to control moisture in your home or business
Too much moisture in a home or business can cause discomfort. Plus it encourages mold, rot, and bacteria, and erodes the durability of a structure. Take the following steps if you experience damp-smelling rooms, find mold or mildew on walls, or see condensation on windows and ceilings.
Step 1 – Find the moisture
Homes and businesses can have many sources of moisture, among them bathrooms, kitchens, basements, and clothes dryers. Use a relative humidity (RH) meter to measure different areas of your home. A comfortable RH level is between 40 and 50%—although in winter, you may want it below 40% to avoid condensation on windows.
Check humidity levels to pinpoint trouble spots
Look for condensation, wood rot, mold, and peeling paint
Check for leaks in your basement, roof and attic, crawl spaces, closets, and windowsills
Examine sinks, tubs, and pipes for leaks
Step 2 – Reduce the moisture with these ten tips
When you see condensation or pooling water, dry it promptly
Use kitchen and bathroom fans to exhaust steam
Caulk and weather-strip to keep out humid air
Seal around tubs and sinks to prevent water from leaking into walls
Use an ENERGY STAR® certified dehumidifier in laundry rooms and basements
Seal off crawl spaces and cover dirt floors with polyvinyl sheeting
Install gutters and adjust downspouts to divert roof runoff
Install storm windows and storm doors in winter
Add insulation to reduce heat transfer (which causes condensation)
Improve grading around your foundation to divert groundwater
Step 3 – Improve ventilation
Ventilation removes stale, indoor air and replaces it with fresh, outdoor air. During warm months, you can open windows and doors—but the most effective ventilation comes from well-sized and properly installed fans. Besides removing moisture, clean bathroom fans and dryer vents are a must for occupant safety. Other fan options include kitchen range hoods, attic vents, and whole-house fans. For a complete assessment, hire a qualified contractor to look at your building’s ventilation, insulation, and air-sealing needs.