Do You Really Need Moisture-Resistant Drywall in a Bathroom?

Panel Features

• Moisture-resistant drywall is denser than regular drywall, and you may find that you need to cut it with a fine-tooth saw instead of a utility knife. The paper facing on the front side of the panel is thicker than standard drywall paper facing and infused with materials that repel moisture. In addition to offering protection from moisture, this type of drywall may be used as a backer for the installation of some types of ceramic tile.

Benefits and Uses

• In bathroom areas subject to heavy humidity or occasional water spray, moisture-resistant drywall is essential. Over the shower and tub and behind the sink are standard spots for installing moisture-resistant drywall. Since it’s more expensive than regular drywall, some homeowners request MR drywall only in these specific areas. If the bathroom is not properly ventilated with an exhaust fan or a window that opens to the outdoors, consider installing moisture-resistant drywall throughout the entire room.

Basement Bathrooms

• Below-grade bathrooms are subject to higher levels of humidity, often due to the reduced air circulation in basements. In addition, during periods of high rainfall, if the surrounding soil is saturated, basements may experience water leaks. Basement bathrooms can benefit from the installation of moisture-resistant drywall through the entire bathroom.

Considerations

• Do not install a moisture-resistant panel over a separate vapor barrier, such as polyethylene film, which can trap moisture in the panel, causing the gypsum particle interior to degrade gradually. Moisture-resistant drywall may not reduce the risk of mold, but mold-resistant drywall usually repels moisture in addition to discouraging mold growth. If you’re replacing drywall in a bathroom with a previous mold problem, opt for mold-resistant panels.