Whether you’ve had a washing machine leak, a leaky water supply line, or an AC unit leak into the ceiling, water damage to drywall is bad news.
Drywall is made of white gypsum mineral rock sandwiched between thick exterior paper. While it’s a great construction material due to its ease of use and versatility to create walls and ceilings, it is also a material that readily absorbs water, making it a health risk under certain conditions. Drywall is used for interior walls and therefore is it often the first thing to become damaged during a water leaking incident.
Drywall is an extremely absorbent material. The gypsum interior soaks up water like a sponge and the paper outside helps it to retain that moisture. Even on drywall that has been lightly affected by water, you’ll notice ugly water stains that must be repaired and painted. This is particularly true of the drywall ceiling.
The moisture inside drywall can infest wall cavities with mold growth. If wetted drywall is not addressed right away drywall’s main weakness will be exposed. Wet drywall will lose structural integrity. This can lead to walls and ceilings collapsing.
Do you always have to replace drywall once it gets wet? That depends on the amount of water involved. If it is only a small amount and you can get the wall completely dry (as in a moisture meter deems it safe) then it is possible to salvage drywall with a coat of spackle and paint. However, if there is more water involved and the drywall is deformed or severely stained you may never be able to get the moisture out. In that case, water damage restoration must be done to eliminate mold spores that take hold in water-damaged drywall.