Drywall, also known as plasterboard or gypsum board, is a material made from gypsum covered with a fibreglass or paper covering. It is used in construction to create walls over and between pieces of framing lumber. Drywall replaced plaster walls which were expensive to construct and expensive to repair. Certain conditions can create problems with drywall and may be the cause of crumbling drywall panels in your home.
In climates with constant humidity, a large amount of moisture may permeate the air in the home. Even with air-conditioning, this constant moisture can seep through paint coatings and into drywall, causing the material to absorb water and eventually begin to crumble. This condition makes hanging pictures, shelving and other items on the wall difficult because there is no solid structure within the walls to hold the nails.
Homes that have undergone flooding often remain wet for some time afterward. Carpets can remain damp long after the water has receded and ordinary water removal methods, like running fans, have dried some surfaces. This moisture can seep into baseboards and into drywall. As the moisture spreads through the gypsum, it deteriorates the interior composition of the drywall, which begins to crumble.
Termites are insects that feed on wood, paper, insulation and other materials and do billions of dollars of damage to homes each year. They are often confused with ants, but have straighter waists, straighter antennae and wings of uniform size. Wood damaged by termites is used eaten along the grain, with bits of dried mud or soil lining the tunnels. Termites can also tunnel tiny holes into drywall, leaving the internal material weakened and crumbling.
Repairing Crumbling Drywall
The best method of repairing crumbling drywall is to remove and replace the affected panels. It's important to correct the underlying problems that cause the crumbling. If constant humidity is weakening the material, run a dehumidifier in the affected areas. Repair leaking plumbing, water seepage in foundations or other moisture intrusions that causes the crumbling problem. Replace damp carpeting or have the area treated by a professional flood remediation company. If the crumbling area is small and appears to be limited, patch the area with a drywall repair screen and cover it with drywall patching compound, then repaint to match the wall. Engage a pest control specialist to diagnose and treat possible termite problems in your home that may be causing the drywall to crumble.