How to Dry Wall Cavities and Cabinets Damaged by Water

After major water damage situations, such as those that result from storms, flooding, or burst pipes in a home, it may be necessary to dry wall cavities and other small spaces as part of the total restoration effort. When placing air movers and dehumidifiers close to the wall surface is proving ineffective, restoration professionals must drill holes into the surface to help speed evaporation.

Trapped moisture within a wall cavity can lead to the growth of mold, mildew, and bacteria, not to mention compromise structural integrity. This is known as secondary damage. Microbial growth will occur on the paper surface of gypsum wallboard if allowed to remain wet for extended periods of time. In most cases, this form of damage requires the removal of the affected material.

Wall Cavities

Wet walls can present a challenge to water damage restoration professionals. Walls are usually covered with a variety of finished surfaces, making choosing the appropriate drying technique difficult.

For walls with a single layer of wallboard and flat paint, the only drying tool needed is an air mover blowing warm, dry air along the wall surface.

For walls that are covered with vinyl wallpaper, high-gloss enamel paint, or walls with multiple layers of wallboard, it is necessary to drill holes into the wall to allow air to flow into the cavity (the space between the wall studs). Airflow in the cavity will increase the rate of evaporation, which speeds drying. You can enhance drying and evaporation efforts further by feeding air movers blowing into the wall with a dehumidifier, or warming wall surfaces with direct heat.

In order to reduce the need for extensive repairs, it is usually best to remove the baseboards and drill into the wall at the floor level. Before removing the base, use a pencil to score a light line at the top of the base. Remove the baseboard and drill holes beneath the faint pencil line. Repairs will be easier, and after the base is replaced or reset, the holes will usually be covered by the baseboards.

When drywall is installed over concrete block, it is generally dry-able if there is no insulation in the airspace between the gypsum and the block.

For walls with extensive moisture damage, it may be necessary to completely remove all wet wallboard and all wet insulation. Be sure to evaluate the needs of the situation carefully before going this route, as it is the most destructive and expensive to repair.

Typically, gypsum wallboard that has not sustained primary damage will restore quite well. All of the gypsum's strength is restored through the drying process, and sometimes even enhanced. Minimal swelling can sometimes occur, causing tape joints and fastener heads to become visible. If this should happen, and repairs cannot be made, the wallboard must be replaced.

Cabinets / Vanities

When drying cabinets and vanities, it is essential that restoration professionals take extra care to minimize damage while still thoroughly drying the structure. Unlike drywall, which can be easily patched and painted, holes drilled into cabinets cause permanent damage that ruins the entire cabinet (and greatly upsets the homeowner). 

The best place to drill holes for drying cabinets and vanities is through the toe-kick, the cosmetic cover on the very bottom portion of the cabinet. The toe-kick is usually removable and/or replaceable.

If there is no access to the toe-kick, holes can be drilled through the shelving in the bottom of the cabinets, through the wall immediately behind the cabinets, or through the back wall of the cabinet itself. These holes are either located out of sight or can be easily repaired.

When drilling holes for your wall drying system, always use an adjustable drill stop to minimize penetrating plumbing or electrical lines hidden behind the wall.

General Advice

Be sure to follow the EPA's Lead RRP procedures when drilling into drywall in buildings built before 1978. Older buildings may have lead paint, and it is essential for the protection of you, your crew, and building occupants that safe lead abatement procedures are followed.

Need technical help for a big job or assistance choosing the right products?  Call a Jon-Don restoration expert at 1-800-400-9473!