Moisture damage is a problem in many homes, both old and new. The technology and products being used just a decade ago are not doing the job.

“Today, building science experts have found that some building products and faulty installation methods used just a short time ago have contributed to the structural damage that homes are currently experiencing today.” says Lee Haller, owner of Haller Custom Homes, a builder of high-end homes and residential neighborhoods in the western Philadelphia suburbs. Haller’s company specializes in remediation and restoration of moisture-damaged homes.

Haller says the construction industry has taken great strides to create new approaches to avoid bulk water intrusion, and to drain and dry any water that does manage to penetrate the exterior cladding. But what to do with newer homes that were built before these best practices were introduced?

According to housingzone.com, one solution to avoiding the problem of bulk water intrusion has been the incorporation of a rainscreen system in the home’s design. A rainscreen, as described by the National Association of Home Builders (NAHB)

Research Center, is a moisture-management system incorporating cladding, an air cavity and a drainage plane to shed moisture and prevent moisture intrusion and the resulting premature decay in homes.

Haller adds that builders constructing homes without a rainscreen system behind any absorptive cladding like stucco, stone or fiber cement should also think twice. “I know for a fact that the builders who are dealing with liability issues for the repair of the original construction are finding that the cost of the repairs totally erase the profit they made on the home when it was first built, and then some,” he says. “I say spend the little bit extra when the home is being built and avoid the huge possible expense down the road.”

The NAHB recently issued an educational guide that discussed the need for better drainage behind so-called “absorptive” exterior claddings, which include any materials that are semi-porous and may transmit or retain some water. This can include stucco, manufactured stone, stone veneer and even fiber-cement siding. Among the products referenced that can be used as part of an effective building envelope system is a wall drainage spacer, described as an “open-weave plastic mat.”

Haller’s Approach:

•After studying the home’s condition, erect scaffolding and begin removing the stucco.

• Examine the sheathing. If the OSB or plywood is damaged, replace it. With OSB , run a circular saw around the joints of the OSB to create a 1/16-inch gap.

• Replace damaged 2 x 4s or other structural framing.

• If windows are damaged or other specific conditions are present, re-install them or replace them using the latest wrap products and flashing for moisture-resistance. Cover the windows for protection.

• Remove the cornice and apply the water-resistant barrier to the entire wall, including behind where the cornice had been. Gables are extended to create an overhang to prevent water entry.

• Install Benjamin Obdyke’s Home Slicker Stone & Stucco.

• House is watertight at that point and ready to stucco.

Alternatives to Home Slicker include offerings from:

Sto Corp.

Vaproshield

Dow

Masonry Innovations