It’s easy for small amounts of water to enter a home’s wall cavity, both during and after construction. When water evaporates it becomes a gas (water vapor) that needs to escape. If the walls can’t completely dry, a home is more likely to experience mold and rot.
A building material’s ability to let water vapor pass through is called permeance, measured in units called “perms.” There are two ways that the American Society of Testing and Materials (ASTM) measures permeance in its E96 test: Procedure A (desiccant or “dry cup” method) and Procedure B (water cup or “wet cup” method).
Here are some common misconceptions about building enclosure performance and the truths behind them:
TRUTH: “Whether a vapor-control material is 5 perms or 35 perms, the drying rate is usually limited by other materials like the cladding,” says John Straube, a principal at RDH Building Science and an associate professor at the School of Architecture at the University of Waterloo in Canada.
TRUTH: “The house wrap industry emphasizes the ASTM E96 Procedure A or ‘dry cup’ test,” adds Straube. “But the test that’s more appropriate for in-service use of wood-framed buildings is really Procedure B or the ‘wet cup’ test. I have a colleague who says, ‘Procedure A measures how much water vapor passes through when there isn’t any water vapor, while Procedure B measures how much passes through when there is water vapor.’”
TRUTH: It defeats the purpose of an air/water barrier if a home’s exterior flashing isn’t done properly. “There are far greater mold risks when sheathing gets wet after the home is occupied than when it’s being built,” says Straube. “If windows leak into the wall, that’s really scary because you can’t see it.”
Learn more about the LP WeatherLogic™Air & Water Barrier system, the latest addition to LP’s portfolio of structural solutions.
January and February typically usher in the season’s coldest temperatures, bringing the need to use building materials that can withstand frigid temperatures with them. However, it’s often the freeze/thaw cycle––cold days followed by quick warm-ups––that can cause significant damage to a home’s siding. So, what is the best siding for cold climates to combat this?Continue Reading
With temperatures dropping, insulation and protecting new construction against the elements are top of mind. Of course, builders must consider how insulated wall sheathing can help meet code requirements and contribute to the overall performance of the building envelope. However, they must also carefully consider potential moisture problems both during and after the build and the potential impacts of freeze/thaw cycles. With the season of potential hard freezes followed by fast warm-ups upon us, let’s explore methods for choosing the best house sheathing for cold climates.
With housing demand at an all-time high, builders do not have the ability to halt home construction during the winter months. Builders can work safely year round, even building houses during winter with planning and preparation. Advanced products and installation methods allow work to be performed during wet and very cold temperatures, but builders also need to consider winter safety for construction workers.
Engineered wood siding has long been considered a trustworthy exterior product for single-family homes, but it is often overlooked for multifamily and commercial construction. LP® SmartSide® products are versatile enough for a range of builds beyond traditional single-family homes. Take a look at the homes featured in Madison Parade of Homes for siding inspiration and to see how LP SmartSide Trim & Siding might suit your building needs.