Keeping water out of buildings has become almost as much of a production as getting water in.
Whether in bucket, cup, or thimble proportions—above ground or below—moisture intrusion via leaks, air, and vapor is the target of new products from manufacturers. Keeping water isn’t the only problem, there’s also the challenge of keeping a building dry when moisture inevitably does find a way in.
“Moisture intrusion is the No. 1 cause of building failure in the country, dwarfing fire, earthquakes, and termites,” says Peter L. Pfeiffer, an architect with a building-science background and experience as a contractor.
A number of new flashings, membranes, wraps, tapes, and sealers came to the market in the past year to answer the call for barriers that keep moisture out effectively, release it when it does get in, and install easily.
Self-adhesion is the common theme among new membranes and wraps, with several manufacturers updating their time-tested mechanically fastened products. Fasteners, used successfully in the field for decades, allow room for leaks of air and water if they become loose. The new products attempt to solve that problem while being easier to install.
Cosella-Dörken introduced the Delta-Vent SA membrane, an air- and water-resistant barrier. The membrane adheres to most common substrates, including plywood, OSB, poured concrete, concrete masonry units, and exterior-grade drywall. Delta-Vent SA sticks to the substrate, has a moisture-vapor permeability of 50 perms, and is waterproof, says Peter Barrett, product manager for Cosella-Dörken. “This high permeability allows for rapid draining and drying of the wall system, dramatically reducing the opportunity for mold to grow and rot to form.” Delta-Vent SA is also the only vapor-permeable self-adhering air- and water-resistant barrier listed with the Air Barrier Association of America.
W.R. Grace’s Perm-A-Barrier VPS is a self-adhering, vapor-permeable air barrier membrane consisting of a breathable carrier film with adhesive that resists hydrostatic water pressure and wind-driven rain. Its light weight allows for easy handling and installation, and its flexibility accommodates minor settlement and shrinkage movement while bridging cracks and joints in the substrate. Perm-A-Barrier VPS passes the National Fire Protection Association’s 285 standard fire test as part of wall assemblies containing foam plastic insulation.
The design allows moisture to escape a building if it does get in, according to product manager Jane Wu, who notes, “You just peel and stick [the product] on the wall.”
Pactiv’s building products division recently introduced Raindrop 3D, a moisture barrier and a qualified air barrier. The product not only provides drainage, but also lets air escape the building. And Raindrop 3D allows for air movement between siding and wrap so the wall can dry.
Pactive commercial sales manager Craig Lynch says the non-perforated barrier answers builders’ search for economically priced moisture management products for cladding systems. Raindrop 3D, he says, “incorporates many properties that meet many commercial-grade air- and moisture-resistance specifications at a residential price level.”
Benjamin Obdyke introduced HydroGap Drainable Housewrap about a year ago with another selling feature besides self-adhesion. Its 1-millimeter spacers not only allow at least 100 times more bulk water drainage from a wall compared to other housewraps, the company says, but also provide a drainage space between the sheathing and cladding materials. Its low-profile drainage space eliminates the need for design changes in the wall assembly.
Three Flashes and Batten
Benjamin Obdyke also jumped on the self-adhesion bandwagon with its recently introduced HydroFlash. The product can be installed when it’s as cold as 0 degrees and can be applied on wet surfaces. Made of a block copolymer, the product features a split-release liner that self-seals around nails and delivers stronger adhesion and better cold-weather application to substrates than self-adhered flashings made of butyl or asphalt.
HydroFlash is available in widths of 4, 6, and 9 inches with a 7-millimeter thickness, it is compatible with a wide range of building materials, including OSB, CDX plywood sheathing, and vinyl.
DuPont recently launched two new products for moisture management and energy efficiency: Tyvek brand Fluid Applied flashing and the RainVent Batten. The flashing is a brush-applied, vapor-permeable elastomeric material used to protect rough openings of recessed residential windows, particularly those with irregular corners. The batten provides a ventilated rain screen and drainage plane for use with weather barriers to improve drying of undrained moisture behind cladding materials.
Huber Engineered Woods released Liquid Flash, used as part of its Zip System sheathing to create a continuous barrier against air and water infiltration. Seamless, it provides instant rough dry-in during construction and is designed for sealing irregular, curved, or hard-to-flash door and window openings in residential and commercial construction.
Liquid Flash is easy to gun, spread and tool in harsh weather conditions and bonds to damp and dry surfaces without a primer, the company says.
“The recent trend of tightening buildings has made it very important to make sure that the sealant will last the life of the building and aggressively bond to the bonding surfaces,” says Clarke Berdan II, senior technical service leader for installation at Owens Corning. “The key is to create a very positive seal when you’re covering a gap or flashing around an opening.”
Owens Corning JointSealR Foam Joint Tape is used to tape the joints of extruded polystyrene insulation board, providing adhesion, strength, and flexibility. It adjust to building materials as they flex, avoiding gaps in the weather barrier.
Protecto Wrap introduced Protecto Form Flash 1, a peel-and-stick flexible flashing tape used as a primary air and moisture seal around wall openings and penetrations in residential and commercial construction. As a permanent barrier to air and vapor, it increases the energy efficiency.