The current shortage of skilled labor is one factor encouraging builders to use products that make tighter, more energy-efficient building enclosures in less time, says Prosales contributor Scott Gibson.
Gibson presents some new offerings in the sheathing and housewrap category that get the job done:
Sheathing That Does More
Huber Engineered Woods has had a runaway bestseller with its Zip System sheathing for both walls and roof. It combines structural sheathing and a coating that eliminates the need for a separate weather-resistive barrier (WRB). When used in conjunction with a proprietary sealing tape, the sheathing is an effective air and moisture barrier. Huber dominates this part of the sheathing market, but it’s no longer alone. Georgia-Pacific introduced a product called Force Field. There also are entries in the coated sheathing category from Ox Engineered Products (Thermo-Ply) and RoyOMartin (Eclipse, a radiant barrier). Huber now offers a version of its Zip sheathing that comes with a layer of polyisocyanurate insulation to reduce thermal bridging. Zip System R-sheathing, which comes in four thicknesses and with R-values of up to R-12, is the fastest-growing product in its portfolio.
More Options for WRBs
GreenGuard RainDrop 3D housewrapManufacturers continue to broaden offerings for weather-resistive barriers that are applied beneath the cladding, a category that DuPont started with the commercialization of Tyvek 50 years ago. There are now at least nine manufacturers, including James Hardie, Fiberweb, CertainTeed, Owens Corning and Dow. Newer entries include RainDrop 3D in Kingspan’s GreenGuard product line. RainDrop has a textured surface that enables any water getting past the cladding or flashing to drain away, even when siding has been nailed tightly against it, according to the manufacturer. The product would appear to be aimed at builders who now apply cladding over a vented rain screen , as it combines two steps (applying a WRB and then furring strips) into one.
New on the Insulation Front
Recent developments in the thermal insulation category are more about incremental changes rather than revolutionary steps, but green-building advocates have to be pleased with announcements from both Rockwool (formerly Roxul) and Owens Corning that binders containing formaldehyde are being phased out in some of their products. ThermafiberRockwool said last spring that the changes would initially affect its light density AFB batt insulation, in part to allay concerns among builders and designers that formaldehyde off-gassing from mineral wool insulation posed health risks. Owens Corning said the no-added formaldehyde binders would be used in its Thermafiber insulation. Firestone photoPolyiso board insulation from FirestoneFirestone Building Products is set to launch a reformulated polyisocyanurate board insulation that improves low-temperature performance. Insulation Product Manager Edward Klonowski says its rebranded Isogard and Envergeboards test at R-6.3 per inch at 40 degrees while the R-value per inch in earlier versions dropped to R-5 per inch at that temperature. They still use Pentane as a blowing agent, Klonowski says, but tweaks in other chemical components made the upgrade possible. CertainTeed has introduced two new types of fiberglass batt insulation: EasyTouch, which comes with a perforated plastic film coating to reduce dust and make installation less itchy; and SmartBatt, which incorporates a smart vapor barrier to limit vapor transmission into wall cavities when humidity in the walls is low.
Changes in Framing Products
Basic framing doesn’t change quickly—witness the painfully slow adoption of Optimum Value Engineering—but manufacturers have updated several products that either improve durability or save builders time. Weyerhaeuser has introduced a new coating for its Trus Joist Eastern Parallam PSLbeams and columns that reduces moisture absorption while the material is stored in the yard and during construction. Eastern Parallam PSLs are available east of the Mississippi and are made for interior use. Boise CascadeBoise Cascade's AJS 24 FM I-joistBoise Cascade says it has increased production of its AJS 24 FMJ I-joists, designed for use in unfinished basements. The I-joists have a foil coating to meet the ASTM fire test, and have no specific top and bottom orientation to make installation a little easier. Louisiana Pacific hopes rising framing lumber prices will convince more builders to use its LSLs in selected areas of the house—on kitchen walls, for example—where straight and plumb are worth a few extra bucks. Reid Williams, an application engineer at LP, says the company’s biggest challenge is to convince builders to use a value-added product. But when LP gets a chance to engineer a job and save the builder money, he adds, “it’s usually a slam dunk.”
