Structural and insulated sheathing? OH-BOY!

Dow has come out with another innovative product that Joe lstiburek is endorsing as well! Styrofoam SIS provides structural shear bracing and the thermal break between the studs and exterior cladding. The product is also said to be water-resistant and come in various sizes and dimensions of R-3 to R-5. This could be a great costs savings to contractors that use rigid foam on the exterior of their homes to eliminate thermal bridging and have to sheath the walls with plywood or OSB for structural sheathing as well. The product is also has a thin Thermo-Ply-Type material made up of recycled cardboard accounting for 80% of post-consumer waste which is important for the Green builders. Dow is also recommending that this product can be used as the drainage plane-however from experience I would say to wrap the home with Tyvek instead unless you want to tape every seam. Dow does recommend taping with Weather mate construction tape-and even Joe Lstiburek is impressed with the tape's performance! go to www.styrofoam.com for more information on the product, this might be a great new product for the high performance home builder. Joe does recommend allowing drying potential behind the sheathing, more information on this can be found at www.eeba.org or www.buildingscience.com