When installing housewrap, you want to achieve a continuous membrane that resists air and water penetration into the structure. The correct installation of STYROFOAM™ WEATHERMATE™ Plus housewrap is a simple, fast process. DO NOT INSTALL HOUSEWRAP AND NEW SIDING OVER WALLS THAT HAVE DETERIORATED FROM MOISTURE, INSECTS, ETC. REPAIR UNSOUND WALLS PRIOR TO PROCEEDING.
1. STYROFOAM WEATHERMATE Plus housewrap does not provide a flat, level surface over old siding. Install STYROFOAM WEATHERMATE Plus housewrap over leveling board or insulating board that has been installed over old siding. OR, remove the old siding and install STYROFOAM WEATHERMATE Plus over the old sheathing.
2. Install STYROFOAM WEATHERMATE Plus housewrap over the entire wall surface, including windows and doors. Start at the bottom of the wall and work up. Fasten 1/2" into wood nail base with 1" head plastic cap nails or 1" head staples spaces 12"-16" in each direction.
3. Overlap vertical and horizontal joints 6". Be sure upper layers of housewrap lap over lower layers shingle fashion so water will be shed.
4. Cut housewrap around edges of windows and doors. Tape and seal the housewrap to the existing window and edges and to resist water and air penetration.
5. Old flashings may have to be extended and integrated with new housewrap and sidings.
6. Before installing exterior finish, be sure all penetrations are taped to shed water and prevent air infiltration.
7. Install new siding (and new windows if applicable) according to manufacturers instructions.
8. Although Dow does not require an air space between STYROFOAM WEATHERMATE Plus housewrap and exterior finishes, good building practices and some building codes specify air spaces behind brick, stone and wood finishes.
9. STYROFOAM WEATHERMATE Plus housewrap should not be exposed to sunlight for more than 120 days in the United States.
Note: STYROFOAM WEATHERMATE Plus housewrap is a secondary defense against bulk water intrusion. The exterior finish is the primary water barrier. Wall assemblies are best protected from water intrusion by installing the exterior veneer over water repellent sheathing or installing the exterior veneer over a weather-resistive membrane which is installed over exterior sheathing. If STYROFOAM WEATHERMATE Plus is installed directly over studs with no sheathing, the exterior veneer must be carefully chosen and installed to provide maximum protection against water intrusion.