It’s important that use the building paper that is recommended for your area. Many builders use standard 15-pound roofing felt. Felt labeled “ASTM 15” meets specific standards and is the norm in many areas. Felt or building paper must be applied to walls properly to be effective. Install pieces in the correct order and make cuts carefully, so any moisture can travel downward at all points without slipping under the wrap. Install flashings (metal, self-adhesive, or both) as recommended by the window or door manufacturer or as required by local codes. Pull the wrap tight when you install it to prevent creases that could lead to slight waves in the siding. Working with one or two helpers, expect to spend half a day applying 1,600 square feet or so of building wrap. It will take more time if extensive flashings are required. Before you begin, remove any old siding, nails, and building wrap from the sheathing.
