Tuesday, January 8th, 2019 by Ruthy Singletary
If you have bought an older home, chances are there isn't any house wrap underneath the siding. House wrap, otherwise known as a Weather Resistant Barrier (WRBs), is hung on the outside walls of the house before the finishing exterior portion is put on, whether that be siding, brick, stucco, ect. WRBs serve 3 purposes. It prevents moisture, inhibits mold, and helps prevent drafts. It has recently become code to put WRBs on any new construction building. Think about back in the old days in 1920 when insulation and housewrap didn't even exist. Talk about some drafty cold houses.
When used to slow winds, its job is to seal gaps and leaks in the OSB panels or plywood sheathing that makes up your home’s exterior walls. That keeps drafts from reaching your insulation and prevents heated and cooled air from seeping out through the walls. Although your siding is your home’s first defense against wind, many types have small gaps and cracks at the joints where siding panels line up. And that leads to air infiltration and seepage—the kinds of things that drive up energy costs.
Moisture barrier housewraps do the same thing, but for rain, snow, and other outside moisture. They’re usually made with a permeable material that allows water vapor to travel through them—but keeps out water droplets. This helps them dry out quickly, and prevents problems from mold that can happen when water sits on the surface