Permeability isn’t something you sit around chatting about at cocktail parties or backyard barbeques. If you are installing Tyvek in Lehi, however, knowing about permeability is a good thing. Unfortunately, most people probably have no idea what that means, particularly in regard to house building. Permeability means how well something passes through something else: water through a sheet, pulp through a sieve, and vapor through a house wrap. Knowing how well one substance passes through another and whether that is good or bad is crucial to picking the right house wrap to protect your home.

Tyvek In Lehi

Installing Tyvek in Lehi means knowing whether what you are installing will hold up. Permeability helps you figure that out, and a high perm or low perm rating is what gives you that answer. You can put a lot of weather barriers on the exterior of your home—over the frame but under the brick or siding. Felt paper is common, but we recommend Tyvek. Why? Because you want water that comes pounding on your home, driven by high wind perhaps, to stay out of your home. But you want vapor from boiling soup or taking a hot shower to leave your home so you don’t get mold. The perm rating tells you how much of this your house wrap can handle.

What permeability means is that water vapor can pass through the house wrap. We recommend Tyvek in Lehi because it has a high perm rating: rain and water from the weather can’t penetrate the weather barrier, but vapor can leave quickly—like spectators after a sporting event. Weather barriers that have a low perm rating restrict the vapor from leaving, somewhat like having only one exit after a football game. You don’t want the water vapor hanging around inside your shower to cause mold, so you want the multiple exits—and Tyvek with a high perm rating encourages that vapor to leave.

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