Discovered in 1955 by a DuPont scientist, Tyvek is made of high-density polyethylene fibers. This thin plastic is used for everything from car covers to envelopes to wraps used to envelope houses, where it protects against wind and rain. Tyvek is "breathable," meaning that it allows moisture vapor to pass through rather than being trapped within walls. Water itself rolls off Tyvek and cannot penetrate it. Tyvek can reduce energy bills, keeping houses warmer in the winter and cooler in the summer.
Tyvek in Ceilings
Builders generally use Tyvek on the outside of a structure to protect from moisture and serve as an insulating layer, but the material can serve these functions on the interior as well, primarily in basements and attics. Owners of drafty log cabins have installed Tyvek in their ceilings to increase warmth, while some business owners have used it as an innovative way to protect their merchandise. Czarnowski Display Service in Chicago, which manufactures exhibits and displays, constructed a drop ceiling made of wood frames and Tyvek, which allows light to filter through but repels dust.
Tyvek can help keep a basement's cooler air from traveling to warmer upper floors. Some homeowners have used Tyvek to bolster insulation in the ceiling by stapling it to the bottom of joists. The Tyvek can then be covered with a traditional ceiling finish or left uncovered in unfinished basements.
DuPont manufactures Tyvek AtticWrap, which is used under shingles and plywood but over the attic rafters and trusses to increase a house's energy efficiency and moisture control in the attic. In unfinished attics, the Tyvek serves as the ceiling material. It allows moisture in the attic to vent in cold weather and helps keep heat from building up in the summer. When Tyvek is installed so it faces downward into the attic, it can help reflect heat toward lower floors in cold weather.