Tyvek and tar paper are two materials commonly used as weather-resistant barriers in building construction, but they have different characteristics, applications, and benefits. Here’s a detailed look at the differences between them:

Tyvek (Housewrap)

Material: Tyvek is a brand name for a synthetic material made from flash-spun, high-density polyethylene fibers. It is a product of DuPont and represents a range of housewrap products designed to be used as building wraps.

Properties:

• Breathability: Tyvek is highly breathable, allowing moisture vapor to pass through it, which helps prevent mold and water damage inside the walls.

• Water Resistance: It effectively resists water penetration, keeping rain and other external water sources out while allowing water vapor from inside the home to escape.

• Durability: Tyvek is very durable and resistant to tearing. It can withstand exposure to UV light and harsh weather conditions during construction.

• Installation: Tyvek is lightweight and comes in large rolls that are easy to install. It is typically fastened with staples and taped at the seams to provide a continuous barrier.

Uses: Tyvek is used in a wide range of construction projects, particularly in residential buildings for walls, and can also be used in roofs and flooring applications to improve energy efficiency and comfort.

Tar Paper (Felt Paper)

Material: Tar paper, or roofing felt, is made from fiberglass or polyester fleece that is impregnated with bituminous materials (asphalt or tar), which makes it waterproof.

Properties:

• Breathability: Tar paper is less breathable than Tyvek and other housewraps. While it does allow some moisture vapor to escape, it is not as permeable, which can sometimes lead to moisture issues if not used appropriately.

• Water Resistance: It provides excellent water resistance and has been a traditional choice for roofing underlayment due to its ability to repel water.

• Durability: While tar paper is durable against water, it can degrade under prolonged exposure to sunlight and can tear more easily during installation than synthetic wraps.

• Installation: It is heavier than Tyvek and can be more cumbersome to handle and install. It requires nails or staples for installation and is usually covered quickly to avoid degradation from UV exposure.

Uses: Traditionally used under shingles on roofs to prevent water penetration, tar paper is also used in some siding applications, especially where budget constraints are significant.

Summary of Differences

• Material Composition: Tyvek is a synthetic, while tar paper is an organic material saturated with asphalt.

• Breathability: Tyvek offers superior breathability.

• Durability Against UV: Tyvek is more UV-resistant.

• Weight and Ease of Installation: Tyvek is lighter and generally easier to install with less risk of tearing.

• Application Specificity: Tyvek is more versatile with broader applications in modern building practices, while tar paper is traditionally used and still preferred by some for roofing due to its cost-effectiveness and water-repelling properties.

Choosing between Tyvek and tar paper will depend on the specific requirements of your construction project, including climate considerations, the building’s design, and budget constraints.