With so many house wraps on the market today, how do contractors and building owners decide which is the best? Most house wraps are weather-resistant barriers (WRBs) that aim to prevent air and moisture infiltration to the wall system while protecting the sheathing.
In this post, we compared Barricade® Wrap Plus, Tyvek® HomeWrap®, HomeGuard® House Wrap, CertainTeed CertaWrap™, and the ZIP System®. There were several vital performance components we considered when comparing these house wraps. These elements included durability, water and air resistance, vapor permeability, and drainage.
A durable house wrap can stand up to the handling and installing process without becoming damaged, which will lessen its water-resistance performance. Durability parameters include ultraviolet (UV) rating, tensile strength, and cold and surfactant resistance.
A crucial requirement of a house wrap is to keep water out of the wall assembly. The ICC-ES allows for three water-resistance testing standards; however, plastic wraps are permitted only to use the first two.
A house wrap’s air resistance is a continuous system that stops the flow of air across the building envelope. Three tests determine the air resistance of house wraps.
Vapor permeability (measured in US perms) is the amount of vapor transmission that a house wrap permits over a time period. The ASTM E96 (Test Method for Water Vapor Transmission of Materials) measures perms. A high perm means the wrap has high vapor permeability. But, it can’t be so high that the moisture can penetrate from the outside into the wall system.
According to Joseph Lstiburek, with the Building Science Corporation, the ideal WRB perm, for balancing the inward and outward flow of moisture in a wall system, is between 10 and 20 perms.
Drainage is an effective method to lessen moisture infiltration to the wall assembly due to rain. A house wrap’s design should provide an integrated gap and a drainage plane so to resist bulk water.
Barricade® Wrap Plus is a non-perforated, non-woven polyolefin product with a semi-permeable membrane. Barricade® Wrap Plus’ breathable and micro-porous membrane controls air and moisture infiltration, yet its permeability allows evaporation of moisture vapor if it makes its way inside the wall assembly. Barricade® Wrap Plus resists rain (bulk water penetration).
Tyvek® HomeWrap®, a product of DuPont™, is made from non-perforated, non-woven, high-density polyethylene fibers that are fused to create a uniform web. The web creates tiny pores that resist water and air penetration while permitting vapor to pass through.
Benefits of Tyvek® HomeWrap®
Disadvantages of Tyvek® HomeWrap®
HomeGuard® House Wrap is an engineered, woven, polyolefin product designed for use as a secondary WRB.
Benefits of HomeGuard® House Wrap
Disadvantages of HomeGuard® House Wrap
CertaWrap™ Standard house wrap is a coated poly woven fabric weather-resistant barrier, manufactured by CertainTeed.
Benefits of CertaWrap™
Disadvantages of CertaWrap™
The ZIP System®, manufactured by Huber Engineered Woods, LLC includes ZIP System® sheathing panels and self-adhesive tape. The panels comprise oriented strand board (OSB) wood structural sheathing with a Grade-D 60-minute WRB exterior facer of medium density phenolic-impregnated polymer-modified product. The seam sealing tape is a polyolefin sheet, backed with acrylic adhesive.
Benefits of ZIP System®
Disadvantages of ZIP System®
A high-performing house wrap has the right balance of air and water resistance and vapor permeability to prevent air and moisture infiltration. It must also have the strength to withstand damage during and after construction.