Why do manufacturers produce so many varieties of house wrap? This question is common for contractors as the only visible difference between them often is branding.
While all-weather barriers might be similar in appearance, many of these products are designed for specific construction conditions. Manufacturers have focused on problem areas for contractors and have created specifically-engineered varieties of house wrap to address these concerns. We’ll review two common building scenarios and highlight how innovation has made house wraps more effective at addressing the performance requirements associated with these applications.
One of the primary goals of weather barriers is to help facilitate the drying of wall systems. If a wall gets wet, and the water sits, severe issues like mould can occur. To fight against this problem, most house wraps are designed to be vapour permeable. This permeability allows water vapour to escape through the house wrap while simultaneously keeping water droplets out. This feature helps walls dry quickly and limits moisture-related damage.
Though this permeability is adequate to prevent water damage for most housing projects, there are scenarios where typical house wrap will not suffice. For example, homes with stucco or wood siding are particularly prone to high quantities of water intrusion. Additionally, houses built in wet climates with substantial exposure to wind-driven rain are at a heightened risk.
When building a home under these conditions, it is in the contractor’s best interest to select a weather barrier with a higher capacity for drainage. An example of a house wrap in this category would be Tyvek’s DrainWrap. DrainWrap has the same features as a typical house wrap, as well as vertical grooves integrated into its design to help channel water between the house wrap and the siding. With this unique design, it’s tailor-made for situations where moisture could be a problem, efficiently guiding water downward to protect the home.
Another factor to consider when selecting a house wrap is sun exposure. A typical house wrap has around 120 days of UV durability. This timeline means that contractors have approximately four months to side a building after installing the weather barrier. If the siding is not finished in this timeframe, the house wrap will likely be compromised and won’t perform as it should.
Although four months is an adequate amount of time for single-family dwellings, this is not the case for larger projects. For example, when contractors are working on commercial buildings, or building multiple homes simultaneously, the house wrap can often be exposed for longer than four months before the builder gets to the siding stage of the project.
For projects with longer timeframes, manufacturers have developed hardier house wraps with increased durability. These weather barriers are thicker and have additional UV stabilizers added to them during the production process. These two steps make the barrier increasingly resistant to the elements and give the contractor significantly more lead-time to install siding. For example, Tyvek’s CommercialWrap has an impressive nine months of UV resistance with remarkable tear strength. This durability means that builders do not need to rush to complete the siding stage and ensures the project is done right the first time.
When it comes to selecting house wrap, matching the correct type to the corresponding building conditions is extremely important and will contribute to a building envelope that performs as it is meant to.