Tyvek® HomeWrap provides the optimum balance of properties for superior performance against the elements and the competition. When choosing Tyvek® HomeWrap, you can be assured you are using the leading brand of wall underlays.
Features & benefits
A wall underlay is a home’s main protection against the damaging effects of the elements. The optimal wall underlay must include four key properties:
- Air resistance to help prevent the flow of air through wall cavities and reduce drafts.
- Moisture resistance to help protect the wall cavity from water that gets behind the cladding.
- Moisture vapour permeability to promote drying of wall systems.
- Durability to withstand the rigours of the construction site and to continue performing once construction is completed.
A balance of these four properties is crucial in helping to maintain the protection, comfort and efficiency of a home.
Defining the difference
Tyvek® HomeWrap® is a nonwoven, non perforated sheet made by spinning extremely fine, continuous, high-density polyethene (HDPE) fibres that are fused together to form a strong, uniform web. The fibrous structure is engineered to create millions of microscopic pores that resist bulk water and air penetration while allowing moisture vapour to pass through. Tyvek® HomeWrap® is the only product manufactured using this unique process; therefore, only Tyvek® HomeWrap® achieves the optimal balance of air resistance, water-resistance and moisture vapour permeability. Other wall underlays compromise such features as bulk water hold-out for vapour permeability, or vapour permeability for air resistance.
Air penetration resistance
One basic function of a wall underlay is to help insulation maintain its R-value by keeping air from infiltrating the wall system. The ability of a wall underlay in helping to prevent air infiltration directly relates to the energy costs of heating and cooling a home. Many wall underlays fail to meet the basic air barrier requirement of ≥0.1 MNs/m³. The high air resistance level of Tyvek® HomeWrap® allows insulation to be more effective, helping to lower energy costs.
Bulk water hold-out and vapour permeability
The building industry continues to face challenges with moisture-related issues resulting from wall systems that failed to manage the incidental moisture that enters and cannot escape a wall cavity. High bulk water resistance and high drying potential are key components of creating the optimal wall system. Tyvek® HomeWrap® has a high resistance to bulk water penetration, helping to reduce the damaging effects of moisture penetration. At the same time, the high Moisture Vapour Transmission Rate (MVTR) of Tyvek® HomeWrap® ensures that water vapour does not linger in the walls but passes to the outside where it belongs. A wall underlay should have a high perm rating so that the natural ability of a wall system to dry out is not impeded. The excellent moisture vapour permeability of Tyvek® HomeWrap® helps prevent moisture accumulation in walls which can lead to the formation of mould, mildew and wood rot.
Tyvek® HomeWrap® provides excellent tear strength and good wet strength combined with a superior UV resistance of 120 days. Conscientious builders choose Tyvek® HomeWrap® over any other product because it withstands the rigours of the construction site and offers an easy solution to protect the homes they build from the harmful effects of the elements once construction is completed.