Insulation professionals can apply spray polyurethane foam (SPF) insulation directly to the roof deck and other attic areas creating an unvented attic (UVA). The use of SPF insulation can also help tie together the attic and wall insulation, creating a continuous insulation system in the building envelope.
SPF Advantages for Unvented Attics
SPF is an ideal choice for UVAs because it acts as an insulation and air sealant. SPF expands on application, filling gaps and sealing air leaks in the attic walls and roof.
This helps prevent air infiltration and can reduce air-conditioning loads providing further reductions in energy consumption.
Unvented Attics with SPF Help Save Energy and More
UVAs with SPF helps compensates for leaky ductwork in the attic space. Duct air leakage commonly exceeds 20 percent of conditioned air flow, which results in a significant energy loss when ducts are in unconditioned space. It also reduces the loss of conditioned air through the attic (stack effect). Like a hat on a cold winter day, UVAs help reduce energy loss through a home’s attic. An UVA can keep a home warmer in winter and cooler in summer, reducing the HVAC load.1 UVAs in most cold climates decrease the heating load by about 10 percent.2
A Great Choice for New and Existing Construction
Both new and existing construction can be designed for UVAs, meaning all homeowners have the opportunity to benefit from energy savings. In a new building, the UVA can be installed during the construction process with SPF applied directly on the underside of the attic walls and roof, leading to maximum coverage and air sealing. In an existing building, the spray application for SPF allows the product to be applied around any existing obstacles and into the hard-to-reach spaces of an attic.
Choose a Trained Contractor
To ensure that SPF is properly installed, it is important to choose a properly trained installer. A trained SPF contractor can answer your questions on product selection and application process. When considering a UVA in an existing home, it is important to coordinate with other experts, such as the HVAC contractor, to ensure the entire system works together to create a more efficient building envelope.3 Always follow the state and local building code requirements.
Additional Spray Foam Resources
Guidance on Modeling Unvented Attics in CA
See how SPF can be useful for the California Energy Commission’s 2016 requirements for High Performance Attics.
Guidance on Removal & Disposal of High Pressure SPF
Learn more about the variety of factors to consider when removing high-pressure SPF insulation from buildings.