Spray Foam Unvented Attic

The roof deck in an unvented attic must be exceptionally airtight.

Spray foam unvented attic.

The acceptance of unvented conditioned attics continues to grow among builders and building officials. When you insulate the top of your attic with spray foam you re bringing your attic into your home s envelope as a result you can reduce the temperature in your attic by a lot anywhere from 120 degrees to around 95 during peak summer. The trusses do cost more but this added expense can be mitigated by a. Code requirements vary across the country.

This construction approach was first used in the 1970s and it has been implemented much more widely since it was first included in the international code council s icc model building code in 2007 irc section 806 4. The unvented attic space is considered the most effective and up to date building practice particularly by the spray foam industry. Unvented attics sometimes called sealed enclosed or encapsulated attics feature insulation on the underside of the roof decking rather than on the attic floor. Unvented roof assemblies should be insulated either with air impermeable insulation rigid foam or spray polyurethane foam or with a combination of foam and air permeable insulation.

Common problems found with traditional insulation in an unvented attic assembly can be mitigated with spray foam insulation like icynene. An alternate to spray foam insulation in an unvented attic is plenum trusses which allow you create a reverse bulkhead above the ceiling plane that is insulated. Spray foam insulation in an unvented attic assembly has been one of the most researched and widely implemented innovations of recent years. Keep bulk moisture out closed cell spray foam is a.

The irc has permitted unvented conditioned attics since 2006 with certain requirements. This allows you to install your bulkheads above the ceiling plane without the need for spray foam insulation. Generally any attic insulation project is going to cost between 2 50 to 3 50 per square foot insulating attic roof with spray foam insulation will save money types of attic spray foam insulation open cell closed cell how to insulate an attic roof rafters when properly installed either type of spray foam insulation will act as a. If you don t want to use sips or nailbase read this article tolearn the four basic approaches to insulating unvented roof assemblies.

We mean that literally by the way. Most unvented attics incorporate spray polyurethane foam spf on the underside of the roof deck and attic walls. Attics with spray foam insulation are so cool. Over time feedback from builders and building owners has been and continues to be overwhelmingly positive especially in the areas of moisture performance energy efficiency and building durability.