Finishing An Unvented Attic

Control of ice dams moisture accumulation and heat gain can be successfully addressed by both vented and unvented attic or roof design.

Finishing an unvented attic.

During the spring summer and fall relative humidity rh in a spray. An unvented attic is one which is not ventilated and this is important one where the ceiling has complete air vapor and thermal controls in place. The irc has permitted unvented conditioned attics since 2006 with certain requirements. I have a shop in my attic for some of my hobbies and it get s very hot in the summer.

Closed cell is a vapor retarder meaning water from a leak could be trapped against the roof sheathing. But in many spray foamed attics it can be hard to manage humidity. The choice of the venting approach is up to the designer. The energy savings touted by unvented attics can be as high as 20.

Unventilated attics can help to mitigate energy loss through leaky ducts or ceiling fittings. Adding unvented attic insulation like spray foam seals the building envelope and stops airflow. A fundamental requirement of an unvented attic assembly is the use of air impermeable insulation on the underside of the unvented roof to prevent air infiltration and exclude airborne moisture from the attic. The roof deck in an unvented attic must be exceptionally airtight.

Both vented and unvented attic roof designs can be used in all hygro thermal regions. The unvented attic system or conditioned attic is the new way to make your attic energy efficient. Unvented attic system pros and cons. To provide an unvented conditioned space for locating hvac equipment in the attic and or to provide a continuous thermal barrier for designs that have complex coffered ceiling planes and or numerous penetrations for lights speakers vents.

Once an unvented roof is finished it s awfully damn difficult to notice roof leaks. If you want you can even transform a spray foamed attic into a finished space. The acceptance of unvented conditioned attics continues to grow among builders and building officials. However the designs need to be climate sensitive.

Install insulation along the underside of the roof deck of an unvented attic rather than on the ceiling deck of a vented attic for either of two reasons. Code requirements vary across the country. The attic space becomes indirectly conditioned as a result of the air leakage heat transfer and vapor diffusion through the ceiling. This air seal will help to make your home more energy efficient.

Can i put a small swamp cooler or ventless a c unit up there to cool it only to use while i am in my shop maybe an hour or two a couple times a week.