Foam Insulation Roof Rafters

Often the r value of fiberglass insulation is too low and requires the rafters to be retrofitted making foam board a better choice.

Foam insulation roof rafters. Use closed cell foam it green for attic rafters. Encapsulating the rafter or top truss chord roof framing members with spray foam will improve the energy efficiency of the attic space. It typically has 3 variations. Polyurethane or polystyrene spray foams can provide thorough coverage to roof rafters and attic walls in much less time than is needed for other materials.

The airflow from the soffits to the ridge vent keeps the roof cool and prevents ice dams and the material will block that flow. This is because the effects of thermal bridging are limited which also results in the elimination of melt lines on the roof surface in cold climates. Step 1 prepare the roof. Place a ridge cap over the ridge to hide the gaps.

The best attic insulation. 100 free of cfcs vocs penta bdes urea formaldehyde. R value of 7 in 1 inch 97 closed cell foam. For the same reason insulation shouldn t touch the roof s underside.

Get your kits the easy to use spray foam kit. Unlike solid insulation products that require careful measurement cutting and fitting spray foam can cover even the most uneven surface instantly. I had spray foam insulation installed into a 55 year old house 5 years ago. Bare foam board one sided sheathing board or double sided which is also reference as structural insulated panels.

A vent baffle should be installed between the insulation and the roof decking to maintain the ventilation channel. If you are adding foam insulation to your roof rafters you must also properly ventilate the area. Rigid foam board is just above the roof deck or an exterior insulation option. I still notice a smell permeating the upstairs of the house on hot days which is concerning over 5 years.

I live in the northeast. The foam was applied to the attic rafters and walls. When building my current home i was faced with a dilemma on how to insulate a bonus room that would be upstairs. You can also add rigid foam insulation under the rafters which adds r value and eliminates thermal bridging through wood rafters.

Build the rafters and secure the 5 8 inch cdx sheathing material. Consider using high density r 30 batts which are as thick as r 25 batts but fit into 2x10 framing. The previous four options are all used beneath the roof. Class i e 84 fire retardant meets building code spec.