How To Insulate 2x6 Roof Rafters

So your choices are 3 1 2 thick batt insulation for an r value of about r 11 9 or rigid insulation board for a r 20 to r 30 depending on the type of board.

How to insulate 2x6 roof rafters.

It creates a breeding ground for mold and mildew and ruins the air trapping pockets that block heat flow. For example if the space beneath the rafters is going to be used for a living area then you will need to insulate the roof rafters. Water is insulation s enemy. If you choose to use the 2x6 roof joists you ll only be able to fill the joist space up about 4 5.

There are some unfinished crawl space areas in the corners on the upper floor. They are directly below the roof sheathing and are were insulated with fiberglass batts stapled between the 2x4 rafters. For rolled insulation place it between roof rafters. If you have a solid floor covering the roof rafters use the claw end of a hammer to pull the floor up in several locations and blow the insulation under the boards.

How to insulate 2x4 rafters. If your attic rafters are 2 by 6 inch framing members i assume you used an r 19 batt insulation. Box out light fixtures. Remember you ll need at least 1 air space above the insulation for attic ventilation.

I have a 1925 bungalow in michigan climate zone 5. R 19 is made for 6 inch framing and if you installed the vent trays properly there should have been enough air movement in the cavities to prevent condensation on the back of your roof sheathing without nailing extensions to the rafters.