How To Extend Roof Rafters For Insulation

Attach 1 2 inch wood cleats to both sides of the existing rafter.

How to extend roof rafters for insulation.

The paper will fold over the rafter framing thereby allowing for attachment with staples. If 180mm is to be installed then 100mm board might be introduced between the rafters there has to be a minimum 25mm air gap between the insulation and the underside of the tiles or slates with an 80mm board running across the rafters. Ceiling joists are the horizontal boards that span the width of the house resting on the outer wall plates and possibly on. The rolls have a number of 8 foot pieces rolled onto one roll.

The fiberglass insulation comes in rolls that are 16 to 24 inches wide. 2d extend insulation into joist space to reduce air flows. It works well to increase the r value and furring strips and then drywall can be applied. In finished attic rooms with or without dormer insulate 2a between the studs of knee walls 2b between the studs and rafters of exterior walls and roof 2c and ceilings with cold spaces above.

The insulation should be installed with the paper facing out and attached using staples. When installing 2 by 4 lumber to existing 2 by 6 rafters add the 2 by 4 width which is 3 1 2 inches to the 2 by 6 width which is 5 1 2 inches for a total of 9 inches. Use cleats the same length as the width of the new rafter when added to the width of the old rafter. While roof overhang depth can differ depending on the style of the home standard overhangs extend outward about 24 inches.

With a warm roof the usual process is to split the insulation into two layers.