Roofing insulation gets installed on the roof slope, above and below the rafters, while attic insulation is installed in the ceiling pane. Roof insulation is especially vital if your home has a ...

A: You are correct and your girlfriend is wrong. Insulating between rafters will do no good, because the attic should be ventilated, and the rafter insulation would be between two unheated spaces.

You should lay an appropriate (usually R-30) insulation on the attic floor, but avoid tucking it down into the area where the roof rafters meet the top of exterior walls and joist.

This means you can have a combined R-value ranging from R-23 to R-31 with only 5-1/2 inches of combined fiberglass and foam insulation. Why Your Roof Needs Air Chutes ...

The insulation can be cut to fit around ceiling joists and rafters, but will not provide the same seal that spray foam insulation offers. It is a good low-cost option with average costs ranging ...

However, I do have a concern about spraying foam directly on the underside of the roof sheathing and rafters. Closed cell insulation will not allow water to pass through it.

The city building inspector in Concord, New Hampshire, suspects faulty connections between the rafters and the attic joists caused the roof of a two-story Colonial to slide off last week.Click to ...

The materials used to insulate under the roof include batts of mineral or glass-wool insulation, held in place by battens of wood attached to and across the rafters. Alternatively, polystyrene slabs ...