Attic Insulation Rafters Or Joists

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.

Attic insulation rafters or joists.

Improving your home s energy efficiency rating. Water is insulation s enemy. The technically correct approach depends on a number of factors. Other benefits of roof insulation include.

If you leave these uninsulated then the heat will bypass your new insulation making it largely ineffective. Whether or not there is an inner roof lining and the total thickness of the roof structure. Clear the joist spaces. Rafters are the building components that run diagonally from the wall plate to the apex of a roof structure.

Ceiling joists are the horizontal boards that span the width of the house resting on the outer wall plates and possibly on. Also remove any blocking or bridging between the joists as applicable. It creates a breeding ground for mold and mildew and ruins the air trapping pockets that block heat flow. Box out light fixtures.

You will need a baffle for each space between the rafters. Pull any existing insulation away from the edges of the attic where you will be putting up the baffles. Insulating at rafter level is considerably more expensive than most standard loft insulation. Some companies may offer.

Look for water stains on the roof sheathing or damp or moldy spots on attic joists and existing insulation as a clue to where leaks might be. If your attic is often used or perhaps you plan to convert it in the future you will need to insulate the inner surfaces of the roof. Rafters form the foundation for attachment of the roof boards onto which the final roof covering is fixed. Standard joist spacing for the installation of attic flooring materials is 16 inches on center oc meaning the distance from the center of one joist to the center of the next joist is 16 inches.

Pull out all insulation and any debris from all of the joist spaces so you can see the full length of each joist including where it meets the exterior walls. In traditional timber they are nominally 2 inches thick and typically 8 to 10 inches wide. For a correct approach an inner roof lining is required. As well as insulating the roof you will have to insulate any gable walls party walls and chimneys in the loft space.

2d extend insulation into joist space to reduce air flows. Insulation between the joists keeps warmth in your living space below and creates a cold loft while insulation in the rafters allows you to keep warmth in the roof space as well. Fit each one snuggly in the bay with the bottom starting where the ceiling joist meets the roof rafter.