Attic Insulation Rafters Or Joists

Improving your home s energy efficiency rating.

Attic insulation rafters or joists.

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. You will need a baffle for each space between the rafters. How to increase the interior ceiling joist for r38 insulation. Fit each one snuggly in the bay with the bottom starting where the ceiling joist meets the roof rafter.

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. Box out light fixtures. If you leave these uninsulated then the heat will bypass your new insulation making it largely ineffective. 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. Some companies may offer. Also remove any blocking or bridging between the joists as applicable. Whether or not there is an inner roof lining and the total thickness of the roof structure.

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. Other benefits of roof insulation include. Pull any existing insulation away from the edges of the attic where you will be putting up the baffles. 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. Rafters form the foundation for attachment of the roof boards onto which the final roof covering is fixed. Water is insulation s enemy. As well as insulating the roof you will have to insulate any gable walls party walls and chimneys in the loft space.

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. Increasing your home s value. 2d extend insulation into joist space to reduce air flows. It creates a breeding ground for mold and mildew and ruins the air trapping pockets that block heat flow.

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. 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. The technically correct approach depends on a number of factors.