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.

Attic insulation rafters or joists.

Rafters are the building components that run diagonally from the wall plate to the apex of a roof structure. Some companies may offer. Insulating at rafter level is considerably more expensive than most standard loft insulation. How to reinforce an attic floor with sister joists.

It creates a breeding ground for mold and mildew and ruins the air trapping pockets that block heat flow. You will need a baffle for each space between the rafters. Rafters form the foundation for attachment of the roof boards onto which the final roof covering is fixed. Water is insulation s enemy.

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. If you leave these uninsulated then the heat will bypass your new insulation making it largely ineffective. Pull any existing insulation away from the edges of the attic where you will be putting up the baffles. Box out light fixtures.

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. 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. As well as insulating the roof you will have to insulate any gable walls party walls and chimneys in the loft space. Whether or not there is an inner roof lining and the total thickness of the roof structure.

2d extend insulation into joist space to reduce air flows. For a correct approach an inner roof lining is required. 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.

Ceiling joists are the horizontal boards that span the width of the house resting on the outer wall plates and possibly on. Clear the joist spaces. How to increase the interior ceiling joist for r38 insulation. Improving your home s energy efficiency rating.

Increasing your home s value. Also remove any blocking or bridging between the joists as applicable. Fit each one snuggly in the bay with the bottom starting where the ceiling joist meets the roof rafter.