Whether or not there is an inner roof lining and the total thickness of the roof structure.
Insulating a attic roof.
Typically you will fill the insulation blower with the insulation and blow it between the attic floor joists.
It can be installed in one of two places.
If you have a solid floor covering the roof rafters use the claw end of a hammer to pull the floor up in several locations and blow the insulation under the boards.
On the attic floor or beneath the attic roof.
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.
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.
Insulating in and around your roof attic space also prevents long term damage from moisture build up or ice damming which results from the warm air trying to escape through the apex of the roof but instead heating up the snow.
That means insulating the attic floor only not the walls and having vents in the roof.
How to insulate a finished attic.
A finished attic should be insulated much like the rest of the house with insulation in the walls and ceiling.
Senior engineer manager at icynene john broniek makes the case for the unvented attic assembly and why insulating the underside of the roof makes sense.
It creates a breeding ground for mold and mildew and ruins the air trapping pockets that block heat flow.
Insulating the roof is a priority if the ceilings of your home happen to be part of the roof deck as is the case with cathedral ceilings.
Materials commonly used for the insulation of the roof deck include.
If you re finishing your attic insulating it to the proper r value can cause a dramatic loss of headroom if you limit yourself to fiberglass batts.
Additionally insulation serves as a way to enhance sound proofing on the uppermost envelop of your house.
Then blow another layer on top of the roof rafters.
Water is insulation s enemy.
Insulating the pitched roof.
Box out light fixtures.
The technically correct approach depends on a number of factors.
To meet all three goals insulating your finished attic ventilating the roof and maximizing headroom use a combination of dense batt insulation rigid foam sheeting and air chutes.
You may also insulate your roof to help regulate the temperature in an attic that is a part of your living space.
Installing attic roof insulation instead of attic floor insulation has several benefits.