A finished attic should be insulated much like the rest of the house with insulation in the walls and ceiling.
How to insulate a attic 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.
With a finished attic insulation must help keep the attic areas comfortable.
Materials commonly used for the insulation of the roof deck include.
Insulate your attic to keep your heating and cooling from going through the roof along with your monthly budget.
The technically correct approach depends on a number of factors.
Insulating the pitched roof.
Box out light fixtures.
Then blow another layer on top of the roof rafters.
If it is located in a conditioned part of the house also remember to insulate and air seal your attic access.
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.
Before insulating seal any air leaks and make roof and other necessary repairs.
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.
That means insulating the attic floor only not the walls and having vents in the roof.
It creates a breeding ground for mold and mildew and ruins the air trapping pockets that block heat flow.
Water is insulation s enemy.
You may also insulate your roof to help regulate the temperature in an attic that is a part of your living space.
How to insulate a finished attic.
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.
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.
Insulate and air seal any knee walls vertical walls with attic space directly behind them in your home as well.
Whether or not there is an inner roof lining and the total thickness of the roof structure.