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.
How to properly insulate an attic ceiling.
Set up a stepladder tall enough to work comfortably from.
If only the living space will be insulated wrap the insulation around the room s walls and ceiling and then continue along the floor of the non living space.
Because the simplest and cheapest way to insulate an attic is to add material to the floor.
Purchase rolls or packages of insulation that will fit in the spaces between the ceiling joists.
Plan to pull up the flooring and layer new insulation on top of the old.
Use the insulation calculator to plug in your zip code lifestyle factors building design energy costs and budget to get a detailed recommendation.
Most codes require a specified minimum amount of headroom and it s tough to meet this requirement when insulating a finished attic especially since most codes require insulation equal to r 38 or more.
Ensure ends of insulation are butted together and flush to underside of framing.
While wearing dust mask and gloves carry r 38 batts of unfaced fiberglass insulation into the attic.
Insulating a finished attic there are two basic ways to insulate a finished attic.
The standard width for joists is 24 inches.
From the drywall depending on the insulation type.
Ensure insulation extends to the outside edge of the exterior top plates and is flush against any ventilation dams baffles.
The recommended ceiling insulation level for most attics is r 38 or about 12 to 15 in.
Lay the batts across the ceiling joists covering the existing insulation.
In this case the area behind the knee wall will be uncomfortably hot or cold.
But if the floor is covered in plywood you can t stuff enough insulation beneath it to do the job sufficiently not even in warm climates.