There are two basic ways to insulate a finished attic.
How to ventilate and insulate an attic finished.
Hot air exhaust vents located at the peak of the roof allow hot air to escape.
Cellulose is has an r value of almost 4 0 per inch.
With this method you ll need to run vapour between each joist below the insulation.
The insulation is spray foam open cell directly on the underside of the roof deck min r19 and on the inside of the exterior walls.
There was ridge vent originally installed but sealed up with spray foam closed cell.
The attic floor which is the ceiling of the living space below often already is insulated.
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.
The soffit vents allow convective air movement from the soffits of the residence to the ridge vent.
Permanent stairs carpet heat ceilings drywall completely finished.
The soffit vents are installed at the eaves which allow fresh air to rise up and along the.
Fiberglass insulation has an r value of roughly 3 0 per inch of thickness.
Take care around electrical fixtures and heating vents.
In addition insulation baffles must be installed at the point where the attic floor meets the roofline to prevent the attic insulation from migrating into the cavities and restricting the airflow from the soffit vents.
In warmer climates an r value of 30 is recommended.
When insulating an attic you should also consider how your attic is.
Since parts of a finished attic are usually very close to the roof insulation often blocks proper ventilation that is needed under a roof structure.
Intake vents located at the lowest part of the roof under the eaves allow cool air to enter the attic.
5 year old house finished attic.
If there s no floor start the insulation between the floor joists and add more on top the second layer of batts should be perpendicular.
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.
Whoever finished off the attic should have installed soffit vents and soffit chutes and a ridge vent.
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.
In this case the area behind the knee wall will be uncomfortably hot or cold.