How To Ventilate And Insulate An Attic Finished

The attic floor which is the ceiling of the living space below often already is insulated.

How to ventilate and insulate an attic finished.

Ventilation the best method for ventilating any roof is to have some type of venting up high on the roof that allows for rising hot air or warm damp air to escape. When insulating an attic you should also consider how your attic is. The soffit vents allow convective air movement from the soffits of the residence to the ridge vent. Whoever finished off the attic should have installed soffit vents and soffit chutes and a ridge vent.

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. There are two basic ways to insulate a finished attic. In warmer climates an r value of 30 is recommended. There was ridge vent originally installed but sealed up with spray foam closed cell.

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. Hot air exhaust vents located at the peak of the roof allow hot air to escape. Fiberglass insulation has an r value of roughly 3 0 per inch of thickness. In this case the area behind the knee wall will be uncomfortably hot or cold.

With this method you ll need to run vapour between each joist below the insulation. Permanent stairs carpet heat ceilings drywall completely finished. 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. 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.

Cellulose is has an r value of almost 4 0 per inch. In colder northern climates an r value of 49 is recommended for adequate attic insulation. 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.

The soffit vents are installed at the eaves which allow fresh air to rise up and along the. Take care around electrical fixtures and heating vents. 5 year old house finished attic.