Insulating Attic Joists

Although it s common to talk about installing insulation on the attic floor most attics don t really have a floor.

Insulating attic joists.

More insulation installation tricks and tips work from the perimeter of the attic toward the door or hatch so that you don t trample all over the insulation you just. If you decide on mineral wool such as glass wool or rock wool you will need to put down a damp proof membrane. Check the insulation manufacturer s instructions for the necessary thickness of plastic. No matter what kind of insulation you currently have in your attic one quick way to determine if you need more is to look across the span of your attic.

Fill the entire depth of the joists with insulation. When unrolled batting assumes its loft or thickness. 1a attic access door. Either batting or blown insulation works in attics.

They have floor joists or the bottom chords of roof trusses with drywall below. In unfinished attic spaces insulate between and over the floor joists to seal off living spaces below. So insulating the floor of the attic is not only the best solution but it is also the simplest and cheapest. Spread plastic sheeting over the crawlspace floor to block ground moisture from entering the area.

Overlap the seams by about 12 inches and run the plastic up the walls at least 6 inches. In practical terms you can choose between mineral wool or insulation boards. Batting comes in rolls and is sized to fit between rafters or joists. You can lay fiberglass sold in pre cut batts or rolls that you cut to size into the joist cavities or pour in loose fill insulation cellulose is the most common type although you can occasionally find glass fiber and rock wool.

Always cover the tops of the ceiling joists to make sure the insulation is deep enough to reach your target r value and. Standard joist spacing for the installation of attic flooring materials is 16 inches on center oc meaning the distance from the center of one joist to the center of the next joist is 16 inches. In an unfinishedattic the most effective method is to add insulation between the joists of the attic floor.