Insulating Attic Joists

If you decide on mineral wool such as glass wool or rock wool you will need to put down a damp proof membrane.

Insulating attic joists.

Check the insulation manufacturer s instructions for the necessary thickness of plastic. Either batting or blown insulation works in attics. Add new insulation if your attic has no insulation install either foil or kraft paper faced fiberglass rolls or batts in between all the attic floor joists which are also the ceiling joists of the rooms below. Spread plastic sheeting over the crawlspace floor to block ground moisture from entering the area.

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. 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. If your insulation is just level with or below your floor joists i e you can easily see your joists you should add more.

So insulating the floor of the attic is not only the best solution but it is also the simplest and cheapest. In practical terms you can choose between mineral wool or insulation boards. 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. Batting comes in rolls and is sized to fit between rafters or joists.

In unfinished attic spaces insulate between and over the floor joists to seal off living spaces below. 1a attic access door. When unrolled batting assumes its loft or thickness. Fill the entire depth of the joists with insulation.

Always cover the tops of the ceiling joists to make sure the insulation is deep enough to reach your target r value and. They have floor joists or the bottom chords of roof trusses with drywall below. If the air distribution is in the attic space then consider insulating the rafters to move the distribution into the conditioned space.