How To Insulate A Ceiling Without Attic

The overall r value of the ceiling or a wall will also be somewhat different than the r value of the insulation.

How to insulate a ceiling without attic.

In an attic without soffit vents you can add insulation in the corners and the wedges between the slope of the roof and the floor of the attic which serves as the ceiling for the room below. If you put cellulose up there it will help insulate but you need a vapor barrier above the ceiling because you ll have warm ceiling air hiiting colder roof surface and condensing which will turn the cellulose into a moldy mess. Why attic insulation r value matters for california homeowners at this point you may be wondering why this r value matters so much especially when it s for an attic that you probably go into once a year to fetch your christmas decorations. For diy attic insulation you ve got two choices.

For instance compressed insulation will not allow you to know its full r value. Loose fill or batt the common term for blanket insulation. Both can be added to uninsulated attics or layered over existing material. Rolls of either glass fiber or loose fill cellulose are the most popular materials used by diy installers.

Nail 1 furring along every rafter side against the roof deck. Once you ve decided which type is best for you examine the material options and prices to home in on the right product. Cut and insert 1 or thicker high r foam insulation sheets r 8 per inch against the furring giving a 1 or greater air path between the insulation and the roof deck under the cathedral ceiling. Chemicals are then added to the insulation in order to provide fire resistance.

If the finished attic is simply a storage area without the need for climate control you can leave the attic floor insulation in place but must forgo adding anything between the rafters. Cellulose or wood fiber insulation is made from used newsprint other paper feedstock or wood. An attic you want vented but in your case you want the ceiling roof space sealed.