If your attic floor has no insulation install faced batts or faced rolls between each joist with the moisture barrier facing down against the drywall or plaster ceiling below.
How to install insulation in ceiling joists.
If you want to install standard r 38 insulation.
Run the unfaced strips perpendicular to the.
How to install insulation between floor joists.
Align the front of the board with the face of the rafter or joist.
Measure the depth of the existing insulation between the ceiling joists in the attic.
Hold the batts in place by stapling their paper faced vapor retarders to the lower edges of the joists.
If using faced insulation keep the paper vapor retarder facing up and against the subfloor.
The insulation should fit snugly against the subfloor and between the joists.
Leave an air gap between the roof sheathing and the board.
Start at one edge of the crawlspace and install the insulation between the floor joists.
Set up a stepladder tall enough to work comfortably.
The standard width for joists is 24 inches.
The ceiling joist system is typically constructed from substantial two by tens or larger dimension boards but some older homes have smaller joists.
When the basement or crawl space.
If there is already insulation between the joists increase the r value by installing unfaced roll insulation right on top.
Multiply the depth in inches by 3 14 to determine the r value of the existing insulation.
Joist bays the open spaces between floor joists are prime hosts for insulation under specific circumstances.
Press the cut insulation board to fit between the rafters or joists.