Thursday, December 11, 2008
Increasing attic hatch insulation
The attic hatches are a piece of particle board with an 8" thick piece of styrofoam insulation glued to it. Since the insulation in the attic was being increased, the insulation on the attic hatch needed to be increased so the hatch wasn't a weak area, from an insulation perspective. Here the 8" thick piece of insulation is being used as a pattern, and is sitting on top of a 1 1/2" thick piece of styrofoam.
I cut out two pieces of 1 1/2" thick styrofoam (using the 8" thick piece as a pattern), for a thickness of 3 inches. I took a thin piece of fiberboard, and fastened two 2x4 pieces on the sides (to help hold the fiberboard down on top of the attic hatch). I took two pieces of 1x4 and fastened the styrofoam to the fiberboard using 4" screws to go through the fiberboard, the styrofoam, and then into the 1x4s. For the top, I took some more styrofoam and fitted it between the 2x4s and had a few other scrap 1x4 pieces to hold those together. This photo was taken when the pieces were being test fitted.
Here the pieces were all assembled.
Here the extra hatch insulation has been placed on top of the bedroom attic hatch. It fits like a glove (perfectly). So the attic hatch now has 12 1/2" of styrofoam insulation above it. I believe this white styrofoam (technically: expanded polystyrene foam) is about R-4 per inch, so that makes it about R-50, so that should be good.