My home has R12 attic insulation laid in between the roof rafters. I'd
like to add another layer of pink to top it up. Which direction is the
second layer supposed to run? crossways (overlapping the first layer)
or the same direction as the first layer?
The second layer of batts should be installed perpendicular to the
first; installing them at 90 degrees allows you to cover the ceiling
joists and thus minimize any thermal bridging.
My attic had just two inches of fibreglass (R6). I added R13 on top
of this (which brought it to the top of the ceiling joists) and an
additional R40 crossways. This cut ceiling heat losses by
approximately 90 per cent.
The way to do it is to run it parallel with the first layer, but, use
some shears or a handiknife and plywood and cut one strip in half. You
can start so the strips are offset and cover the joists. Eventually
you will make up the space since you are on top of the joists. When
you get within a couple of inches of the joist use one of the half
strips to cover it up and then go back to the full size width. Doing
it this way you will not have any of the joist wood exposed like you
would at the joints where every perpendicular strip crosses all the
joists. Hope I made my self understood and good luck, RW
Get cellulose blown in. More "R" per inch, and it's fire resistant. I just
had phase one of my insulation put in today. Cellulose in the walls also.
And R-49 in the ceiling. (Kansas) Here's some good info:
"yeosmyth" < firstname.lastname@example.org> wrote in message
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