Anyone have any experience with this stuff? I'm trying to replace the
old scuttle panel for access to my attic with a contraption that I am
trying to make out of some 2" (thickest I could find) foam board and
Masonite. Reason for doing this is that my bedroom closet gets very
cold in the winter, I ASSume because the ceiling is well insulated but
the panel is just very thin plywood. 2 questions:
1) It appears that in an effort to make a tight fit, I cut the foam
board just a little big. Is there an easy way to shave it down a
little? It doesn't "shave" well with a knife. Am thinking Surform
file? Or will that just make a mess?
2) What do you use to glue it? I'm trying to laminate three pieces
together for better insulation (the bottom most piece will be hanging; I
cut it slightly smaller so it'll fit in the "jamb" area of the scuttle
hole. That one will be faced with Masonite for a finished appearance.)
construction adhesive isn't doing it (I put 8-10 dots on there.) Should
I just use more construction adhesive, or is there something better?
replace "roosters" with "cox" to reply.
I just have a scuttle hole in the hall- after I had 8 inches of
loose-fill insulation added to attic, I built a dam around the topside
of scuttle hole out of 1x8 (including a place to park my butt as I climb
off top step of ladder), so as to not get avalanches every time I opened
the attic. I then cut 2 sheets of 3/4" foamboard and taped them
together, to lay inside the dam I built, as I climb down. I also taped a
sheet of foamboard to the top of the finished lid that sits in trim on
hallway ceiling. This gives me about a 6" dead air space between the
layers of foamboard. You want the bottom lid to be a tight fit in the
hole, sort of like a cork in a bottle. I added a handle facing down into
the hall, so I could pull the lid down tight. It is a bit of a juggling
act getting it all closed up, but it works. Not a real good job- this
was just a quick and dirty with stuff I had laying around. But it does
make a noticeable difference. One of these days I need to redo it with
better foamboard, trimmed more carefully. Maybe, instead of a drop-in
upper lid, one with 2 layers of 2" thick foamboard glued or bolted
together with a rabbited edge that fits the wood dam tightly, and a
handle on the bottom to pull it snug, like the lid below it. I raked the
insulation up against the dam I built, but another layer of foamboard on
the outside of dam, down to the buried attic floor, would probably help.
Cut easily on a table saw if you have one, or even with portable
circular saw (although may take a pass from each side). Surform will
work and will make a mess.
Use foam board adhesive. Regular construction adhesive will often
dissolve the foam.
To cut it go to a hobby store. They have a little tool that looks
similar to a coping saw except it has a wire (like a guitar string)
and it takes a couple D batteries. The wire heats up and glides thru
the foam. This little gizmo works great and is less than $10.
Believe it or not, elmers glue will work fine. Hobbyists use it for
such applications. You can try 3M's 777 (triple 7). Try a test piece
first. If it doesn't eat the foam, it would be better.
eventual resolution - I took it out on the deck and used a belt sander
to knock it down. Worked OK as long as I kept the sander at about a 45
degree angle to the board, otherwise it'd chatter.
Had a tube of PL premium that had been kicking around way too long, just
used about half the tube, that seems to have done the trick
put half the plug in the scuttle hole overnight and it got down to about
20 degrees, when I popped it up to tidy up in the attic this AM the
topside was cold as heck but the surface of the Masonite felt warm.
That's a good sign. Was only two layers (R-20) whereas my final
assembly will be 3 layers and should be about R-30 so hopefully this
will solve the cold closet problem. (attic was probably colder than
previously as well because 2 of 3 attic vents had birds' nests in them,
which I removed and re-screened while I was up there.)
I did see the recommends to build an insulation dam around the opening,
but I'm out of foam board so that'll have to wait for another day. Good
I also saw the post about using fiberglas batts, you have no idea how
much I hate fiberglas insulation and how much nicer I find solid foam to
be. Personal preference I guess.
replace "roosters" with "cox" to reply.
Even better, I found a jigsaw blade that was essentially a knife - no
teeth, just a sharp edge. That thing went through foam board like
butter - I was using it for building concrete forms for countertop.
I'm guessing the knife edge kept the cut smooth, and the friction from
the blade moving heated it up enough to make it cut smoothly and not
catch little bits like a standard razor blade will.
that sounds like the ticket, if I have another project that requires
foam board I'll keep an eye out for those.
The day I finished my scuttle plug, it got down to mid-teens that
night (that's quite cold for this area) so I was happy to have done
it! Bedroom closet stayed noticeably warmer, despite my having
cleaned out the attic vents.
When this material was new, the favourite tool to cut
it was an electric carving knife. The edges will always
crumble, but the elec. carving knife can be held more
steady than other tool, which reduces crumbling.
You can cut foam cleanly with a bandsaw. Not sure which glue is best
I made a corregated cardboard box cover for my attic staircase and
fastened a fiberglass batt on top using duct tape. It fits over the
pull-down stairs. After several years the edge of the box began to
fray so I glued a thin strip of pine around the edge. On the trap
door itself, I put a sheet of styrofoam and protected that with thin
hardboard (so the foam would not be damaged from shoe tips on the
ladder. Not pretty, but it is lightweight, out-of-sight, and
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