What you choose to do insulating with depends, to a large extent, on the conditions you’ve got to work with in the area that you are insulating. The DH also wants to do the ‘old/old’ part of the basement, which was built in 1939, has a positive jungle of electric wiring, ductwork, and water pipes in the ceiling. So, there are weird spaces, angles and just sheer ‘stuff’ to get around. For this, he felt that his choices were a) fiberglass insulating batts cut into pieces and b) expandable foam. If we were working in the summer, where we could open every window and door in the house, use fans to pull the chemical vapors out of the space and so on, he might have chosen the expandable foam. But we aren’t and we can’t and between the very little regular visitor who stays with us several days a week and our trying to hold onto every brain cell we still have, we went with the batts.
Now, we’ve worked with batts before and one of the real weaknesses of fiberglass batts is that they are NOT impervious to mice (well, at least we think they were mice; we’re hoping they were not chipmunks or anything, ahem, larger). And once mice (or whatever) start to tunnel through that stuff, the whole R-value just goes to heck.
I am still trying to figure out how mice can tunnel/chew through fiberglass and survive, or perhaps they are sacrificing themselves for the greater good (that is, opening up nice warm places for field mice to hole up for the winter). But the DH figured that there needed to be some sort of ‘sealing up’ of the batt needed to take place, just to keep the mice out. Now, we already know that sheet plastic will not stop mice (they are almost as effective as rats at chewing through plastic, Rubbermaid(tm) containers and so on) and though something approaching extruded wire mesh (like window screening) would stop them, it would not stop moisture from getting to the fiberglass and once fiberglass gets wet, it holds moisture next to wood floor joists like a magnet (which promotes mold and rot).
So, we’re going with 1/4″ plywood. We’ll give this a test right now and unscrew it later and see how the area has done. In the meantime, here is our own DIY star, the DH, showing you how he does it. In this demo, he’s working in the front NE corner of the house, which is probably the coldest spot in the entire house, which makes the room above it (where I am sitting right now) rather uncomfy at the floor level.
Step One: Measuring
Step Two: The Insulation
Step Three: Measuring and Cutting 1
Step Four: Measuring and Cutting 2
Step Five: Installing
Again, the list for what the DH was using for this:
Measuring tape
R19 Fiberglass batt
1″x1″ board as his straight edge
Retractable craft knife
Protective gloves
1″ wood screws
1/4″ plywood cut to the same size as the fiberglass batt
Electric drill with a screw-driver head on it.
