I wanted to insulate the crawl space in our house. I bought Ultra Touch insulation which is made from post-industrial recycled denim from blue jean factories. It is easier to handle than fiberglass and also a "green" product.
Step 1: Materials
The material list is pretty simple. The insulation and supports was enough to cover 1200 sq ft.
23 rolls of R19 insulation
7 boxes of 100 insulation supports
Something to cut with. I had bread knifes, utility blades and bare hands.
light - headlamp, flashlight and work light.
Wire cutters, I used bicycle cable cutter to trim the supports where the bays were not 16" on center.
Step 2: Drag the Insulation Under the House
The cotton insulation needs to fluff up a bit to go back to its original loft. I cut open and set out rolls to let them expand. The ones that were sitting a while, were stuffed into the crawl space access door. It is best to have one person feed and another to stack them. The access door was small and it took a while to go from under the house to outside. It was easier to have all the materials under the house.
Step 3: Stuff Rolls Between Joists
The rolls are a bit wider than 16" which allows you to stuff them between the floor joists. They will fit pretty well just from friction but the supports are supposed to be 4" from the ends and 16" to 18" apart.
To install the supports just push up them up between the joists. The ends of the supports will dig into the wood and bow upwards into the insulation. Be sure not to compress the insulation too much, this will decrease its R-value.
To see how far apart to put the supports, I just held up a support lengthwise from the previous support since each support is about 16."
Step 4: Cutting Insulation
I would just roll out the insulation until it filled up a bay. Where I got to something like braces between joists, the insulation would have to be cut. Cutting was a bit tricky. I tried to saw all the way through with a bread knife. This worked well but took some time. I later used a utility knife to score the top layer and then rip the rest. In fact some of the rolls had a lengthwise factory cut about halfway through the roll. This could allow you to rip the insulation to about 9" wide strips to fit in areas that were not 16."
The best way was to just rip the insulation by hand. This was faster. It did result in a bit more uneven tears, but you could pull off chunks like pulling bread apart and stuff in the areas you missed.
Step 5: Repeat Until Finished
That is about it. Installing is very easy but it takes a while because you are crawling around on your hands and knees. It took about 9 hours with 2 people the whole time and 3 great friends who helped off and on.