If you know anything about by us now, you know that we research everything we do to the nth degree… well, as well as we can.
The same holds true for our quest to find the right insulation. When we took the interior of the bus apart, we swore that we wouldn’t even think about using fiberglass at all. The insulation we took out was awful, some of it was filled with dirt, some of was smashed to pieces, and a lot of it had gotten wet. As with most fiberglass, no matter how well you cover your skin, it finds a way to make you itch.
Initially, we thought about using spray foam, but that idea was quickly extinguished simply due to cost. Our estimate set the price of roughly 700 dollars, and that’s with us doing it ourselves… With it’s R value per inch(6.5), it can’t really be beat in terms of insulating properties
The next idea was using foam boards. There are several different types…
Expanded polystyrene foam – r value of 3.5 – 4 per inch
Extruded polystyrene foam – r value of 4.5 -5 per inch
Polyisocyanurate and polyurethane foam – r value of 7 – 8 per inch
With the curves of the ceiling and the cost of these options, we mostly opted out of them too but they are all good options as well.
We scored some expanded polystyrene 2ft x 4ft x 1inch sheets for free off a job that Blake was working at. They over ordered what they needed and we ended up being able to take some home with permission. While this isn’t going to be our main insulation, it will be utilized in several different areas of the bus!
With research, we hear about Roxul, a mineral wool fiber insulation with an r value of 4.2 per inch. It’s also fire-proof (it eventually melts at 2100 degrees, but never combust) and waterproof, both things we really like.
We were at the local ReStore and happened across a pallet of 7 bundles of 5inch thick Roxul marked down to 30 dollars a bundle. We immediately were shocked at that deal but they even knock the price down to $25 a bundle. We walked out of there with 90% of the insulation we needed for 189.90, tax included.
We never do it the easy way.
Blake crafted a holder for the insulation out of scrap wood. He cut the side walls to be 2″ high, which just below the middle of the insulation. At first we tried to use a wire to cut the insulation but couldn’t keep it tight enough to make the cut consistent so Blake fashioned a cutting harp out of scrap wood and the wire. We went back and forth together in a saw like motion on each piece twice. This gave us two 2″ pieces and one 1″ piece.
Once we finished cutting down the sheets of insulation, we started fitting and installing them on the ceiling of the bus using box cutters. One sheet fit one in between the ribs with a small gap horizontally and excess insulation vertically. We would just cut the excess and fill in the holes. We were able to use the 1″ pieces of insulation folded in half to make 2″ or pieces of it to fill in space. Somehow, we the amount of insulation we bought (which was all that ReStore had) was the perfect amount we needed. We were able to insulate the walls and ceiling using the 7 bundles.
There was difference pretty quickly.