Re-insulating the walls of your skoolie conversion is important. For a few reasons:
- The insulation currently in there is nasty, old, and not really doing much anyway.
- You want to inspect and make sure there are no leaks in the lower walls
- Re-insulating with a higher R-value insulation will help A LOT with heating and cooling your school bus conversion
What type of insulation should I use?
That really comes down to preference! We chose Rockwool Mineral Wool Comfort Batt (you can get it at Lowe’s) primarily because of its high R-value and moisture resistance. It also has the added benefit of being a great sound absorber, which helped greatly in soundproofing the recording studio. Many skoolies choose spray foam; that application didn’t work for us because of cost and also because it’s not great for sound absorption.
This tutorial is only applicable for insulating with a batting insulation material.
Tools & Materials Required:
- Your chosen insulation material
- An insulation cutting knife (or a bread knife)
- A long hand saw (we used only the insulation knife and wished that we had used one of these as well)
- Sharpie marker
- Gloves and masks
- Impact driver (we got this drill/impact driver combo kit and it served us well through the whole conversion!)
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Step 1 – Construct a cutting box
- The insulation we bought came 3.5 inches thick. The lower part of the walls in 2 inches thick. We could have compacted it to fit, but this will result in lost R-value. So we decided to reduce the thickness of each piece of insulation for the lower walls. To do this:
- Build a three-sided frame that matches the width and length of your insulation. Construct it with wood cut at 2″ width. It will look like this:
Step 2 – Cut the pieces of insulation for the lower walls
- Go section by section.
- Measure the width and length of the section, then cut the insulation with an insulation knife to create your insulation panel.
- Cut in short motions back and forth (not long, sweeping cuts). Cutting in a short back-forth motion will make a clean cut with very little pulling of the material.
- Now you need to make the insulation panel 2″ thick. Place the panel inside the frame and cut along the top of the frame, resting the saw along the frame as you cut. Like this:
Step 3 – Insert the insulation into the lower wall sections
Okay, here’s the deal. In the above video, you see me using a piece of wood to squeeze insulation into the lower part of the walls. That was dumb. I thought it was necessary because of screw ends sticking into the lower wall from exterior rivets. Again, dumb. It turns out that those screw ends were from…well, screws.
SO. We ended up removing the insulation Norlan and I put in the lower walls (it was all squished and messed up from my wood ploy). Then we did this simple installation method:
- Go outside. With the impact driver, remove each screw. Keep them together in a bucket or bag.
- Insert the panel you cut to match the section of lower wall (it will slide right down).
- Repeat for all sections of lower wall.
- Replace the screws.
Step 4 – Cut and install insulation for rest of wall space
- As you see in the video, we kept the original 3.5in thickness of the insulation for the main part of the walls. So there’s no need to use the frame for this step.
- Just measure the section of wall, cut the insulation to match(adding .25 inch on each side), and plop it right in. If you’ve done your measurements correctly and added that extra .25 inches on each side, it should fit snug enough to hold itself up.
- Insulation isn’t cheap, so it’s worth the extra brainpower to play tetris when cutting your different sections of insulation. Try to use up the whole panel, rather than having lots of extra pieces!
Step 5 – Use leftover pieces to fill upper walls
- Use all the extra pieces to fill in the cavities in the wall space above the windows. Have fun with it! Treat it like 3D tetris!
Congrats! Your walls are done! Now go take a shower, ’cause chances are you are super itchy from that stuff! Next up, framing out and laying the electrical lines in your walls!