The insulation is completely done! We don’t have to look at that awful orange stuff anymore. Everything looks so nice and clean inside. It’s really starting to come together.
We used 1″ polyiso rigid foam board for the walls, ceiling, and the floor. This is over the top of the existing orange insulation that was already in the bus. There’s no such thing as too much! The bus is starting to look like a space station with all of the reflective silver everywhere…
There are a lot of special requirements for installing a wood burner in a bus or van. The owner at Unforgettable Fire (who sold us our Kimberly stove) walked us through everything we needed to know for safety.
For starters, the stove pipe cannot / should not have a shoulder joint like what we had hoped for to go out the side of the bus instead of the top. This is so that the smoke will be lifted up and out, and not build up unnecessary creosote inside, which is a fire risk. It helps with the air draw.
Then the materials around the stove (in the ceiling, wall, and floor) need to be able to handle high temperatures. XPS foam board near a stove that gets too hot will melt and release toxins into the air. Very bad! The recommended insulation is ceramic, which is this thick mat of spun ceramic fibers. It can handle very high temperatures and disperses the heat. Over the top of the ceramic should be concrete board for it’s heat resistance. This should all be secured with high heat resistant adhesive.
The stove itself should have a six inches of clearance around it and the stove pipe.
This changes our plan a little bit, but we can be adaptable since it is for safety. 🙂 We removed the foam board from the wall and ceiling with a (minimum) six inch clearance around the stove and pipe.
For the ceiling – we will wrap the pipe in six inches of ceramic, and fill the rest of the space with denim insulation (the blue stuff).
For the wall – we filled the empty space with denim insulation, held in place by plywood. Over that will be a second layer of ceramic insulation, then concrete board.
For the floor – first we had to deal with the issue of the tracks in the floor. The tracks are slightly raised, and make an uneven surface to work with. To fix this, we re-applied a square section of the original rubber flooring, which raised it back up to the track height. Over the top we did two layers of plywood to prep the space for concrete board.
You can see from the photos that the fire space is still recessed a bit below the level of the floor, but this will raise up even higher when we install the concrete board and finish with tile over the top.
This is what denim insulation looks like. It looks great! We can immediately notice that sound seems more muffled, and the space feels so much warmer and cozier than before. It fits great into all of those odd nooks where foam board won’t. The only downside is that it sheds little blue bits of fluff everywhere…
It’s finally time to buy some insulation! We searched and searched for an insulation we could use for the floor with a high R value and high compressive strength (what we wanted was the pink Foamular foam board), but could not find a supplier anywhere on the West coast for the small amounts that we needed. After some discussion and research, we came to the conclusion that we don’t actually need crazy high compressive strength. We’ll be laying plywood above the foam board, using a soft, sound deadening mat over the top of that, and then laminate flooring. The weight of us walking on our floors just wouldn’t produce high enough pounds-per-inch to crush the foam board. So we are using 1″ Polyiso for both the walls and the floor.
We are also going to use soft denim insulation to replace the old fiberglass that was stuffed into odd corners and nooks. Neither of us like the idea of fiberglass, and denim is the perfect solution. It’s such a fun material, I just want to build a big soft nest out of it. 🙂
Mini road trip to Home Depot and Lowe’s in the Cuddlebus!