Bus Build: Adding Floor Insulation to our Bus Conversion – S03E02

Our bus won't start, NO!!!! Well, something has drained the batteries, so while we wait for them to charge up we carry on with work.

Before we can put our subfloors down we wanted to make sure we insulated the floors where possible.

We had kept some of the floor insulation that was in the back of the bus, near the engine.  We took it out, let it dry (as there was a leak around the restroom area), vacuumed it and put it back in.  It is a soft black rubbery foam sheet that we assume must have sound absorbing insulation as it was only used near the engine.  We had taken out fiberglass insulation in some areas plus there is the hollow air ducts from the air conditioning. We are not using the original aircon, so it seemed best to fill in these ducts with foam board insulation to prevent any air or moisture coming up into the floors and then seal the cracks and gaps with spray foam insulation.

In order to put our floorboards down we had to make a floor plan diagram and triple check our measurements before cutting the plywood.

The width of the inside of our bus is 8 foot 2 inches, a standard piece of plywood is 8 x 4 foot. That means we would not be able to add subfloor using just 8 x 4 plywood sheets across the width of the bus, but would have to cut several sheets measuring 2 foot 1 inch for the subfloor sides and an 8x4 down the middle of the bus (See our video for a diagram of this).

This was all made more difficult by the fact that we needed our subfloor boards to align with the bus floor frame to have something to screw the wood into.  So this required lots of measuring and cutting the boards to size.


Up Next
We get the center floorboards down, but not without trial and error.

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Spray Foam Insulation
​It forms a long-lasting, airtight, water-resistant seal. It helps keep insects, moisture/condensation and allergens out. Adheres to wood, metal, masonry, glass and most plastics.  We used these cans just

By Mela & Don

Mela and Don are sharing their journey as they make conscious decisions to live a more healthy, environmentally friendly life together.


  1. In previous episodes you mention using an Auto-cad Software to design the Interior Layout. What Brand of Auto-cad Software was it, What was the cost and how Easy/Difficult was it to Use?

    I’m looking at buying a 1979 MCI MC-9 which has a “decent” Interior even though it was a Musical Tour Bus for a number of years ago having minimal Amenities and Bunks instead of a Bedroom.

    Keep going. Your Videos are very informative.

    Thank You in Advance

    1. Hi Mike! I’m so glad our videos have been helpful. We used Fusion 360. There is definitely a learning curve involved if you haven’t used 3D software before. It is free if you are just using it for personal use, but they charge professionals. So we were able to get it for free and did have to invest time into learning to use it. Sounds like a sweet bus you’ve found!

  2. Don Remember the bus is 24 volts not 12 volts. You havent started yet so stay together and have fun. You talk aabout a dish washer big waste of money and remember you need lots of water ok if you are in a RV park but not always in one. How are you going to heat your water??? ther is so much to think of Check youtube for people that have converted other buses that will help. Last pleased turn your music down it is too loud…

    1. Hi Bruce! We’ll have a separate electric system for lights and power, won’t be using the bus batteries. And yes! Absolutely, lots of water so we can stay off grid. That’s the bonus of having large luggage bays – lots of space for water tanks.

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