Ambulance Turned Camper Van - How to Insulate the Floor

Last year, I started turning an old ambulance van into a camper. This is of course a project that is never finished and it is also a large project. It is always very helpful to see the descriptions of other people's projects and experiences which is why I also want to share mine with you in the hopes that you find it interesting and helpful!

If I can keep up the motivation and can define some topics that make sense to present in an instructable, this will become a series of articles to keep it detailed and focused on single topics.

Depends on the decision you're going to make for your type of insulation.

It will probably involve

• insulation material
• wood for a support construction of your later interior builds
• floor top
• end strips for any open ends
• various screws
• adhesive
• anti-rust colour, conserving stain for the support construction wood

There are so many different choices to cover your floor and put an insulation below! Really hard to choose - looking at functionality, materials of floor or insulation, style, etc.
Even before you start planning though, you should be aware of your restrictions that may influence your choice of insulation, floor material and choice of style.

Height
Depending on the height of the car you've chosen or any already installed furniture that you want / have to leave in the room, you might have a restriction on the total height of your floor layers. In our case there were some drawers we wanted to keep and therefore the restriction of the floor was to amount to max. 24 mm in total over all layers. Don't forget to include a buffer because it is very common - especially in older vehicles - for drawers to slump.

Weight
There may be some weight restrictions you have to adhere to regarding the total weight of the car (including buffer for loading). It helps to know the weight after stripping down the car to the minimum and know the max. weight all the potential drivers of the camper are allowed to move.

Insulation Capabilities

Different materials have different insulation capabilities. Our vinyl floor top is actually not that brilliant for it but to make up for it we have 20 mm of polysterene foam below. A floor top made from cork tree has a way better insulation value but usually the boards are thicker and also it may not be as scratch resistant.

Style Preferences
Of course, different materials will provide different looks. In case you have a very specific style already in mind of course you will also take colour and structure in mind. But this might also restrict you in the other areas.
But you should always be aware that the floor is also rather strongly determining the overall look.

Resistance
The floor is also a heavily used object in the camper and the material you are using should be able to keep up with your preferred activities. For us it was important to have a water and scratch resistant floor cover on top.

As you can see, there are many factors to consider. Usually, you will end up with a base below and a type of floor cover on top. In the end, we had 2-3 possibilities per layer and you can simply calculate weight and height (and price probably as well) of your combinations and choose accordingly. Don't forget the other factors though, they are also playing an important role in the life of your camper!

Remove the old floor and any other materials e.g. holders. Sand down larger bumps and remove most of the dust. If your camper van has any holes in the floor, close them (e.g. with adhesive). If the hole contains a metal ring or screw threads, sand them down and treat it with anti-rust colour in order to prevent oxidation.

In order to increase the stability of our benches and our bed, we put in a support construction which will go between the insulation material. This requires detailed planning before you start. We have been using 18 mm construction wood which you can get at the local store. But this also depends on your insulation layer thickness.

Before fixing the support construction to the floor we used some conserving stain to prevent the wood from rotting.

We chose polysterene foam as insulation but there are many other things you could use. We chose this one because it is very stable when walking on top of it but you could easily use armaflex with a thin wooden board on top as well. We also insulated the wheel-arches.

We chose a vinyl floor top, therefore we lay also a steam break (a kind of membrane to stop water from getting through to the insulation layer.

You will probably end up with some open ends where you can see the layers of your floor. We used end strips made from aluminium to close those edges.