We have chosen to convert an H1 (low roof) van to ensure we have access to all the places we might want to go in it – from carparks to small country lanes etc . This means that there is not a lot of height to play with inside the van and we want to maintain as much of that height as possible during the conversion. This also means that a lot of thought has gone in to how best to insulate and fit the floor and ceiling.
After much head scratching, we have opted to bond wooden batons between the pressed stiffening ribs in the steel floor before fitting a plywood floor on top. These batons are only slightly higher than the reinforcing ribs, and had to be installed in sections to avoid raised weld seams running across the van floor. We tried to add batons as close to the walls of the van as possible and added extra around the sliding door, which will get a lot more traffic. We used Sikaflex 252 to bond the wood to the van floor and left it overnight to go off.
If you are considering using Sikaflex 252, make sure you have a decent sealant gun. It is quite thick stuff and requires some force to squeeze it out. We had a plastic sealant gun, which we’d had for years, that decided to break under the pressure with only 3 batons to go until the end of the job. Luckily a neighbour had a metal one we could borrow to finish the job before the adhesive went off in the tube. I think the borrowed gun was older than me, but was certainly built to last and despite a fair amount of rust, it did the job well. The metal gun also required less force to squeeze the adhesive out. On our next trip the DIY shop, we invested in a metal one of our own, which looks pretty bomb proof and is likely to be the last one we ever buy.
The clearance between the top of the ribs in the van floor and the top of the wooden batons was calculated to be just enough to allow a small amount of insulation. We had enough foil-backed foam insulation left over from the walls to cover the floor between the batons, and as it is self-adhesive, installation was simple. This seemed a good compromise between height and warmth, as it gives some insulation, albeit minimal compared with other surfaces. It will also provide sound deadening as a bonus.
The eagle eyed amongst you might notice a section in the corner by the bulkhead with no insulation. This is where the connection from the mains electric hook up will come in, so it was filled in once the cable gland was fitted and connected to the socket under the van. I will cover the electrics in a separate post, but in reality there are several jobs in progress at any one time.
Once the floor was prepped, it was time to cut out ply sections to screw down into the batons to provide a stable, level floor. We again made cardboard templates to get the shape right and transfer the correct profile onto the 12mm plywood sheets we bought for the job. The floor will be made up of 3 sections, and we started at the rear doors, where there are no straight lines and nothing is quite perpendicular, so it took a while to get it right in cardboard.
Once we cut the ply, we realised we had not considered the thickness of the material and the curve of the van walls in actually manoeuvring the ply sheet into place (12mm ply is not a flexible as cardboard!), so had to go back to the workbench and cut a bit more off before it would fit.
Armed with this additional information, the next 2 pieces were much simpler, but we did have to cut the middle section down from the full with of the plywood sheet to prevent the join between the second and third sheets from falling exactly on a small gap between batons (typical!). We were concerned that there would be too much movement if we fitted it that way, as there would be nothing to support the edges of the sheet.
With the addition of a hole in the rear sheet to allow access to the mechanism to lower the spare wheel from under the van, the floor was done. Cutting that hole took very little time, but in order to know what size to make it, I needed to find the tool which needed to fit in there. The jack etc was easily located under the driver’s seat behind a small plastic panel, but working out how to actually get all the tools out was akin to advance levels of Tetris. There must be an engineer somewhere who is very proud of their use of a small space in creating a 3D jigsaw puzzle for the unsuspecting future van owner.