In my last post I laid the floating subfloor. This is three plywood sheets cut to fit the shape of the van which are screwed in to batons secured to the floor of the van with 3M 4200 Marine Adhesive. Between the batons and the plywood sheets there’s a thin underlay to provide a small amount of noise, heat & sound insulation.
Since the last post I decided to upgrade the side and rear entries by buying the plastic entry trims. As a result I needed to cut back the subfloor at the rear. The top plywood was easy but 3M 4200 does an outstanding job of securing plywood to metal so trimming the battons was a dirty job. In the end I found dousing the adhesive in isopropyl alcohol and then rubbing very thoroughly with a rag was the best way to clean up.
Cutting and trimming the vinyl
This is a straightforward but time consuming task. First I laid out the vinyl in an quiet car park, laid the ply boards on top and made a very rough cut all around. I left at least an inch of extra to be trimmed in place. When rolling the trimmed vinyl back up I was careful to clean any debris from the back. Ideally I’d have laid everything out on a sheet.
Now that the vinyl can be laid in the van the real work begins on carefully trimming around all of the small intrusions into the van. In a Transit these are numerous: the wheel arches, front and rear pillars as well as two central access points on either side. For this I used both a good, sharp craft knife as well as high quality shears. Be careful not to mark the van or floor with the knife/shears but most importantly repeated smaller cuts are better than larger ones. Be careful to keep going and checking other areas of the van as it is surprisingly easy to move the whole vinyl sheet before a minimum amount of trimming to fit has been done.
Surface prep work
Prep work is largely split into three categories:
- Polyfill any imperfections in the floor
- Fill the edges where the plywood was deliberately cut back
- Sand things down
Polyfilling is a straightforward job but takes some time as for screw holes you need to polyfill, wait for the polyfiller to thoroughly dry and then fill again. It should be possible to fill in the morning and again in the evening but I needed to wait a day between fills. I also used a lot of filler where the boards abutted each other. There were minor height differences despite being screwed into the floor, however I was able to make these differences much smoother. I believe this improved the appearance of the finished vinyl so well worth the effort.
I wanted to avoid any squeaks of wood on metal so deliberately sized the three ply boards to be 1/4" away from the walls. I don’t want these gaps to show with the vinyl so I used Great Stuff Gaps and Cracks to fill these edges with foam. Controlling the rate of flor in order to get a good finish is difficult. Despite a few mistakes early on I think I got the hang of it and the end result once trimmed back was good. I’m concerned that the frequent vibrations in the back of the van might cause this to dissolve over time but it’s too early to tell. Be patient and give the foam at least as long as the can recommends in order to fully cure. I was eager and tried to cut flush one section early only to quickly abort. For trimming back I used a cheap caulking spatula.
Finally I sanded down the polyfiller and any rough sections on the plywood to ensure a smooth finish for the adhesive and vinyl.
Adhering the vinyl to the plywood subfloor
I used a cheap 1/16" square-notched trowel to spread Roberts 6300 Pressure Sensitive Adhesive to the floor of the van. With some effort you can get very smooth regular grooves. I’ve not used adhesive like this before but I suspect that concentrating on a smooth layer of adhesive really helps improve the finish.
moreystransit managed to glue their vinyl in two halves. Unlike those guys I ended up applying adhesive to the whole floor working from the cab to the rear of the van and then rolling the vinyl from the rear of the van with some assistance. This was a somewhat hairy procedure but by balancing on either wheel arch it is achievable with a RWB Transit. Be careful all during the unroll process that everything is square and well fitting. I chose to do this in the evening when it was cooler (maybe 15-18C) so that the adhesive would start to get sticky faster and curing would be sped up. This was a good decision but had applying the adhesive taken much longer I may have regretted it. I suspect half of my time was spent just figuring out how to use the trowel effectively so if you’re familiar with this it’s definitely a good call.
As soon as the vinyl is down use a rolling pill to iron out any minor air bubbles, etc. that might show up. In my case there were just a few and this step did not take long.
Finishing touches (which are still not complete!)
These are largely broken down into:
- Seal the edges
- Install trim
- Side entry trim (still not complete)
- Rear entry trim (possibly skipping)
- Cab trim
I used GE Silicone II Clear Caulk all the way around the edges where the vinyl meets the wall. I’ve heard silicone caulk is more messy than others but it’s also the most flexible. Since vinyl can expand & contract with temperature changes (which as we all know can be extreme in some of the locations we visit in our vans!) this makes silicone a good choice. I used a caulking tool (really just a piece of plastic with a curve on the end) to give the caulk a good consistent shape and finish which looks great. Again, I was a little impatient to get to caulking when I should have done more prep removing a few small pieces of gap and crack foam from the walls. This is a visible imperfection at the edges but all areas are still well sealed and my ply walls, bed, etc. will fully cover the edges.
Initially I planned (and may still) install either aluminium carpet or step trim at both the rear and side entryway but also where the vinyl floor meets the plastic mat of the cab. To date I’ve only installed the cab trim which looks very smart.
I may forego the rear trim as I found that the vinyl neatly tucks under the plastic step. I discovered this totally by accident so it’s unfortunate than just over an inch at the back is too short to fit neatly underneath. If this continues to annoy me then carpet trim will go down.
The side entry trim is more tricky than I expected due to the right angles. I probably need to borrow a proper saw that can cut the aluminium at the 45 degree angles I require.
I’m writing this post approximately three months after I completed the bulk of the floor (everything except trims). To date the floor has performed extremely well in a few thousand miles of driving. No lumps or bubbles in the vinyl, no issues with the silicone caulk.
I don’t think I would change anything with the plan, however I do wish I’d been a little more patient in waiting for things to cure, and in cleaning up the few small spots from the foam filler.