wood choice for van floor

[brianhabby]

Hi there,

My latest project is converting an old bus into a campervan/motorhome, something that is certainly not a short term project. The original floor had to come up because it was badly damaged and I plan to replace it with ½"ply but I need advice for the subfloor.
The picture shows the van as it is now with the chassis exposed and the wheel arch. You'll notice that the top of the wheel arch is several inches above the chassis level so I need to put some battens on the chassis in order to get a nice level floor.

What wood should I use bearing in mind that it needs to be strong yet light?

Any ideas would be most welcome

regards

Brian

 

[9fingers]

If you want to use battens then pressure treated softwood should be appropriate.

One thought I had was to arrange for the internal fittings (cupboards, seats etc) to be placed over the wheel arches so that the floor could sit directly on the chassis bearers this saving all the battens.

Bob

 

[brianhabby]

One thought I had was to arrange for the internal fittings (cupboards, seats etc) to be placed over the wheel arches so that the floor could sit directly on the chassis bearers this saving all the battens.
Bob

I had though about that but it wouldn't really work for the layout we want in the van, plus the tops of the wheel arches are a right mess, full of holes so we want to cover all that up all well.

BTW, does anyone know where I can get hold of ply that has insulation bonded to one side or some kind of sandwich construction, I don't like cold tootsies in the winter!

regards

Brian

 

[chippie244]

Use kingspan/celotex/thermal board for the insulation.

 

[spadge]

Can't help with your query but this site may be able to:-

http://www.sbmcc.co.uk/

 

[StevieB]

Why do you want the insulation bonded to the ply? Kingspan is phenominally expensive (as I just found out when getting a quote to insulate a loft) but a piece of polystyrene is much cheaper - jabbalite or similar. This may also solve your battening problem - ply sub floor over the base as it is now, layer of 2" or 4" polystyrene sheet and a second layer of ply on the top. Would this be enough to raise the floor over the wheelarch?

Steve.

 

[Shultzy]

Brian I'd go with StevieB's idea, and if the lower ply is exposed to the underneath plenty of underseal to keep it dry.

 

[Sean the amateur]

Brian,

In Denmark and Germany you can buy a brown plywood which looks as though it has been impregnated with wax under pressure. They use it among other things to make floors for utility trailers. Id it is good enough for trailers it should be good enough for a van.

Talk to a trailer in the UK. eg Ifor Williams in Wales

Sean

 

[brianhabby]

I'm beginning to think that insulation bonded to the ply would be too expensive. I would still like to get hold of a lightweight ply if possible to save weight on the van, but failing that I'll just use ordinary ply.

When we used polystyrene on a previous van, albeit not in a floor sandwich but in the side panels, there were problems with squeaking. Would a layer of ply with a layer of polystyrene and then another layer of ply on top be good enough? What about movement and squeaks?

Another idea I had was to put a thin (¼") piece of ply straight onto the existing metal struts, build up my framework to the top of the wheel boxes in relatively small sections, and then a piece of ½" ply on top of that, and put expanding foam in the cavity. Trylon.co.uk sell polyurethane foam that comes as two chemicals that you mix together. A 2Ltr pack is only £18.74. this is a lot cheaper than those aerosols you buy in DIY places and you can mix up exactly the right amount for your needs. I think the 2Ltr pack would be more than enough for my needs.

regards

Brian

 

[woodbloke]

Brian - if you go for the 6mm ply I'd use marine grade, 'specially if there's any chance of prolonged contact with water, not too expensive if you shop around - Rob

 

[engineer one]

brian can i suggest you go back to the drawing board since you are at the most important stage now.

1/ i assume you are going to clean up and paint the chassis members to remove rust, and then make them safer.

2/ why build up the floor between the wheel arches. rather why not take advantage of the space there?? they would certainly allow plenty of storage which you could access from either inside or out from what i can see in the photograph the lower body seems to go down quite a long way.
so what i am suggesting is making storage boxes which bring the side up to the height of the wheel arches.

3/ have you thought about the bed, the seating area, and the walk space.

4/ next thought have you considered how you would mount the ply. if it is too tight, then you will get a fair amount of noise transfer as the chassis moves.

5/ have you thought about access from above for various things under the chassis, like suspension parts, springs, the diff, and even the gear box.
what about hydraulic pipe runs and the water and heating system. these too will determine how you floor the vehicle.

6/ finally why are you that worried about weight, frankly, i cannot see that anything you are intending to do is going to add enough weight to make a substantive difference to the vehicles performance, or fuel economy.

7/ are you going to fit a fridge, cooker, toilet basin and shower facilities, then if so, check about fitting these before putting a sub floor, because you might well be able to fit them underneath or in the case of the loo, you need the water tanks etc.

layout your need before thinking about laying a floor.

paul :wink:

 

[cambournepete]

My Brenderup trailer has a bas emade of 18mm phenol-coated plywood.
I was a little concerned it wasn't steel, but after 7 years it's only slightly worn and good for many years yet.

Try to find a trailer supplier or manufacturer in your area and they probably be able to sell you the plywood.

 

[brianhabby]

Hi there,

Woodbloke,

Yes I think marine ply would be a good choice, but how do I know that I am getting proper marine ply though and not being fobbed off with standard stuff?


Paul,

thanks for your comments, you have made some good points although we had already though about most of them.

1) Yes I am going to clean up the chassis and paint it, I did take it for steam cleaning but was quite disappointed with the result. There were lots of parts that were simply missed, and that was after I complained and gave them a second chance at it. The boss of the firm later admitted that their steam machine had a tool that was too long to reach everywhere properly. I told him he shouldn't have taken on the job if he didn't have the tools to do it properly, or at least be honest with me and tell me what he was and wasn't able to do.

Looks like I'll have to do the rest of the clean up manually now, still it was always meant to be a labour of love

2) There are steel members sitting on top of the chassis and the floor will fit on top of these. See photo below. This will give us lots of storage space under the floor for water and waste tanks etc.

3) Oh yes - we have thought about layout, in fact SWMBO thinks about nothing else these days.

4) You're right of course, if the ply is too tight it will present all sorts of problems. The old floor was slightly smaller than the space available and this was filled with a mastic both at the edges and underneath where it sat on the steel members (you can see some of it is still visible on the pics). These mastics are available from specialists suppliers and I plan to use something along these lines. This should stop any movement because this stuff never dries.

5) Access shouldn't be a problem, all the running gear will be just as accessible as on any normal van. As for access to the tanks, I will need to put some kind of trap doors in the floor to cater for this.

6) Fuel economy and performance are actually secondary the the legal requirements for these vehicles. I need to make sure that the final weight of the van is within the permitted maximum and the lighter I can make all the fittings the more leeway for packing personal belongings when we go away.

7) Fridge, cooker, toilet, sink units all have to be fitted and these all have an impact on weight of course.


cambournepete,

Yes I might have a word with a trailer manufacturer - a good idea

I really must sort out a web page with more pics on so people can get a better idea of what we are doing. I'll try to do that soon and post the address on here for anyone interested

This is certainly an interesting project and the more I think about it the more keen I am to get on with it - in fact I've booked a week's holiday from work next week just to work on the van.

regards

Brian