New lorry floors - how do they do it?

[Ginge Crosby]

As above really. My little lorry has a thick floor, it looks almost like railway sleepers, but i'm worried that it's getting to be time for a new one. There's no obvious signs of rotting or damage, but it's been stood empty all winter, the roof's been leaking a fair bit, and the lorry itself is an L reg (so pretty damn old!). My friend sadly lost a horse not too long ago after she went through the floor of a relatively newly-built lorry, and it's really made me think about the safety of mine.

So what would a new, modern floor comprise of? With the right materials, is it a job that an experienced mechanic (OH) and carpenter (Dad) could do?

 

[MilosDad]

I have just rebuilt a lorry and floors are a vexed question.
You must strip out all the old wood and reveal the steel underneath. There is very little doubt that there will be a lot of rot especially in the areas where the horses' urine collects and also the splash areas from the rear wheels.
With mine the only sound bits were the verticals!!
So you will need a mechanic who can cut steel weld and paint prior to putting a floor down. With regards to floor ply will be lighter than the old wood, you can use marine ply (expensive) or ordinary ply and treat it yourself (cheaper but takes time) As a hint when painting pour paint (or oil) down the inner surfaces of your steel cross members to reduce internal rot.
Hope this helps

 

[Ginge Crosby]

Definitely helps, thanks. Do people put in aluminium floors? Is there a layering system with plywood and aluminium? or if it's just the wood, is it just one layer? so many questions lol!

 

[perfect11s]

Definitely helps, thanks. Do people put in aluminium floors? Is there a layering system with plywood and aluminium? or if it's just the wood, is it just one layer? so many questions lol!

I would have a good crawl underneath like the op said you need to check the metal work, if its sound and the existing floor is basicly sound you could just overlay it with phenol resin ply. NEVER use marine ply or ordanary ply it soon rots and isnt that much cheaper, use 12 mm or thicker if the floor bearers are dogey I would ask a horse box or comercial body builder for a quote, if you need to renew the orignal wood you could use aluminum planks which interlock and are strong and light but not cheap. look up service metals they supply all the stuff like the phenol ply and alluminum sections planks etc, hope this helps

 

[Spottyappy]

I have rhino board laid over my wooden floor,which is sound. My mechanic/ box maintenance man said its safer than marine ply. Cost me £480 last year to do,and have rubber mats laid on top.Box is 7.5t,and takes 2 horses small pony. Needed 4 or 5 boards if my memory serves me right. Would love aluminium floor put in,but not enquired about cost. Imagine the take the bdy off,and put floor under it,but not sure.

 

[perfect11s]

I have rhino board laid over my wooden floor,which is sound. My mechanic/ box maintenance man said its safer than marine ply. Cost me £480 last year to do,and have rubber mats laid on top.Box is 7.5t,and takes 2 horses small pony. Needed 4 or 5 boards if my memory serves me right. Would love aluminium floor put in,but not enquired about cost. Imagine the take the bdy off,and put floor under it,but not sure.

Yes thats the stuff, Rhino is a trade name for phenol ply some firms call it anti slip mesh, (flooring) im glad your guy used it sadly some builders still use marine ply with horific results as it rots from the inside, a friends ramp had been done with it and then matted, a horse nearly went though it with only the rubber mat stopping it going right thru !!! when it was stripped off it just came off in spongy flakes dosent bare thinking about if it had been the actual floor....

 

[PaddyMonty]

My take on this.
Do not just lay new wood over old. It will rot faster.
Phenol board is a good product. Plywood can be used but the problem is there are a hge number of different plywoods. Standard ply is made from softwoods, Marine ply can also be made of softwoods. It is the glue used (water proof) to laminite the layers of wood that makes marine ply different.
If its made of softwood then the wood will still rot pretty quickly.
The number of layers in the plywood also have a significant bearing on the strength. Cheap ply will use 3 layers, decent ply 7 layers or more.
When I replaced the floor in out 7.5t I used 18mm, 7 layer, far eastern hardwood ply. All panels were cut to size and drilled for fitting. The panles were then removed and given several coats of a decent exterior varnish with special attention paid to the edges and screw holes. It is no good just fitting the wood then coating the upper and lower surface and water/urine etc will get in to the edges and screw holes.

If you want to use ali then it has to be the correct 'I' beam type planks. Sheet ali is just not strong enough if using the normally spaced floor supports found on horseboxes. Also note you have to put a barrier between steel and ali or corrosion will result.

 

[Ginge Crosby]

great thanks for all the info, very helpful!