Travel Trailer flooring

[theoldwizard1]

I don't want to use any kind of wood based flooring because it will rot if it gets wet.

Honeycomb polypropylene or extruded polystyrene (Owens Corning Foamular 400). In both cases, I know I will probably have to use 1" thick (or doubled 1/2" thick) sheets. I would like to use 1.5" - 2" steel channel for "joists", 16 O.C. 8' span.

Alternative suggestions ?

 

[Firebrick43]

PP Honeycomb and XPS are core materials, and need to be heavily fiber glassed in order to use as flooring. XPS is not a good core for structural items and you can only use epoxy resin with it as polystyrene in polyester resin will melt it

PP honeycomb, AKA nida core wouldn't be my choice for floors, it doesn't hold up to point loads very well, has no screw holding ability. Takes a lot of extra work to core out an area and fill with thickened resin before actually drilling the thru hole so the core isn't crushed. Probably would want 3 layers of 1708 biax and 1.5oz chop strand mat on top and 2 on bottom. Its use is more for walls, partitions, roofs ect.

Coosa board is a better choice than either for floors. Coosa bluewater 20 would be fine for a floor. Still needs 2 layers of 1708 and a layer of 1.5 chop strand mat on top and 2 layers of 1708 on bottom.

 

[mm08822]

What types of loads - weight and type of point loading. Flat boxes or logs are different than small equipment feet or corners of metal frames digging in. Will the loads be pushed on and dragged off?
Size of trailer bed, # wheels, weight rating...............

 

[kbeefy]

Flooring is so diverse. Then make it move and you have a whole nother set of parameters to deal with.

My trailer is just painted plywood with some texture added for grip. Probably not something you'd want.

In my van/rv, I didn't want laminate or smooth surface because things slide around so much. I did however want something water repellent and hopefully sealed.

I haven't done it yet, but I am very interested in boat floor/deck covering. There is a product similar to neoprene that is durable and designed to be walked on.

 

[PCustoms]

Nevermind

 

[Firebrick43]

What types of loads - weight and type of point loading. Flat boxes or logs are different than small equipment feet or corners of metal frames digging in. Will the loads be pushed on and dragged off?
Size of trailer bed, # wheels, weight rating...............

By the title he is talking about an RV not a cargo or equipment trailer.

 

[duneslider]

I totally understand the desire to not have wood that would rot but this seems a bit extreme. I am assuming you are repairing a damaged trailer? If you were building a new trailer from the ground up something like the coosa board would be sweet but man it is expensive...

I repaired my previous trailer's floor, so I understand the amount of work it takes to make it happen. I used pressure treated plywood and I can guarantee it will outlast the trailer. I also fixed the water leaks that caused the problem in the first place.

Just another note, while I know the foam sandwich floors are a problem waiting to happen, the half my trailer that was just pressure treated plywood, the floor was significantly colder than the other half. I ended up going back a year or two later and adding some foam board to the bottom of that half of the trailer everywhere I had access to try and help. We do use the trailer a fair bit in the late fall, late winter, and early spring so the cold floor was very noticeable.

 

[theoldwizard1]

I repaired my previous trailer's floor, so I understand the amount of work it takes to make it happen. I used pressure treated plywood and I can guarantee it will outlast the trailer.

That looks like the only "cost effective" solution !

 

[duneslider]

That looks like the only "cost effective" solution !

I used 3/4 pressure treated ply and it worked great. It felt incredibly solid and unless you were using it as a boat or something I think the pressure treated ply would last forever. I primed mine both sides with kilz (just cause I had it). I put some of that stick on flooring on it when I was done and I wouldn't recommend that stuff, it didn't hold up well. Going with a sheet vinyl would have been better.

 

[Firebrick43]

Pressure treated ply was used for years in the small boat/pontoon boat industry to prevent warranty claims of rotted floors and was somewhat successful in that 10-15 years before they rot.

However treated ply or lumber of most formulations are corrosive and owners sometimes find significant damage to the framing members when the floors eventually do rot out. If you do go down that line it would be wise to use SS screws and isolation tape on the crossmembers.

Another solution is ACX ply coated in a wet coat of polyester resin. As the resin soaks in and begins to tack up put another coat on and wet out a single layer of 6 oz glass top and bottom.

If the ACX has some deep flaws on the backside fill them with polyester body filler and sand before applying the resin and fiberglass

 

[Hank11]

Coosa board would be excellent, if pricey. For your use, two layers of 10oz cloth on both sides and you are ready to go. What will the trailer be used for? Do you need to fasten things to the floor? Just people walking around loads?

 

[theoldwizard1]

If the ACX has some deep flaws on the backside fill them with polyester body filler and sand before applying the resin and fiberglass

One thing I dislike about modern plywood (with some exceptions) is that the inner layers are grade "C". That means they have voids.

I would use BCX. "A" = no voids, very small knots. "B" = no voids, large knots are plugged.

 

[theoldwizard1]

However treated ply or lumber of most formulations are corrosive and owners sometimes find significant damage to the framing members when the floors eventually do rot out.

That is a big concern ! **IF** I build this, I want a life expectancy of >20 years !

I am leaning toward honeycomb and 'glass.

Another solution is ACX ply coated in a wet coat of polyester resin. As the resin soaks in and begins to tack up put another coat on and wet out a single layer of 6 oz glass top and bottom.

I know this is the "right answer", but I wanted to avoid the work/expense of 2 sided glass !

 

[theoldwizard1]

Coosa board would be excellent, if pricey. For your use, two layers of 10oz cloth on both sides and you are ready to go. What will the trailer be used for? Do you need to fasten things to the floor? Just people walking around loads?

Travel trailer. Cabinets and people loads, except for the water tank which will be mounted inside (to prevent freezing). I will put extra bracing under it.

 

[Firebrick43]

I know this is the "right answer", but I wanted to avoid the work/expense of 2 sided glass !

Yea, the other solutions require more work/expense/layers of glass to have the same strength and point loads that a decent ply has skinned with one. Even coosa board needs one layer on each side of not two on top and it’s very expensive.

 

[Hank11]

I think you could use 3/4 plywood and put one layer of glass on the outside (and the edges). West Systems epoxy becomes a water proof barrier with one layer of 6 oz. cloth full of resin. (I’d go 10 oz.) If the bottom is not exposed to rock damage and such, you could use a single layer and then paint it both sides. I would be very surprised that it didn’t last your 20 year period. Paint both sides and edges.

How many sheets do you need?

Decent quality 3/4 B/C is maybe $75.00 a sheet. Available most everywhere.

3/4 Coosa is around $300.00 per 4x8 and will never rot. Still needs glassing though. If not available locally, shipping will kill you. Lightest option I propose.

A gallon kit of West System epoxy is around $150.00 these days.

You might also think about Advantec. Heavy but durable. They make more grades these days that are extra water resistant.

 

[theoldwizard1]

3/4 Coosa is around $300.00 per 4x8 and will never rot. Still needs glassing though. If not available locally, shipping will kill you. Lightest option I propose.

Coosa 3/4" x 4' x 8' Nautical 15 is over $300.

Coosa 3/4" x 4' x 8' Bluewater 20 is over $350

Coosa 3/4" x 4' x 8' Bluewater 26 is over $380

 

[Hank11]

Coosa 3/4" x 4' x 8' Nautical 15 is over $300.

Coosa 3/4" x 4' x 8' Bluewater 20 is over $350

Coosa 3/4" x 4' x 8' Bluewater 26 is over $380

OK, how many sheets do you need? What’s the budget? Check around for better pricing.
And if you want more help, what supports your floor?

 

[az45]

I just did this dance in a Sprinter; there are lots of ways to do it. I started with 3/4 Birch from Home Depot for the floor, and once I got it cut and installed, it started delaminating. I pulled it out and went with Blatic Birch, which was more plys and glued consistently all the way through. You could probably go 1/2" Baltic Birch on top of a flat plywood floor, but the van has ribs. The floor covering is of a higher quality TPO Coin Flooring, because of it's chemical resistance. I'm not sure plank-style hard flooring wouldn't be more durable if you're dragging stuff across it, it would also allow you to replace a single damaged piece.

I figured out why it's so expensive to pay to have this done, it was way more work than I anticipated.