Water Proof Plywood

[Chris C]

I don't own an Airstream. But I dream of owning one someday! Of all the things that can go wrong in a travel trailer, the thing that scares me most about the Airstreams is the comments about "rotten flooring". I can't, for the life of me, understand why Airstream doesn't just install waterproof flooring plywood in the first place. I know it exists because I've got a piece of 3/4" waterproof plywood used in the manufacturing of the wooden decks for boat docks. I have it installed as flooring in a horse containing chute and it's been completely exposed to the weather (sun, rain and snow) now for 28 years with absolutely no deterioration.............none whatsoever! It cost me about 50% more than regular plywood and was worth every single penny of cost. That would end the problem for Airstream owners. I just don't get it. Any thoughts?

[Silver Hawk]

Never seen it. sounds great - do you have any idea where to get it? It would be a god send. Best I could come up with was using West marine epoxy to seal the plywood.

[Wingeezer]

Can't answer your question - maybe one day Airstream will tell us! It is probably the biggest factor that prevents me from buying a new Airstream at this stage of the game.

There are man-made floor materials that I understand are completely impervious to water - but some have suggested they would be cost prohibitive. Could be so, I know that one other trailer company that incorporated such material went bust after just one or two years!

But I have read that Airstream currently uses a grade of plywood that while not being marine grade is "better than your average plywood!"

Not sure if that is correct, or if so, when they began to use it, maybe someone can comment.


Brian

[TinTin]

Could be a couple of factors involved.

Some treated woods are not approved for interior use since they can off-gas nasty preservatives. Is the plywood that you've used 'treated' or simply marine plywood?

Another factor may be the added cost ... which is probably minimal in the whole scheme of things.

[shannon]

We went back with marine grade, and painted edges to add to preservation.

[Chris C]

Originally Posted by TinTin

Could be a couple of factors involved.

Some treated woods are not approved for interior use since they can off-gas nasty preservatives. Is the plywood that you've used 'treated' or simply marine plywood?

Another factor may be the added cost ... which is probably minimal in the whole scheme of things.

I have no idea the "grade" of plywood. I know it's impregnated with "something"...........could be a resin, I don't know. I just know I've been amazed through all these years to see that darned piece of plywood not showing any signs of weathering. I'm sure it cost me a pretty penny for the small amount I bought when building the chute. But the fact it's lasted this long has made it worth every penny, for sure. I know it's heavier than a similar piece of plywood, so that may also be a factor.

[rostam]

Or they could build Aluminium subfloors (like some 70's Argosy trailers) and eliminate the problem. Its unbelievable that in this day and age such a problem exists in the first place (and for such an expensive product). I have been looking for an older Airstream/Argosy for a while, but the floor rot scares me too. I have expanded the search to Avions as they seem to have a better design (seems unlike Airstream plywood is not sandwiched between chassis and frame, so floor rot would be less of a headache).

[Chris C]

Originally Posted by Silver Hawk

Never seen it. sounds great - do you have any idea where to get it? It would be a god send. Best I could come up with was using West marine epoxy to seal the plywood.

Can't remember the name of the company or the actual name of the plywood, but I purchased it from a company that made floating docks for the State of Oklahoma back in the 80's. If I were looking for it today, I'd research the floating dock manufacturers.

[InsideOut]

"Waterproof Plywood" is the same as "Marine Grade Plywood" - it's what we used when we rebuilt our trailer several years ago. It was about twice as expensive as regular "exterior Grade" plywood - definitely money well spent IMO. It's typically found at specialty lumber yards - not the orange or blue box stores.

Plywood Grades

Shari

[Isuzusweet]

Yes it comes down to cost, "The almighty dollar."

Sadly the cost of switching to a composite like Coosa in the manufacturing stage would be minimal for the consumer. Would every Airstream customer pay $1,000.00 more for a subfloor that was impervious to water, bugs, rodents, mildew, fungus, rot, dry rot and was 40 - 45% lighter than the comparable plywood Airstream now installs in its trailers?

You tell me? All I know is, if presented with buying two used Airstreams one with a Coosa floor and one without, I know which one I would buy.

Coosa Composites, LLC - Manufacture of high-density, fiberglass-reinforced polyurethane foam panels

Cheers
Tony

PS I used the Bluewater 20 for my project as the board needed only to span 14" at the most. As a test I placed a 5" strip across two saw horses and stood on it. At 250+ lbs I bent the piece of Coosa but it didn't break......I then started bouncing up and down. It did eventually crack but didn't break.

[Chris C]

Believe me, Sheri, this isn't Marine Grade plywood. I know the difference. This has been impregnated with some resin like Phenolic or something. This and Marine Grade aren't even in the same league. I've used Marine Grade in a lot of boat building projects.

[Silverflames]

Well if you can figure out the name of the product let us know. Sounds very interesting. Like others we used Marine grade plywood and then coated it in resin. I think is AS took the time to do this on the edges and 12" of the outside perimeter the floors would have held up a lot better. Also some of the 60s and 70s models have a design flaw in the rear end that causes water to be directed to the plywood.

Overall, even with rotten spots, there are few other trailers that last so long. My AS is older than me! I feel soft around the edges some days..


Sent from my iPhone using Airstream Forums

[Chris C]

It's been a lot of years, and the old memory "ain't what it used to be", but I'll try and locate the man I bought it from. He used to make floating docks for the State of Oklahoma. He retired 15 or so years ago, but I'll see what I can find.

[AWCHIEF]

OP, I asked the same basic question at the factory a few weeks ago and just got blank stares. I suppose it is one of those subjects that they have been instructed to not discuss.

[Chris C]

That's a shame, Michael. They ought to be addressing something so vital.

Chris

[dkottum]

It can't rot if it's dry. That is the remaining choice we have as owners. For less than $50 you can get a moisture detection meter and probe the perimeter of the plywood subfloor to ensure is not wet, a quarterly inspection should do it depending on climate. There are also pressure leaks tests valuable to use as you see fit.

If it is leaking, you would want to know and seal the leak regardless of floor material as unhealthy conditions such as mold, and structural corrosion will result soon enough.

The products I'm aware of used to waterproof plywood is not something I would want spread throughout the inside of the house we live in. Plywood as used by Airstream is considered safe and has been used for generations.

[AWCHIEF]

Marine plywood varies greatly between US and Lloyds standard. U.S. marine ply does not use a high level of water proof glue, allows voids between layers and filled voids in the much thinner exterior ply. Lloyds uses a higher quality glue, zero interior and exterior filled voids and equal thickness ply. Airstream only uses US marine ply in their floors. I build wood lap built boats and only us plywood that is fully Lloyds certified. Even then I still coat all ply surfaces with a thin layer of fiberglass cloth or resin. It makes for a fully waterproof surface that is resistant to bangs and dings.

During my recent visit to the factory they were leak testing a new trailer. The rear access hatch was masked off with plastic sheeting and lots of wide blue tape. This struck me as a bit strange as this an area that is oft reported as having leaking issues in some trailers. I attempted to ask a question about this and was basically ignored. Again this seems to be one of those areas that employees have been instructed to not answer questions about.

[Chris C]

Hmmmmm! My little Casita is looking better by the post!

[Dingo Girl]

We have a local military supplier here and they used at one time a very, very heavy type of plywood that had coating of fiberglass for the top and bottom ply and was also impregnated with a resin as well.
I had a piece of this stuff outdoors for many many years. It never rotted.
They used it for decking on military ramps and carriers.
I can see where the weight of this stuff would be prohibitive for use as floor material in my Caravel. The floor would weigh as much as the whole trailer.

[Chris C]

Dingo Girl, that sounds a lot like the material I have on my horse chute. Yes, the weight might well be a rather negative factor.