Teardrops n Tiny Travel Trailers

15mm luan? Do you mean 5mm?

OSB expands and loses structural integrity when exposed to water, you would be relying on your skin being perfect, any flaw would be a gigantic problem. High quality plywood would be a much better choice.

I've seen it used. It doesn't have very good holding strength for the screws that you drive into it. And it can be wicked if it gets wet.

Mike..

OSB does not weather well, even when painted.

Some here have tried it, and after a few years it looks pretty rough...though theirs has been exposed.
In a sandwich situation, it "might" work out, but why take the chance?

Plywood is a much better choice.

Rob

I wouldn't use osb for anything. my buddy who has worked construction his whole life calls it particle board, when I correct him he says it's the same thing. when people say osb is better than plywood, I ask them if they make marine osb. end of conversation. highdesertranger

I just finished rebuilding my shed. The guy sheathed it with OSB and did a horrible job at that. Any place the painted stuff was exposed to water it rotted. In central Idaho, about the only way to rot wood is to lay it on the ground. Except OSB.

There is a brand of OSB that is made with superior adhesives; Advantech from Huber Engineered Woods. It is great stuff. It does not suffer from the edge swell as much as standard OSB. It comes in 5 thicknesses from 19/32 to 1 1/8" . I prefer it to plywood in home construction.

Edge swell is more pronounced with std OSB than with plywood, but overall plywood absorbs more water than OSB. OSB has some advantages over some plywoods. IE standard OSB is usually a more consistent product than standard construction CD grade plywood; there are no layers where 2 knots may appear in adjacent layers for example. However if we use higher grades of plywoods, especially plywoods like Marine grade, no OSB will likely come close in quality. The whole quality thing revolves around the adhesives used to adhere the strands or the plies. And OSB is meant to be a substarate; it was never meant to be painted as a finished visible component. And it looks like heck when used like that.

BTW, OSB is a very different material from the old waferboards of yesteryear or the particleboards of today. FYI, true OSB was first manufactured in 1991, waferboard came out in 1963, plywood in 1905 but the first plywood with waterproof adhesives came in the 30's with great improvements in the 50's and 60's.

For the curious here is alink to a very good comparison with the orientation slanted to the construction trades. The author is a recognized expert in the construction industry.

Travel trailers are most likely closer to boats than to houses though, when it comes to materials and their suitability. IMO.

In six months or a year, do you want to say "I wish I had paid for the better plywwod" as you tear your hard work apart?

Why chance it? The number one problem with boats and trailers is WATER intrusion. And regardless what you do, or quality of build, water finds a way to make you look like an idiot. Don't skimp on quality materials for you build. Your cost savings are in your sweat equity.

like i said, do they make marine osb. the answer is no. but of course you can use it for whatever you want. highdesertranger

Eggbert was 7/16 osb

Chubby is 5/8 osb sub siding

Rip van winkle is 7/16 zip wall a fiberglass faced osb protected by FRP

The chuckwagon is 7/16 zip wall also with the same FRP outer skin.



They are all still viable after 7+ years.

Hell the caboose is 7/16 zip wall covered with only 2 coats of tractor enamel paint It has been in the weather 26 months and shows no sign of any distress.



Some of us poor folk just cant afford the 72 layer oak faced marine plywood at a gazillion dollars a sheet.