Plywood or OSB?

[Falcon67]

I have pics but can't find them right now - behind us, an older lady's son built her a "storage shed". "sonny" is a roofer and after seeing his shed work, I wouldn't let him roof my dog house. Anyway, this "shed" is about an 8x8x8 box of OSB with a mildly sloped single pitch roof. The high side of the slope and the door faces west, which is the normal direction the storms come in. There is maybe one layer of tar paper on the "roof" and a couple of pieces of tin. Looks more like a slap dash chicken house, really. There is no finish or siding, it's just OSB out of the back of the truck nailed to some studs. It's been there over a year in all kinds of weather including snow. The OSB surface has a bit of a "fuzz" to it, but you have to get close to it to see that. Same as the attic flooring in my shop that was exposed to weather for about 4 months that had water puddling on it. Other than that, the "shed" shows no real deterioration or damage from exposure.

My personal exposure experiment with OSB was a 4x6 piece of 1/4" OSB that covered part of a west facing exterior door opening on my old garage. It was there to keep the dogs in the yard. It was there for 9 years with no finish. It cupped some, and was pretty discolored but never delaminated or fell apart. Had to cut it up with a saw to get rid of it when I finally fixed that part of the garage.

 

[Rust]

You've been out of the business for a LONG time if engineered joists are something new to you.

New? Nah...Dont recall saying that... lol

Just would'nt pony up half a million for a house built with them.

 

[madstat]

This piece of 1/2" osb has been sitting in a junk pile in my back yard here in Michigan since last June. We just had a pretty decent rain today, regardless it was out here all winter uncovered. Now if only I had a pice of cdx next to it we could compare. My guess is that the cdx would be half way to a pretzel by now... not that the osb looks good either. You guys be the judge. I think, when installed correctly with proper underlayment both products do the job that they are supposed to do.

A really interesting question to me is why here in N. America do we build our homes out of such fragile material. Masonry based buildings in Europe and indeed all over the world last hundreds of hundreds of years with little concern for "sealing cut edges" and the like. I guess its just the way we roll.

 

[NUTTSGT]

I honestly cannot think of ONE benefit real lumber has over them.

*Stronger
*Lighter
*Straighter
*will never twist
and CHEAPER

I can guarantee that traditional lumber will survive a fire longer than the OSB engineered joists.

Slightly off subject, as I have been taught, the fire service uses a 10 minute window for standard roof trusses. Ten minutes from the time they are exposed to fire, they will start to fail due to the nailing plates.

 

[NUTTSGT]

BTW, I'm not saying that I would never use them, just throwing that information out.

 

[Big Bad Dad]

So...What is this OSB sealant?
I've been in construction for 25 years and I've never seen it.
Educate me.

X2 for me