Crappy Plywood

[Jack]

I know the early particle board was no good for damp conditions. Neither is indoor plywood. The OSB used for roofing is extremely durable. I don't think this stuff is special either. The Cat houses I made were made with container boxes used to ship clothes. It was in the early 90's that I saw it used on cabins for siding, unfinished. I asked the guy that built one, who was a carpenter by profession, how he expected it to hold up outside, as I was thinking like some of you that it was junk, and would fall apart when wet. Well, it never did, and neither did the cat houses I built.

When krw said, and I quote:

"OSB is often used on walls, with CDX corners, but anyone who uses it on roofs should be taken out and shot."

Well, it shows he is clueless, and someone besides the builders using it should be "taken out and shot". Virtually ALL roofs are sheathed with this stuff around here, and I suspect the rest of the country is the same.

[Sonny]

OT, but your pic reminded me of this song.

Sonny

[Leon]

Yes, "the cheapest that I can buy at my supplier" is very often better than domestic.

[Leon]

OR if you use water based primers and paints on it.

[krw]

Right. It might take some rain but it doesn't hold nails for a crap.

[Martin Eastburn]

Maybe 25 years ago or so in the San Fernando valley - south San Jose there was a large builder that was caught with his pants down.

80 some houses lost their roofs because the OSB was glued up with water based glue. It took several storms for the OSB to turn into globs.

He had to go in, clean up the mess and replace the roofs and interior if not protected from rain in time.

I think what it was mill mistake. If you know the plants - OSB is made in an OSB plant. Ply in a ply plant.

That is the way it is done out here. Chip trucks sometimes come from one mill to the other - as scrap is valuable in OSB more than heat.

A judge was required to get him into action.

Mart> >> Water based glue used on interior grades will give up if it is

[Jack]

That's wrong as well. CDX may hold a *hair* better, if you are not nailing into a void, but it is a negligible difference in roofing. My Shed that I built 26 years ago has OSB and shingle roof and it is in perfect shape, and not one shingle has come loose. So just like 1x's hold better than ply, it is negligible.

You can see that my shed and it's OSB roof is still holding up well after 26 years of Pgh. weather:

When I was a kid, all homes used 1x12 sheathing (#4 pine) for roofing. Ply was 'cheap ass garbage' and anyone 'using it on roofs should be shot' Turns out 1x _is_ better, but ply is good enough. OSB is/was in the same place and nobody needs to be shot.

[Jack]

Yes, that would be a disaster. If indoor plywood gets wet, it explodes as well. When I was young you had to specify indoor or outdoor for plywood. Not sure the indoor stuff is that common today, I think all the glues are fairly water resistant, but I'm just guessing, I rarely buy plywood or build much indoors or outdoors any more so it's just a feeling I get.

[woodchucker]

Well my home was built in 87, and the osb rotted away on the sheathing. I had to replace sections that I was working on as it would not hold a nail.

It all turned black... was not water logged, was just rotted .. I think the glue gave really.

A bunch of you told me how much better OsB is today. I'm not sure yet. But I still harbor lots of ill feelings about it. I know that if I ever strip off the aluminum siding, I'll probably have to replace all the sheathing.

[krw]

Bullshit. This is also why plywood, or corner bracing, is needed where OSB is used for sheathing. My VT house had OSB sheathing. I could pull a siding nail with my bare hands. I had to make sure to hit the studs or the siding would just fall off.

1- It's a frappin' shed. 2- Anecdote evidence.

OSB isn't.

[Martin Eastburn]

I've seen a show on Alaska building in the outback and they got a pallet that was brought in and put under a tarp. When they went to it - it was coming apart. Either the buyer bought cheap or didn't know and the seller is likely just taking money.(bad on him also).

Mart> >> Maybe 25 years ago or so in the San Fernando valley - south San Jose

[Jack]

Perhaps you got the same stuff Martin was talking about where 80 homes were built with the wrong glue base? If my cat houses and some cabins sided with this stuff, and exposed unfinished to the elements for 20+ years is still in good shape, not to mention millions of contractors have been using it for many years with no problems, it would seem odd that your stuff would rot with no exposure to water or the elements.

Not telling you what to use, but OSB is commonly used today in the building industry. You of course can use 1x12 sheathing like they did in the old days, or use plywood like they did before OSB. Hopefully, no one will shoot you for whatever you choose:-)

[Jack]

Bullshit!

Yeahbutt I never told the OSB what it was being used on.

Experience = evidence. Common usage = evidence. You = bullshit!

it is!

[krw]

Ah, so you were there. Why the *F_CK* didn't you help!

Size matters.

You can keep repeating bullshit but that doesn't make it smell any better.

You can continue to say that but you can also continue to be *wrong*. there is a reason it's not allowed as corner sheathing in many areas. Plywood or diagonal bracing is required.

[DerbyDad03]

I'm not agreeing or disagreeing, but this (admittedly 10 year old) article makes no distinction between plywood and OSB when discussing Wall Bracing and the IRC.

This one discusses using OSB to corner brace a foam sheathed wall: "It?s possible to brace a wall with just a few sheets of plywood or OSB. A small house may require only two sheets of OSB per wall, usually located at the corners."

-sheathed-walls

Habitat For Humanity in Denver is fine with OSB for sheathing, but not for barricades across openings.

I'm sure some local codes are stricter, and there may even an updated IRC since 2006, but it seems (at least to me) that OSB is an acceptable produc t for bracing.

As always, I'm willing to be proven wrong as I learn. ;-)

[-MIKE-]

How dare you let facts get in the way of a good argument.

[Swingman]

Ditto ... and proving there are many grades, as well as valid uses, of "oriented strand board" that many not in the construction trade are apparently unaware.

IIRC, you used AdvanTech on your shop floor? Happy with it?

[-MIKE-]

Extremely. Of course, as you point out, it is a far cry from the "oriented strand board" these guys are scratching each others' eyes out over. :-)

Nonetheless, it's a shame that people who have a bad experience with a product at the inception of its use go on the rest of their lives with a deep seated prejudice towards it and allow that bias to color their opinions of just about every other "newfangled" technology that comes along after.

[DerbyDad03]

e:

foam-sheathed-walls

I apologize for interrupting.

Carry on...

[woodchucker]

Around here in my area of NJ Pittstown, NJ central western .. many of the houses being built or expaned seem to be wrapped in ply , I see a lot less OSB.. There still is some OSB, but I have noticed the last few years ply is making a comeback.

Same with commercial small buildings.

Not sure why, just an observation.. There is a lot less building going on then b4 2009, but its still noticeable that ply has comeback.