On 11/10/2016 9:47 AM, Jack wrote:
On 11/9/2016 12:57 PM, krw wrote:

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."

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

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:

http://jbstein.com/Flick/ShedN0163e.jpg
http://jbstein.com/Flick/ShedP1060140Rc.jpg
http://jbstein.com/Flick/ShedP1030201c2.jpg
http://jbstein.com/Flick/ShedP1030192.JPG

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.


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.


--
Jeff