OT Plywood question

[woodman]

Perhaps when NASA selects OSB for their next space shuttle?

Yeah, maybe we could get back to the moon again with the power of OSB!

[keehah]

Nice thread. Move to Japan? I used to millwright and the planed 2x4's (and wider) were of course much smaller, except for the 'metric' sized wood being exported to Japan that was almost a full dried and planed 2x4 inches.

Also noticed a few years ago that all the 1/2 drywall sold in my area became the equivalent of whipped butter when previously it was solid. The material dents and breaks easily and when I suggested to the sales people it probably offers a lot less fire resistance, they said that is what 5/8 is for, like 1/2" applications never need be concerned about fire.

[midnight rambler]

WWI (phase deuce) PT boats were made of plywood. Wonder what the equivalent made of OSB would look like.

That was a sort of (marine) plywood not made anymore.

[midnight rambler]

OSB relies on compression of the fibers to form it's shape. Compressed wood is more likely to expand when wet. Plywood is compressed too, mainly to bond the glues, but not much beyond it's original dimension.

Based on my own observations manufacturers of sheet goods have steadily been improving their processes especially with respect to their glues. I’ve seen CDX (which is of course exterior grade and supposedly resistant to moisture) that had fully delaminated at about 25 years in place (installed in late ‘60s and involved 100% failure of ~4,000 s.f.). It should not have failed like that in that particular situation - we expected to see a nominal amount of failure not a full 100%.

[hoarder]

Based on my own observations manufacturers of sheet goods have steadily been improving their processes especially with respect to their glues. I’ve seen CDX (which is of course exterior grade and supposedly resistant to moisture) that had fully delaminated at about 25 years in place (installed in late ‘60s and involved 100% failure of ~4,000 s.f.). It should not have failed like that in that particular situation - we expected to see a nominal amount of failure not a full 100%.

My observation is that the manufacturers have been steadily improving their processes to enhance quarterly profits.

[midnight rambler]

My observation is that the manufacturers have been steadily improving their processes to enhance quarterly profits.

Of course there's that. Duh.

When was the last time you were actively involved in construction? (DIY projects don't count)

[hoarder]

Of course there's that. Duh.

When was the last time you were actively involved in construction? (DIY projects don't count)

I just finished building another house this year. I had them sheath the inside of my insulated 1600 square foot garage with 1/2" CDX. I was very disappointed with the quality of the plywood. APA standards must have dropped considerably. It looked like "shop grade" plywood.

[woodman]

I just finished building another house this year. I had them sheath the inside of my insulated 1600 square foot garage with 1/2" CDX. I was very disappointed with the quality of the plywood. APA standards must have dropped considerably. It looked like "shop grade" plywood.

This is true. I've noticed a drop in plywood quality over the last 7 years. I have been retired since last year but still do odd jobs. The actual size of the sheets has been off for the last 4 years at least. I would make a big difference when a sheet was an eighth inch smaller, say 47 7/8" instead of 48" when lining up plywood on a subfloor. The thickness can vary quite a bit also. Much of the 15/32 was often more like 3/8 and we would try to use it by a wall, under the bleachers, etc. This product was coming in big orders, often over a thousand sheets from Home Depot. We figured they were having a hard time getting good help, large employee turnover or something.

[Cebu_4_2]

This is true. I've noticed a drop in plywood quality over the last 7 years. I have been retired since last year but still do odd jobs. The actual size of the sheets has been off for the last 4 years at least. I would make a big difference when a sheet was an eighth inch smaller, say 47 7/8" instead of 48" when lining up plywood on a subfloor. The thickness can vary quite a bit also. Much of the 15/32 was often more like 3/8 and we would try to use it by a wall, under the bleachers, etc. This product was coming in big orders, often over a thousand sheets from Home Depot. We figured they were having a hard time getting good help, large employee turnover or something.

Funny shit reading the reviews on about everything I ordered. The flooring OSB requires 1/8 spacing for expansion and contraction. WTF I'm not building a fucking boat! Might be the waxy shit the use to make it? I don't know. The shit's out side spaced to degass right now.

Pulled the rest of the deck off. Wow. They had some sort of water protection sheet that did not work at all, total fail. I wish I could get pics here cause you would love it. The rot is beyond rot, No Idea how I am going to get a new sill plate in here, and 12 foot long ain't gonna do the job lol. More likely I need another 4 foot to finish this area.. Going to beat up my phone tomorrow cause my camera died also, this needs to be pictured for sure.

[woodman]

Funny shit reading the reviews on about everything I ordered. The flooring OSB requires 1/8 spacing for expansion and contraction. WTF I'm not building a fucking boat! Might be the waxy shit the use to make it? I don't know. The shit's out side spaced to degass right now.

Pulled the rest of the deck off. Wow. They had some sort of water protection sheet that did not work at all, total fail. I wish I could get pics here cause you would love it. The rot is beyond rot, No Idea how I am going to get a new sill plate in here, and 12 foot long ain't gonna do the job lol. More likely I need another 4 foot to finish this area.. Going to beat up my phone tomorrow cause my camera died also, this needs to be pictured for sure.

I am assuming a crawl space. You will need a couple bottle jacks and blocks on each end of a temporary beam to keep the joists up while you replace the sill plate. If it is that bad, you may need to replace the rim joist and sister some scabs on the joist ends. A project for sure but doable.