Posted By FBBP on 09 Dec 2012 10:20 PM
One thing to think about when comparing plywood and osb. OSB never delaminates. It might swell (only if prolonged exposure to moisture) but usually just the top flakes will swell and or loosen. Plywood has a bad habit of delaminating and more so if exposed to moisture. You can glue and screw a plywood floor and still have squeeks because of internal delamination.

I have seen OSB swell to double its thickness, I have never seen plywood do that

Posted By cmkavala on 10 Dec 2012 07:54 PM

Posted By FBBP on 09 Dec 2012 10:20 PM
One thing to think about when comparing plywood and osb. OSB never delaminates. It might swell (only if prolonged exposure to moisture) but usually just the top flakes will swell and or loosen. Plywood has a bad habit of delaminating and more so if exposed to moisture. You can glue and screw a plywood floor and still have squeeks because of internal delamination.

I have seen OSB swell to double its thickness, I have never seen plywood do that

Chris - it might have to do with the different manufacturers. I have seen particle board swell like that but not oriented strand board. Yes it will swell a bit but not to that extent. At least not the local product that we have tested by leaving it in a puddle. When faced with inclement weather I will always choose osb over plywood. I hate squeaky floors!

Posted By Alton on 10 Dec 2012 07:23 PM

Posted By Dana1 on 10 Dec 2012 02:03 PM
It's true that plywood handles moisture loads far better than plywood (<read, "OSB") due to the greater exposure of end-grain (to wick surface moisture into the wood) and the higher levels wood-sugars created out of the lignin & cellulose by the heat of processing it.  But it's still pretty good stuff and will last as long as plywood or planking if you treat it right.

Dana1,

I do not believe that the paragraph above says what you meant.

Thanks! (I need an editor! )

Mike is 100% correct. OSB is an awful mess after it gets wet.

Posted By Bob I on 09 Dec 2012 05:16 PM
What do you folks think of Advantech?

I used it for the subflooring in the one ICF DIY house I built a little over 4 years ago. Wouldn't hesitate to use it again. As I recall it was priced between plywood and OSB, and is stronger than either one. I used 3/4" over joists spaced at 16" o.c. and my floors are rock solid. On the John Bridge tile forum the tile guys swear by it as by far the best subflooring there is to use under tile.

the biggest advantage I've seen with Advantech is that it is relatively unaffected by water - it doesn't swell when wet and never delaminates; the main problems with plywood & OSB.