In the intrest of attempting to save a few bucks by going dumpster diving, I considering using 3/8 inch OSB (Oriented Strand Board) for my subroadbed. Has anybody used OSB for this purpose.
Choo Choo Willie
That same subject came up two weeks ago. The answer then, as now, is NO! OSB has to structural strength and will sag between supports unless they are very close together.
I beg to differ on this
My 2000 sq ft layout uses 99% OSB (7/16) and have no problems and this layout has been in operation for 10 years now!
When using OSB - it has to be supported properly (max of 16" on center) and be painted.
I love how these Urban Myths get started - just because someone doesn’t properly build the benchwork and then blame the problem on the materials used. (and YES I use Homasote sub road bed too)!
Same goes for using the so called furring strips for the benchwork - again if properly supported on 16" centers it will easily support me walking on my layout (260 +)
BOB H - Clarion, PA
I’m glad that you haven’t any issues w/ the use of OSB. The OP wants to use 3/8". That is a definate NO. Your layout must be in a fairly dry enviorment and you are using the 1/2’ (7/16) and properly supported. Not sure what your construction is, calling for subroadbed. If it is decked or strips of subroadbed on 16" risers. Thin strips of OSB under 2 1/2-3" will not hold/ support over time. It’s not even a decent product for wall sheathing, especially if wet a few times before covering w/ sidewall. I have seen the 7/16 grow to over 5/8" after one rain, makes for a “lovely” header in your framed house when the wall thicknes expands to well over 3/16 for every opening. Now when framing w/ this crap, I need to build all structuaral headers w/ 1/2 ply. I need to use this “stuff” if speced and believe me the is no substitute for quality fir plywood. Yes this may not actaully relate to
I’ve used plenty of nominal 1/2" (7/16") OSB for subraodbed. I provide support at least every 16", and don’t use it in narrow strips (i.e. I only use it for wider areas like yards). I’ve had no problems with the material, including none with the water in scenery construction/finishing (plaster, ballast glue, etc.). I would avoid 3/8" OSB, or using it in narrow sections as for single-track roadbed. OSB must usually retain a greater width to maintain its structural rigidity, and the 3/8" thickness doesn’t have much strength.
bogp40
It is too you have had problems with OSB - BUT - just because YOU had them doesn’t say everyone else will!
This happens all too much on the forums and it is no wonder all of the Nubes are confused!
And for the record - my basement humidity is a fairly constant 70%.
Which is way too wet for my likeing but unfortunately I can not change the value much even with a Dehumidifier as the layout was built at this percent and lowering the value much more causes too many other problems.
SO - by your standards - my layout should be falling apart. Well it isn’t!
Keeping the humidity level the same at what the layout initially was built it keeps everything constant.
I have large areas covered (YARDS) as well as layout sections in widths down to 3 inches (usi
Actually, I glue 3 pieces of osb precut roadbed together in a sandwich resulting in a nominal 1" roadbed. Do the same with spruce plywood. Humitity is about 60% year round.
It worked for me years ago and the OSB now is pretty much impervious to water when used the way I describe.
Keep in mind I’m talking Oriented Strand Board, not particle board or medieum density fibre board.
Choo Choo
You could have avoided a lot of argument about the use of OSB if you had explained that in your first message.
I think this gentlemen likes to stir stuff up. But to answer his question about 3/8 with out laminating the plywood. The structural support of the bench work is based on the thickness of the material placed on it. The thinner the material the closer one spaces the structural members underneath. For example: If you were to use 5/8 or 3/4" Plywood your “joist” could be two OC(On Center), 1/2 16" prefered spacing would be 16" oc. 3/8. I would recommend 12" or closer spacing.