Plywood/OSB/Waferboard

[ahuffman]

Does anyone have any experience positive or negative in using OSB (Oriented Strand Board) or waferboard in layout building applications where plywood has traditionally been used?

[MisterBeasley]

If it has the properties of particle board, it is very susceptible to changes in humidity.  It will expand and contract, and if constrained on the ends, it will warp as well.  Even plywood will do this to some extent.  Generally, painting plywood will help manage the moisture issue.

To me, that's another good reason to use foam.

[Midnight Railroader]

I certainly haven't had positive experiences with it.

I'll never try to go cheap like that again. Quality plywood makes a big difference.

[ahuffman]

Midnight Railroader, could you elaborate on your bad experience.  I'm definitely not talking about particle board here.  In this region, OSB has pretty much completely replaced plywood in floor and roof decks as well as wall sheathing, and some heavier grades are being used in certain framing applications.  Some of it has better structural properties, at least looking at the numbers, than most plywood and it's made with exterior glue.  I'm thinking about using it for cantilever brackets for a section of double-deck around the wall layout.

[CSXDixieLine]

I have not used it but I do believe it will warp and twist quite easily. It is really designed as a cheap sheathing material--in this application, warping is not a concern since it is fastened to sturdy framing with lots of nails or screws. In fact, I can not recall seeing a stack of OSB at the building supply stores that is not already warped and twisted. Jamie

[Midnight Railroader]

I'm thinking about using it for cantilever brackets for a section of double-deck around the wall layout.

In my experience, it does not have the structural integrity for that kind of application and will bend or warp over time.

[cacole]

Unless you use double the thickness of a comparable sheet of plywood, OSB has no structural integrity and will warp or sag very easily.  It is not as waterproof as plywood and will separate into many pieces if you use too much water during your scenery application.

[Autobus Prime]

Folks:

I don't like to work with OSB, because it can get splintery, but I've used it to build solid-top model railroads without any problems. I think that in a normal interior room, with reasonable bracing, there shouldn't be any problems. I can't say I've ever had any problems with *any* material warping, and I live in the Northeast, and build my railroads in damp basements. I've heard of a few other modelers using OSB, too.



Furthermore, OSB has good structural integrity, comparable to plywood. It will certainly NOT delaminate if you get it wet while making scenery, any more than plywood will, which is also glued together. Heck, my one RR on an OSB table had a real-water lake and plenty of spillage, and held up fine (this can not be said for the other scenery that the water spilled on).


As I said, I don't use it, because I don't find it pleasant to work with, but that's the only reason.

[tinman1]

The thing to keep in mind is that it is Orientated Strand Board. That is to say the strength lies in one axis. On the back (smooth) side there will be some information and some arrows. The arrows indicate the axis. This is typically lengthwise (8' direction). For what you are using it for, it is comparable to its equal in plywood. Both have their warping issues when they get wet, but this is wet. Like being rained on (one side) and being subjected to heat (sun). Hope you are not in this enviorment. As for normal humidity shifts, as long as it is supported and fastened well, it will be fine. I'm not talking about "humidity" as in you can use the naturally occuring moss that tends to grow on the layout type humidity either. It will expand and contract (same as ply). To minimize that, just seal it (same as ply, or wood in general).

[tinman1]

As an afterthought, alot of people have something very similar in their house. Wood I-beams support many, many floors in houses, with osb decking on top to boot. As long as they are stiff enough to not tilt, they are pretty strong.

[THE.RR]

I can definatly say do NOT use waferboard, and probably OSB unless it is very well supported.  I am currently replacing a 4' x 24' section of wafer that had been topped with the Homosote substitute but not painted on the bottom.  It was supported on the 4' edges and about every 4' along the length.  After 10 years it was sagging inbetween the supports.  I tried bracing up 1 section a few years ago, but the warp is too strong, and is showing up again. 

I plan to go back with 5 layer half inch ply and add support between the existing, so the spacing will be closer to 2'.  The good news is that track had never been laid on that section of the layout (only a temporary return loop).

Phil

[cmrproducts]

OSB, when properly supported will not sag.  I had Plywood of similar thickness sag when I built one of my early layouts due to the fact I did not properly support it with crossmembers on 16" centers.

I have also found many other first time layout builders do the same thing as I did and try to cut corners with benchwork.  It only comes back to get you in the end.

I am using OSB for my subroadbed on my latest layout (2500 sq ft).  It is now 5 years old and the OSB is not showing any signs of sagging.  But then I am running joists on 16" centers and usually a lot closer in places.

It all comes down to this if you cut corners, it will be a problem forever.

I could never understand why, if you didn't have the time to built it right in the beginning yet you can seem to find the time to go back and try and fix it after there is a problem due to lack of proper planning!?

I learned this early on with my first layouts and don't want to have try and fix things after the fact ever again - I ain't getting any younger!

BOB H - Clarion, PA

[Autobus Prime]

I could never understand why, if you didn't have the time to built it right in the beginning yet you can seem to find the time to go back and try and fix it after there is a problem due to lack of proper planning!?

I learned this early on with my first layouts and don't want to have try and fix things after the fact ever again - I ain't getting any younger!

cmr:

Well, that's what happened to me, too...I learned it early on, before high school, in fact. I had some horrendous structural nightmares (did you know that two inverted-U things nailed together out of odd lumber can support a piece of 7/16 OSB without flexing? Right, I didn't either.) Other people build their first layouts much later.