I, too, have used OSB and noted that it does not have the tendency to sag between joists like regular plywood.
Bob Nicholson ________________________________________ --- In [email protected], "scale S only" <scalesonly@...> wrote: > > Hi all -- > > I discovered, quite by accident, that OSB and related high density > manufactured wood sheets are VERY stiff. I tried to use 3/4 plywood to > bend the OSB and it went the other way â" 7/16â OSB bent the 3/4â > plywood. Now what I got isnât true OSB (Oriented Strand Board), but a > close cousin in that it uses chip wood and a lot of glue under high > compression, so that it crushes the wood fiber. The sheets were what the > builder of our development was using for shear panels and roof sheeting, and > what was not perfect they were throwing away. Being the ever thrifty > collector of such things, I got about 6 sheets worth of the stuff, from > almost full, nearly perfect sheets to odd sizes that were about a third of a > sheet. Considering that the plywood I had gotten at the local home > improvement store would not lie flat (though that was helpful in a couple of > places) I figured that free was worth the try. You might look into this > kind of product for those things you want FLAT and to stay that way. The > 7/16â version is stiff enough that it can support my heft with nary a bend > on two foot center supports > > Have fun! > Bill Winans > > Bill Lane et al -- > > Yes, there is 5/8" plywood. But unless you want to support it every 12 inches > or so, get 3/4" plywood. The 5/8" will sag between supports, but 3/4" will > not > unless your supports are farther apart than 17 inches or so. > > Why is this so? It's because of the difference in stiffness, which in the > case > of flat sheets is proportional to the cube of the thickness (not the fourth > power, as for round rod). Thus, 3/4" plywood is about 70 percent stiffer than > 5/8". > > Dick Karnes > > > > > > [Non-text portions of this message have been removed] > ------------------------------------ Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/S-Scale/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/S-Scale/join (Yahoo! ID required) <*> To change settings via email: [email protected] [email protected] <*> To unsubscribe from this group, send an email to: [email protected] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
