Plywood vs OSB
Plywood vs OSB
(OP)
I am looking at a project from another engineer where the roof deck was designed as 5/8" plywood. The client wants to go to 3/4" OSB. My wood books are in a disarray, can anyone post a link to allowable capacities of 3/4" OSB.
Thanks,
Thanks,
Kaiser






RE: Plywood vs OSB
Kaiser
RE: Plywood vs OSB
Kaiser
RE: Plywood vs OSB
OSB is actually stiffer as both shearwall and diaphragm. Capacity (or, more precisely, reference nominal unit shear capacity), for the same thickness is exactly the same for OSB and Plywood.
RE: Plywood vs OSB
thanks for the quick responce. Where would I find shear values for both. I know they differ for the nail spacing and blocked/unblocked but say an idiot like me wants to see the plywood allowable values and OSB values, where would I look.
Plus, from your comment it appears that OSB=Plywood for same thickness in shear, is that right?
Kaiser
RE: Plywood vs OSB
The tables are exactly the same, save for the Ga values.
And yes, for the same thickness, the nominal capacity is the same. Keep in mind that the table lists nominal (not allowable) capacity, so you must apply your safety (or phi) factor.
RE: Plywood vs OSB
The Panel Grades for shearwalls & diaphragms are APA Structural 1. APA Rated Sheathing or APA Rated Sturd-I Floor. The panels can be manufactured from OSB or plywood. As long as the panels have the same Grade Stamp they are interchangable (but I wouldn't mix them on the same job). The engineer calls out the nail size, panel thickness and nominal width of framing and the codes give you the allowable shear in pounds per lineal foot.
I hope that this helps.
RE: Plywood vs OSB
Double posting for the same information is not allowed. I am redflagging the post in the wood forum. Please keep this in mind in the future.
Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask
RE: Plywood vs OSB
Apologies for the double posting, I wasn't aware.
Kaiser
RE: Plywood vs OSB
Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask
RE: Plywood vs OSB
They don't want you walking away from here with the possibility of twice as much information than what you deserve, so you shouldn't double post. You can just imagine .....
RE: Plywood vs OSB
Form TT-047
RE: Plywood vs OSB
Kaiser
RE: Plywood vs OSB
RE: Plywood vs OSB
So in conclusion, OSB, Plywood, Composite panels all have identical properties in shear and gravity loading provided they are the same grade.
Kaiser
RE: Plywood vs OSB
RE: Plywood vs OSB
Jason A. Partain, P.E.
www.myconstructionfinds.blogspot.com
RE: Plywood vs OSB
http://
RE: Plywood vs OSB
Dik
RE: Plywood vs OSB
RE: Plywood vs OSB
My thoughts exactly, about occasional double posting...., where to ask the question. If only everyone frequented every forum, all the time, one post might catch them all.
My thoughts exactly, about..... Exactly. Oh damn, I did it again, almost three times.
Otherwise, I was just pullin Mike's leg, or his post, a bit.