OSB Vs Plywood in simple span condition

[mikef328]

thread507-438407

I have a RV with a soft floor. I have removed the top layer of 14" luan to expose the 1.5" square aluminum tubing and 1.5" expanded polystyrene. Overall floor assembly from top to bottom is 1/4" luan, 1.5" square tube with 1.5" expanded polystyrene between the tubes with 1/4" lun on the bottom of the square tubes and all of it is glued together with the luan board stapled to the aluminum tube. I cant get to the bottom of the underside of the assembly because of the various sewer and water tanks under the RV.

My plan is to install aluminum angle to the aluminum tube steel and place OSB or plywood between the 1.5" square aluminum tubing so the top of the wood sheathing is flush with the top of the aluminum tube. Will 7/16" OSB work or am I better off using 1/2" or 3/4" plywood? Max tube spacing is about 16" but varies through out the RV.

 

[SlideRuleEra]

Go thru the "APA Panel Design Specification". You should find that plywood, oriented correctly, is structural "better" (EI, the product of modulus of elasticity and moment of inertia) than OSB.

Especially since thickness of both 3/4" and 1/2" plywood > 7/16" OSB.

http://www.SlideRuleEra.net

 

[mikef328]

Thats what I thought. Thanks for the information.

 

[EdStainless]

Though 1/2" plywood is 15/32" and 3/4" is 23/32" with a tol of -1/32" on top of that.
Good plywood (with more plys) is easier to work with than OSB because its properties are less directional.


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P.E. Metallurgy, Plymouth Tube

 

[MotorCity]

My preference would be 3/4" pressure treated plywood. From what I've seen, OSB does not usually tolerate exposure to water or moisture as well as plywood does.

 

[mikef328]

All good information. My concern with using any treated wood is the potential reaction of the treated wood against the aluminum angle and tubes.

 

[jayrod12]

Paint the aluminum with anything before you install the plywood, and bob's your uncle, corrosion avoided from a chemical reaction with the plywood standpoint.

 

[mikef328]

Thanks for everyones input. Have some work to do tonight.