OSB vs Plywood...

[midget_farms]

PT wood is fine around chickens - the new kind uses copper instead of arsnic which is much less toxic.

That said I don't think you can claim your birds or eggs are 'organic' if you use PT lumber. But honestly the birds would need to eat an entire 2x4 to get enough copper in them to do any harm. The stuff is really safe these days.


I forgot to answer the original question though.

OSB works perfect if protected from the weather - under shingles or siding or even paint. 1/2 inch should be enough.

Me personally though I use 3/4 treated ply for my floors - I just want them to out last me & I have a long way to go.

3/4 is stronger & will not bow under your weight - if you are not walking inside the coop 1/2 or 5/8 will be more than enough.

OSB isn't the greatest if it is exposed to prolonged wet - like winter snow piled up against the bottom of the coop. In fact ply has trouble with that too unless you get an exterior grade.

Exterior grades use more waterproof glue & hold up better.

Interior grade will not last long in the rain - OSB or ply - but ply is still better.

 

[ashleyrae211]

Is there a good sealer and paint that is not toxic to chickens?

 

[Fred's Hens]

OSB and/or plywood, even exterior grade are only designed for exposure to moisture X number of times. One, three, but limited number. They're great for walls, roof sheathing, etc which is covered and protected from weather with roofing materials or siding materials. The application and use is interchangeable, for the most part, so go with whatever floats your boat, from a budget and availability stand point.

Where flooring moisture, cleaning, hosing out, ground moisture, etc, is expected, a weather resistant product is going to last much, much longer. Modern pressure treating chemicals are more eco friendly than they were years ago. But, not sure even the newer products pass total muster with the stiffest organic standards, however, if that's important to you. Just do your homework. Last time I looked, treated plywood had skyrocketed in price.

 

[Izzymoon]

curious, would you use cement board (blue board) on the interior walls and floor? I know they use it bathrooms, basements and coops can get damp at times (weather pending) I do plan on using some sort of either vinyl flooring or something similar on the inside for easy cleaning. Probably an insulation between the plywood and the cement board. (I'm in New England where the winters can be harsh)