MHO, OSB is cr@p. Won't buy it. Heavy glue and wood bits, doesn't hold a screw in the edge worth a darn. Real wood is cheaper and lighter.
I agree that it is cr@p but we've taken care to keep it together for 3 years because we knew it was cheap. The design was so nifty and the price was reasonable so we got it. Other than the cheap materials it's made out of it has been a very functional design for a small group of hens - they free range all day anyway and only need the coop for laying and sleeping.
I made a "sifting screen" (no idea what it is really called) that is about 2'x3' on 2' legs with doubled 1x3 wire mesh to sift weeds and rocks out of the garden dirt. Cleared an area about 4' x 6', then no time so there it sits over a nice clean section of dirt. Noticed 2 of the chickens under it the other day and thought of you Sylvester. I don't know if they were using it as a place to hide from predators or just a dust bath (though the depressions are not really deep enough for that to be the case) or just SOME shade.
The little buggers will sleep next to or under anything - a trash can, a compost roller, a wheelbarrow. Ours like snoozing under the rose bush - not much cover but guess the thorns make them feel safe?