Two.....as of right now...I don't put anything treated where the horses could chew on it. How many stalls are you putting in?
That's kinda what Mom and I thought. Thanks!We used plywood. Iv'e only had one of my horses chew on things, but better safe than sorry. I wouldn't suggest OSB because it contains adhesives.
We get rough cut lumber from local sawmill. Use it inside and out. Cost more but holds up better . For a tighter barn for weather used OSB under outer wall.OSB just doesn't stand up to weather and horses like other products do. My barns are mostly sheeted with exterior grade plywood, 1/2-3/4" thick depending on the building, and the mare barn has a couple of walls made from lumberyard seconds of 2x4s we got a good deal on.