[timzr]

Both my 24 x 24 garage and detached workshop have Osb on the walls. 25 year old Garage has semi gloss white, because that's the extra I had at the time. Workshop is hall light blue half dark blue because that's what I had extra at the time. In retrospect I should have moved them together. I'm okay with the osb texture because function over form.

If you're going to use deck over paint or an epoxy make sure it can be applied to vertical surfaces. A lot are horizontal only. For your purpose to hide the texture, I'd recommend using UGL or something similar that can be tinted.

We did osb for a customer on an attached garage on 3 sides, 5/8" drywall against the dwelling. Inspector said it didn't meet code for fire rating. His resolution was to 5/8" drywall over osb, remove osb and install 1/2" on 3 walls or paint with fire resistant paint. I'd never hear of the paint. SWP ordered it, $200 gallon and 10 days lead time. That's what we did to pass.