I have no intention of coating the floor. Anything you put on needs maintained over the years. 3,500 psi concrete is pretty tough on it's own. As far as truss layout it's pretty obvious by looking at the pull down stairs. Or tapping with a knuckle. Also in the photo is a trap door. The stairs get narrow at the top due to the lift springs. Something I don't care for but too late now. The trap door will allow for full truss space width and will have a high anchor point. This will allow moving stuff up and down and hanging an elk!