its my sons warehouse. changing it from office space to retail store.
no smoke damage?
(it's in fire/smoke damage section here)
if not...give a quick hand wash with TSP and rinse
make the first coat of paint a bonding primer (Glidden Gripper is a good product)
It can be color tinted too if your son is painting a color other than white
you won't have to worry about paint sticking with the bonding primer
(that's what it's made for)
I presume you're going to rent (or have) a paint sprayer?
you can buy a good "throw-a-way"* sprayer for about $300
Paint like a professional with the Magnum Project Painter Plus Paint Sprayer. This sprayer has adjustable spray speeds and fully adjustable pressure so you can apply a polished coat of paint to decks,
www.homedepot.com
Only reason I call it a "throw-away" is because the pump isn't rebuildable like the contractor grades.
But they'll last a Homer a good long time
..L.T.A.