Thanks.
The metal work end walls are Miniorb corrugated iron (spark and fire resistant) over rock wool insulation. no finish needed
The wood work end walls are nearly all covered with cupboards and shelving. They are just gyprock (cheap) over the bubble wrap type insulation and white plastic paint finish
The floor is 2 coats of Berger Jet dry "Blue Ridge"
My shed fit-out thread has more details https://www.woodworkforums.com/f245/bobls-shed-fit-134670
Since 2011 when I built the shed I have recoated the metal work end of the floor once but it needed it again probably 12 months ago. The wood work end can probably go another 12 months before recoating. It depends how much work I do in each end and in the last 12 months it has been nearly all metal work, plus metal swarf from the DP and lathe, and welding slag really chops up the paint. I doubt it would be any different with two pack epoxy.