Make sure your walls are prepped well for epoxy. If you know what type of paint was used prior on the walls, it would be good info to relay to the sales rep. Ours told us that applying to epoxy on certain types of paint will actually cause the old paint to lose adhesion with time and will begin to peel off the old paint along with the new, its all in the prep work. With that being said, we sandblasted one of our locations and still only got a good 3 years out of paint. This is the main reason we use wall paneling everywhere we possibly can. We are currently using Sherwin Williams Waterbased Acrolon 100, its a waterbased urethane, for exterior walls and so far it looks good but time will tell.