I have thin (5mm) underlayment inside so no worries there. The outside is plenty durable. Fiberglass work was pretty basic. Spread out the glass, pour out and roll in the epoxy, allow epoxy to dry to tacky state, more epoxy and then one more epoxy coat at least. I did the panels before I assembled them onto the floor IIRC I spent about $300 on epoxy. I got a deal on the fiberglass on e-bay and got a roll of 6 oz glass pretty cheap. . You do get a few flaws in the material, but nothing I couldn't work around. If I had to do it over again, I'd cover with canvas and use a thick primer to hide the grain (I wanted a smooth skin. That's why the fiberglass.) After the fact, someone tried the block filler primer and said it was pretty smooth after you give it a light sanding.