We did a complete floor replacement for our
Burro. This was a huge undertaking and after owning it for two years just completed it enough to squeeze in our first camping trip Labor Day week.
Different eggs have different floor construction. The
Burro has plywood sandwiched between
fiberglass (top and bottom). The problem with this is...if you are not careful of the holes on either side, you can potentially trap moisture and the wood will begin to decay. When we pulled out the floor in our 20 year old
Burro, 50% of the floor consisted of 1/16" or so of
fiberglass on both sides holding wood chips in the center.
Our new floor is 3 layers of polyester fiberglass on top, marine grade plywood in middle, 3 layers of polyester fiberglass on bottom, 2 coats of black gel coat, various spots of floor grade polyurethane. We had a professional fiberglass company create the flooring sandwich and they suggested that any fiberglass patching be coated with some sort of sealant...especially underneath and in wheel wells. They said that although fiberglass is hard it is somewhat porous and should be sealed. Tubs, shower stalls, other fiberglass vessels, used where water is present is sealed with gel coat.
When attaching the egg to frame through the floor, we predrilled through the floor, filled the hole with marine grade sealant, used stainless steel bolts, and covered the bottom and wheel wells with polyurethane...just to be sure. On the drain hole, we cut a much larger hole, closed it up again with polyester resin. Redrilled for exact size and inserted drain. Sealed that with polyurethane as well. We make sure all holes (screws, bolts, drain) are sealed properly because we want this floor to outlast us.