BBZ said:
So.. my camper (old grandby) came with 3 layers of 3/4 osb.. I think someone added it to add height to it, but not really sure. Anyway, it add a lot of weight. I have decided I am going to remove it and add new floor.
Do you suggest OSB or Plywood?
Seeing as this is from 6 months ago, you've probably already replaced the floor by now. But for future reference for everyone else, Menards (mostly eastern US store, but there's one in Cheyenne WY where you bought your camper) is a really good place to go, good prices and a good selection of everything. They're more than just a Hardware / Lumber Store, they sell some food, appliances, camping / hunting gear, wood, interior decorations, lights, whatever. But they have a good Marine Grade Douglas Fir plywood, right now on sale, 3/4" 4x8 7 ply for $70. Normally $78. But that's probably what I would go with.
Now, if you want to go all out, and money isn't an issue (at least, not much of an issue) I would look up Coosa Board. Coosa board has been used for over a decade in the boating world making replacements for old plywood transom areas (That's where big heavy motors are mounted) and for the decks of boats, swim docks, whatever else. It's 30-40% lighter than plywood, has at most a 1% absorption of water (plywood is near 40-80% depending if it's sealed or not) and it's stronger than plywood. Now, the downside is it's hard to find it to buy it, mostly because it's a commercial grade product, and because it's for boats, so if you're not by an ocean or a very large boating area, it's not easy to find. And, for a 4x8 sheet of 3/4" thickness, you're looking at $300-$400, a sheet. Like I said, this is only for people that don't care about money lol. But that being said, it's extremely light weight, extremely water proof, and very strong, if you combined it with the aluminum frame of FWCs, your camper will probably outlast you with good care. All you'd ever have to replace (possibly) is the canvas and the siding, or maybe the roof. But those are relatively easy to change out, without having to replace the entire interior of the camper.
And just a side note, I went to Montana Tech for Construction Technology (basically I learned how to be a carpenter and some of the sizes behind stuff) but our shop teacher always joked and said OSB stands for 'Oregon Sponge Board' lol, because it soaks up with so much water and turns all sponge and gross. If budget is an issue I'd literally buy anything other than OSB.