Acrylic or fiberglass?

Hi, remodeling the bathroom and putting in a new tub and surround. My questions:
1. Fiberglass or acrylic- which is best?
2. I've heard I have to "bed" the tub-is this true? What do I bed it with?
3. What material should I put behind the surround-greenboard good enough? Do I need a moisture barrier underneath the greenboard?

thanks much-John

I personally prefer acrylic over fiberglass. Bedding the tub means setting it in mortar. What you want is to support the bottom of the tub across the entire surface. It just feels much better, and it helps prevent flex and cracking of the surface. Most of the tubs (not all) have reinforcing ribs, and nothing inbetween. Filling those areas with mortar gives it firm support and helps prevent the flex damage.

thanks-greenboard behind the surround?

Is the tub also plumbed for a shower? Green board is moisture resistant until it is nailed/screwed in place, then it leaks. Will this area be tiled or painted? If tiled, you'd be better off with cbu. Behind the cbu, you put up a vapor barrier (either tar paper or poly) on the studs. This board is great on plumbing issues, if you are going to tile, I suggest www.johnbridge.com for help.

No tiling, going to put a tub/shower surround on 3 sides. So I assume greenboard is OK in that application. Also I assume no need for a vapor barrier, since supposedly the surround is waterproof?
John