I'm remodeling a shower with a tiled cement base -- including removal of
that base. It's approx. 32" x 30" x 2" (thinner in the middle where the
drain is). How much would it weigh? Is it better to try to remove it in
one piece? Is that likely to leave the membrane intact? -- not that it
should be needed under a one-piece base, but it wouldn't hurt to use it
anyway if its still OK.

Perce