On 1/12/2012 11:07 PM, Robert Neville wrote:
wrote:

Why can't I (or a sheetrock guy) just tape the seam where the
backer board and the sheetrock meet? Is backer board thicker
or thinner than the green board that's already up?

Because you NEVER have an unsupported long (vertical) joint between
drywall and drywall, drywall and backer board, or backerboard and
backerboard.

I understand that, no problem. It's one of those 'I can show
you better than I can tell you' things. For sure I know that
drywall/etc needs to have the edge land on a stud.

Any flex will damage the joint. There IS an option when a
wall is open. Add another stud at the point the 2 panels will join.

That was one of the three solutions the guy mentioned.

What he said. And that you don't tape the seam between sheetrock and
backerboard. Tile should completely cover the backerboard.

The last sentence is actually what I was asking. I didn't understand
just *why* the backerboard has to be covered by tile and not just
taped/whatever to match the drywall.

I'm just going to live with the tile extending farther by a course
past the shower. Thanks for all the advice.

nancy