Designing Kitchens and Bathrooms - mold behind shower wall

Hello all,
I was showering the other day and noticed the grout lines of my shower were cracking. I figured that the shower was now up for an upgrade. I started pulling down tile and found it was that the tile was adhered to normal drywall. one foot sections of drywall with the tile still attached started coming down with great ease. I have what i consider lots of mold behind the drywall. some is black and some looked like white cobwebs but much thicker. it is mostly just attached to the back of the drywall. I pulled as much down as i could at the time and mixed some bleach and water and sprayed everything and closed the door. I'm gonna get a mask tomorrow and rip out the rest. But my question is how concerned should i be. I would like to rip it all out, spray it down and let it sit for awhile. Then durock and put up new tile. I know mold is nasty stuff, so i wanted to ask. I love this site.

Hi.

Wear some gloves and a simple dust mask. Clean it out as you described and allow to completely dry out. Then hang plastic vapor barrier against the studs, then install your cement board.

What is the shower pan made of? Tile, fiberglass. etc?

the pan is fiberglass. the mold doesn't seem to have effected any of the studs behind the wall. When you describe a plastic vapor barrier, is it as simple as stapling plastic sheeting to the studs?

Yes, just staple them to the studs and allow the plastic to drape down into the pan. Trim the plastic when the cement board is installed. Keep the board about 1/4" off the flange of the pan. The plastic is usually 6mil.