depends, whats the firecode for the wall assembly? share photos and a plan, regardless drywall has no place in wet areas period, if there is a firewall concern that can be acconplished w cbu

Thanks for the response.

The overall plan is to replace the existing one-piece fiberglass shower/tub combo with a solid surface shower, and to do this with as minimal damage to the remainder of the bathroom. Step 1 is demo, which is what I am doing now. Step 2 is rough in plumbing, which will be done by a licensed plumber. Step 3: The solid surface fabricator will measure for and install a solid surface pan. Step 4 is to install the solid surface substrate and any necessary blocking. I was going to hire this out as well, but am leaning to perform this portion myself. I am leaning toward Densshield in this application with additional water-proofing at the corners and nail-heads. Step 5 is to repair and mate the drywall with the solid surface substrate. Step 6 is for the solid surface fabricator to install the shower walls.

The walls in question are interior residential walls, so no special fire-proofing should be required. The drywall in question, which is actually green-board, is outside of the shower area and butted up against the fiberglass enclosure.

In some of the videos I saw, they tried to keep the cutout confined to just outside of the fiberglass lip. In my case, in doing so, on one side the drywall is no longer attached to the stud. In addition, it would seem that I would need some room the tape the joint so having it close to the new shower enclosure would not be a good idea.

I will try to get some pictures later on this evening.

OK, last photo is the before-the-demo photo. Other photos are after demo. Again, looking for best way to demo out the drywall outside the shower area.

You need to pick your pan and solid enclosure, and then follow the directions for those units.

For example, some pans will be installed right up to the studs, and will have your wall underlayment (cement board, etc.) come down to the pan lip, then add caulk/sealer for the gap. The final covering (solid surface or tile) extends down over the caulked gap and the bottom of the solid surface is caulked to the pan. This was the directions for a Dreamline unit I used. Other products may have a different method for getting a good seal.

Solid surface enclosures may allow installation over standard drywall (because the enclosure should be waterproof), but I don't really like that solution. For best long term results I would use something like Kerdi board on the walls and follow all directions for making the proper seal to the pan (follow directions for the pan). After that you can do just about whatever you want on the walls, since its completely waterproof. Kerdi board can be extended outside the shower area a few inches and then blended in to drywall with standard joint compound.

Bruce