What are things to consider when replacing a fiberglass shower and putting in tile and new fixtures? Appears from prior posts, that the custom pan is the trickiest part. What are the main materials or recommended approaches to a custom shower pan?

Having rebuilt 4 showers in the past 15 years, here are a few things to consider:

1. Make sure to use cement board as backing for the tiles. Some people go with cheaper green board, but you can have problems if water gets into the board. Cement board is just a little more expensive, but definitely worth it. Use cement board for all shower walls. You can use green board for the shower ceiling and other walls in the bathroom.

2. The pan under the tile floor is very important for preventing leaks. When I built my showers I found a guy who put fiberglass down on the plywood subfloor and partially up the side walls - this was not a pre-made piece but rather fiberglass cloth and epoxy built up by hand. It'll never leak!

3. Use quality fixtures - you never want to have to get back into the walls to fix something, so invest in quality. Also, now is the time to make sure you get exactly the features you want, so think carefully about things such as multiple spray heads and automatic temp control.

4. If you're going to have any built in shelves or seats - make sure they are sized properly and at the correct height.

5. For the threshold into the shower use a single piece of marble, rather than tiles. Water tends to collect and sit on this surface, and if you use tiles over time water may seep through the grout into the wood below.

6. Work with a tile store that has a good selection and where they'll spend time with you designing the layout for your shower. You can do some very impressive patterns for virtually no more cost than a plain tile wall.

Good luck!

Ebaines is correct. You should never use greenboard under tile in a shower, ceiling is fine. Cement board, Durock or Hardibacker all work well for this installation. I would recommend that you Google shower pans and look at the pre-made fiberglas pans. If you never built a custom shower pan now is not the time to start. Be careful when selecting a door. If you custom build a shower make sure that it will accept a standard door frame.