When replacing a shower pan is it necessry to redo the entire walls

When replacing a shower pan is it necessry to redo the entire walls

I assume you're talking about a custom tile shower. The answer's no you don't. The tiles will have to come off the walls past the point where the pan ends. Then you can mud the floor and install the rest of the tiles over the pan. Good luck, Tom

When replacing a shower pan is it necessry to redo the entire walls

Only up to the first or second course of tile.

The key is to leave yourself enough room to tie the new membrane into the old membrane.

You need to wet mob it though for water proofing