Afternoon everyone. Been lurking here for a while but haven't found exactly the answer I need. Wife and I purchased an old american four square home and are looking to add a shower to an existing tub. Want to know the best way of waterproofing things before tearing into it all. Walls are plaster, with a fiber board trim covering. Wife wants it tiled so that's the route I'll be going with it. Would love to do this myself and save a bit. But, I also want to be sure this is something I can DIY before getting into the thick of it.
Pic is of the current situation, house has no shower currently.