How would you build a bathroom?

I have a blank slate. The house is 1930s lath and plaster, I want to try my hand at it because it's small. My dream is to have a wet room, with a drain in the middle of the room. Can I sufficiently water proof plaster with the soap and olive oil mix? Does anyone have any experience with this? I was thinking tile flooring. Facebook  <<< video of the demo. The whole floor was rotten.. it's getting a new subfloor tomorrow after replacing the bad wood and getting it leveled.
I am looking into making big handmade tiles at a local studio and also generally keeping my eyes open for a cheap deal on the local market places.  Waddayathink?

A wet room is really smart, especially with limited space.
Might be worth checking your local tile shops. For our last house, we scored several types of really nice clearance tiles. I could not have made them for the prices. (And tile can be hard to make in bulk)
We did the walls in stone tiles ( an auction deal) but did use the bathroom drywall boards behind them. Was still in perfect shape after 15 years when we moved. We used a cast shower base for the bottom but I've seen friends have tiled floors that hold up as well.
There are large tiles being made now that look like marble as well as glass and steel ones.
You never know what you will find at the Habitate for Humanity ReStores. If you have your sizes on hand you may be able to do some cool designs with mixing pieces and tile types.

About what is the number of square feet you're working with?

1930's house may not originally had indoor plumbing.

You mention "level" but in fact if your goal is a wet room I would treat the whole room as if it was a shower stall making sure that it was high at the edges and every bit sloped to the floor drain.

Jay Angler wrote:About what is the number of square feet you're working with?

1930's house may not originally had indoor plumbing.

You mention "level" but in fact if your goal is a wet room I would treat the whole room as if it was a shower stall making sure that it was high at the edges and every bit sloped to the floor drain.

Yes.. the sub floor is the step I am approaching in the coming days,  I certainly will address the sloping carefully. You are correct,  the house has a plumbed addition at the rear. I am pretty sure they added to the front of the house the same time. .The bathroom is 8x5.

I did one like this recently,
- I sloped the whole floor to one end,
- I had a made to measure trough to go the full width of the room.
- I used waterproof plaster on the walls with stainless steel angle section made to fit, behind the plaster and sitting with sealant on the floor material.
- The floor was 19mm thick fibre cement sheet.
Past experience has shown that central drains always leak, the custom made trough was lower cost than a standard one and was perfect, with the wall draining into it.
The floor cannot leak or rot anything under it.
I did not use any waterproofing compound or service, just good design and materials.

Never heard of this, so thank for asking:

Look up youtube videos on making a shower floor pan. We had to replace an incompetent professional's 10-year-old floor in a 6' x 8' custom built shower which had rotted down into the floor joists. We rebuilt it with a proper sloped subbase, membrane, and tile bed, laying standard tiles on floor and some walls. It is still working well a dozen years later.

If you need to replace or shore up framing, setting the new top a couple inches below original level will make it easy to match the floor outside the door.

If this is not done 100% you can wreck a lot. There is no advantage of a wet room. Just get a "normal" shower basin (80x 8o cm) you will need that space anyway.
Even if done conventionally, you need to seal the walls and everything VERY well. A wet room looks modern, but any leak causes problems, and a house with mould is about the last thing I would like.
If you choose your dream, get a very good professional. Also, the bathroom needs a good ventilation - the window has to be used after every shower and be big enough.

Nicola Bludau wrote:If this is not done 100% you can wreck a lot. There is no advantage of a wet room. Just get a "normal" shower basin (80x 8o cm) you will need that space anyway.
Even if done conventionally, you need to seal the walls and everything VERY well. A wet room looks modern, but any leak causes problems, and a house with mould is about the last thing I would like.
If you choose your dream, get a very good professional. Also, the bathroom needs a good ventilation - the window has to be used after every shower and be big enough.

I think I have decided I can't afford it.. the delay being a big factor.
I have decided to go with a tub after much consideration. I will still try my hand at applying a plaster finish. I am somewhat obsessed with restoring the old walls back to the lath and plaster. I'll source some tile for flooring and around tub. I will have to plaster the remaing walls before the sink can be mounted. It has no vanity,  it attaches to the wall.
Off to search out second hand tiles today... that's my base!

The issues I would consider when planning a project like this:
1. Climate: We are very dry in the summer, and very wet in the winter. This change causes wood to expand and contract, thus what you put on top of the wood to be your bathroom floor has to allow for that change without cracking.

2. To quote M W Turner, "nothing man builds lasts forever, nothing the gods build last for eternity"  - so whatever you end up building, bathrooms *need* maintenance and need a critical eye watching for things like old sealants peeling etc. Making sure maintenance gets done as needed is the best way to keep things working long term.

3. Do lots of research, particularly about longevity, before making decisions. Remember, the "in" colour today, is totally out in much less time than in the past. I tend strongly towards neutral colours for fixtures that are difficult or expensive to replace. Then use things like towels and bath mats to make the room bright and cheery.