How to build a toilet in a tiny house with steel structure?

[Albertxt]

How do I built a toilet? I have a tiny house made from steel structure. I filled the cavity with rock wool. So now do I use cement board and then waterproof membrane and after that I am not sure what goes in between the tiling and waterproof membrane. Hope any great soul out there will reply and enlighten me....Thanks

[EricL]

Hello @Albertxt 

Welcome to the Bunnings Workshop community. It's sensational to have you join us and thanks for sharing your question about building a toilet in your house.

I suggest having a quick look at this guide - How to plan a bathroom renovation by @Adam_W. Generally speaking, it would be best if you engage the services of a licensed plumber. They will be able to tell you where the toilet can be positioned and where the pipework will pass through. They will tell you where the concrete and tile will need to be cut and how deep they will need to dig. Once the that has been established, you can then plan on size and shape of the toilet. The rest of the construction such as the waterproofing and tiling can then be finalized by the plumber as well. 

Please note that adding this particular room to your house will need a proper plan from a draftsperson along with a permit from your local council. 

If you have any other questions we can help with, please let us know.

Eric