Designing Kitchens and Bathrooms - Help with mud floor.

I have a 6x6 area next to my water heater that needs to be mud and tiled. I was going to use hardy board but the contractor said use a mud floor. The area is the slab but with pieces of preexisting floor on it that we couldn't scrape off. I have mixed mud before and applied it in a shower but never on a regular floor. I have some questions like, do I make a curb out of two 2x4s to frame around my water heater? Do i tile the curb then? Also what do I put down first then, the curb the felt the wire the mud? I never used felt or wire just the vinyl sheet you use in the shower, so I do not know the steps.

Im not clear on exactly what you are trying to do. Are you going to tile around the water heater or tile and then install the water heater over the tile? I'm confused about your question about the curb?

You dont need the felt and the lath over a slab, that stuff is for plywood subfloors. If you are gonna go at least 1 1/4" thick with the mud, then you dont need to do anything. If you are gonna go less than that in thickness then you'll need to bond the mud to the slab with thinset. The way to do that is mix thinset loose, trowel it onto the whole slab area and then immediately put down the mud. Under no circumstances should you go less than 3/4". Im assuming that the prior floor stuff that you cant scrape off is thinset and it is well bonded to the slab. If not, then what is it?

The water heater is there already on wooden blocks. I want to put a curb of two 2x4s screwed together in front of the water heater, and just tile up to the curb . Eventually a door is going to go there to hide the water heater from the rest of the small area. The tile is going to go up to the curb on one side and a step up on the other side so I can go as high or low as i want with the mud...I figured I am just going to leave the curb, and since its concrete floor I don't need to use thinset felt/paper or wire lathe, so I am just going to throw down about 1.5 inches of mud, make sure its level, wait a day, spread some thin set,tile, wait a day, grout. I just wanted to go through the steps so I didn't miss anything. Am i correct that that is all I have to do? Buy mud mix it spread it and level it, wait a day buy thinset spread it and tile, wait a day, grout? No wire /felt or anything else needed besides thinset, mud, tile, grout, grout sealer, 1/2 inch trowel, bucket, mixer, wet saw, 4 foot level, screw gun and screws and a 2x4?

Sounds like you got it to me.

noone told me i had to add sand to the Portland cement type 1/2. So i mud the floor and it came out real crumbly. Should i rip it up and redo it? i didn't tile or do anything else. i coulda swore i never added anything to the cement when I did the mud floor in the shower.

Im not sure what you used for deck mud. It should be a mix of 1 part portland cement to about 4 to 5 parts of sand. The proportions dont have to be perfect. 1 shovel of portland to 5 shovels of sand should be good. You need to dry mix everything together real good first. Then just add enough water so that the mix will hold together in a ball in your hand. If your not sure about how to do something or not sure about what materials to use, dont be afraid to ask. The only foolish questions are the ones you dont ask and there are some good people here who are happy to help. Sorry but yeah you need to get rid of what you have. In place of buying portland cement and sand you could by sand topping mix and some extra sand. Sand mix is typically 1 part portland and 3 parts sand so you should add some sand to the mix accordingly.