removal of bathroom concrete floor

[MickB]

I have a small bathroom that has 2 one inch layers of concrete or mud (I'm not sure how to tell the difference)over floor boards that has developed soft spots and I wish to lay ceramic over it. It has been suggested to me to use an angle cutter to cut in front of the tub(floor is good under that and I am not removing that) and to use the angle grinder to cut up chucks of the concrete to remove. Is this the right way or is there an easier way?

[trader_4]

Not sure you have to cut it into chunks, you may be able to break it apart in sections. But sounds like the tub is on top of it? If so, you do need to cut it away from the tub so it will come out clean there. A diamond blade or similar suitable for concrete on the angle grinder should work. Kind of odd to have 2" of mud plus tile, etc on a bath floor, just from the height issue.

[gfretwell]

I have done it twice, both times the same way. Just be sure you use a damned good respirator because you are going to be covered in dust. If the floor is really that soft it should not be that hard to break up. Mine was 4" 50 year old concrete and as hard as chinese algebra. I was still able to break it up and get it out. Seal up the room as well as possible from the rest of the house and put a box fan in the window to take as much dust outside as you can. Did I tell you about a good respirator yet ;-)

[Vic Smith]

Use an electric jack hammer is you don't want to raise dust. Just use the angle grinder to score around the tub.

[gfretwell]

Just be aware there might be some pipes down there.

[Terry Coombs]

  Not necessarily , in older construction (1950's) the joists were often dropped a couple of inches and the top edges chamfered , then boards set down between the joists on cleats . 3-5"of "dry mix" consisting of 1 portland to 4 sand well dampened is then packed and leveled . Tile is set on this before it sets , adhered with a generous sprinkling of dry thinset mortar mix . Redone a few ...   --   Snag