Tiling a Bathroom floor, stick to cement or install cement backer board?

Question

Hello, my husband and myself are remodeling our bathroom....here's the question... we removed hideous vinyle tiles and underneath is the cement floor with thin layer of black adhesive from the tiles....the floor is pretty sound except for a small crack in cement by the entry door.... should we fix the crack and tile over the cement? or thin set 1/4''cement fiber board to the floor and tile over that? and if we do use the fiber board is the thin set enough to hold it down? we can't really s***w/nail it cuz subfloor is cement. Any help is appreciated! Thanks!

Answer 1

I am assuming you are going with ceramic tile. If that is the case then you do not need fiberboard. Just tile right to the concrete floor. As for the crack either fill it in or use a product called RedGaurd. RedGaurd is a rubberized product that when applied over the crack will expand and contract and thus keep the crack covered. You can apply RedGaurd then put mortar right over it.

Answer 2

Tile right onto the cement.  If the crack has any width to it, fill it.  If it is skinny, ignore it.

Answer 3

Always use backer board! Expansion and contraction will crack every grout joint if you dont use it. The only exception is if you use a rubber based emulsion on the floor first and add fiberglass mesh. I dont know of one county in the United States that has building code other than what I stated. Look up the United States UBC (Uniform Building Code). Dont take my word for it...

Contact your local building inspectors office and ask. They are there to protect the consumer and residents against guys like the one that posted before me (with all due respect).

Answer 4

We did our 3 bathrooms ourselves. First use a solvent to get up the old adhesive. I think we used "Gesso"? We got it at Home Depot and it worked well. We went right onto the cement floor and there has been no cracking of grout in the 3 years it's been down.

Good luck!

Answer 5

the best way would be to use red guard as a waterproofing and anti fracture membrane this will help to control cracking in the future, use liberally,

you may set tile using versa bond flex white mortar aka thinset right over the concrete.this type of thinset is designed to have a bit of flex to it to help with movement or cracking of tiles.  use 1/4 inch trowel,

Answer 6

i would mix thin set and put it down with 1/4 trowel and put the tiles right over the existing floor

why look for work plus if you raise the floor your gonna have to cut the door it might hit

Answer 7

everyone seems to have the right idea but you should really adress the crack why is it cracked is it bad is it going to get worse you should have a professional look at it and give you some answers befor you tile over it as the crack expands and contracts or shifts your tiles will also crack i would bet that they crack within six weeks if the concrete is not poperly preparedmaybe the backerboard isnt a bad idea and use the same mixture of mortar as you would for the tile good luck