My contractor laid Durock cement board in the 2nd floor bathroom for flooring. But some tile person told me that Durock is good for wall use, not good for walking on for large area second floor. We also feel it is not dense or sturdy enough while walking.

Should we change to Hardie Backboard or put one more thin layer of cement on top of the Durock board? Also should nails be used or screws?

Thank you

depends on thickness of board and condition of subfloor

use screws

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"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638

3/4" sub-floor and 1/2" durock underlayment should be solid as a rock.

Backerboard, be it Durock, Wonderboard or Hardi are not designed to strengthen/stiffen the floor. They are only for providing a surface to tile on. The joist size/spacing and thickness of the subfloor is what matters for strength/stiffness. How stiff the floor needs to be depends on type and size of the tile.

I was taught that the combined thickness of the sub-floor and underlayment needs to be at least 1 1/4". I have never seen anything other than 3/4 t&g used as sub-floor, and I don't care if you spaced your joists 6" OC, with 3/4" sub, you'll crack any tile you put down.

Durorock and Hardie are brand names for concrete board which is just FINE for your tile
What is important is whether the substrate is adequate and the concrete board will likely state that the board be set in thinset Follow directions
Also I use the waffel pattern roll Germany bright orange cut with razor knife for best application but if you use this product a common mistake is to set tile with the wrong thinset as there is no downward moisture evaporation the floor is sealed so do not use modified thinset to set tile over this matting
Hope this hepls

I am a profesional tile installer who is taking a minute to tell you how it should be done! If going over a wood subfloor then use water resistant paper then nail, staple,or screw.( roofing staples or nails plus a few screws) Expanded wire mesh or Lathe followed by a skim coat of thinset. This will provide the best substrate for which you can begin to tile when dry.



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