Tiling sub floor

Hi, yes you can install cement backer boards directly onto the floorboards without the need for a plywood subfloor. The cement board adhesive should be used and then screwed down.

Hi. It can be done but you would need adhesive under the cement boards to hold down the board and to prevent movements in the floor. Putting adhesie under the cement board will dampen the noise. And you need to screw down the cement board also but be carefI'll not to use too long screws as water pipes might be under the floor board. The best options is using Ditra Matt on floor boards as this is more flexible and and really hold unto the floor and dampens the floor from noise. The third option is putting down ply board and also laying the Ditra Mat unto the ply board and then tile unto the Dotra Matt if you want a super noise sound proof floor especially if it's a upstairs floor. So yes you can put down option One but you will need to use a tile trowel to scrape the adhesive unto to floor board and screw down the board. Let the two boards dry first with the adhesive before you lay your 60x30 tiles Donovan

To fit hardy backer or cement boards to floor boards you should use minium thickness of 10 mm boards, Also they should be fixed with adhesive and screwed every 300 mm, It is also best to make sure that all floor boards are flat and screwed securely prior to fixing.

I wouldn't use plaster boards on any floor as water may get under the tiles and this would rot the board in time meaning the floor would probably break up. There are other options to look at which a tiler would inform the client.