Hi, I have a bathroom floor to tile, the only problem is, one half is tongue and groove timber and the other half is concrete, I suppose I could screw ply down over the entire floor, but I was wondering if some sort of a cement backer board would be better, has anyone had the same problem, idea's please.
Regards john at Tiling Plus (Elgin)

You could make sure boards are secure and ply over floorboards then self level the concrete to the same level leaving a 6mm gap which is known as a movement joint,this is silicone filled.USE 5MM spacers between tiles as this will make the joint not as noticeable.treat it as two floors and start with a full tile on either side of joint.Remember you will need two different types of adhesive.Hope this helps mate.

Good advice Bri,a 6mm backer board on the wood,screed concrete up to it with small expansion,2 part flexible adhesive on wood and standard rapid on the concrete.You need flexible grout on wood floor so therefore have to use the same all over the entire floor

You have been taught well and listened carefully, Use the same colour silicone as the grout you are using as well, just to add a bit to Brians post. Alternativly you could use hardibacker board from Topps, (cement partical board) 6mm thick

good advice there i couldnt agree more because if you tile over the meeting point the tiles will crack

i put a movement joint in a 42m floor last week after going to talk to darren to reasure myself i was doing it right i used granfix ultimate flex on timber part and bal rapid on concrete as it was porcelain then used grey bal superflx wide joint grout to fill the 5mm grout lines and unibond grey silicone from b&q for movement joint,when they both dry you can hardly tell the difference (the movement joint dictates where you start so you may have crap cuts around rest of room)

Originally Posted by guy1976

i put a movement joint in a 42m floor last week after going to talk to darren to reasure myself i was doing it right i used granfix ultimate flex on timber part and bal rapid on concrete as it was porcelain then used grey bal superflx wide joint grout to fill the 5mm grout lines and unibond grey silicone from b&q for movement joint,when they both dry you can hardly tell the difference (the movement joint dictates where you start so you may have crap cuts around rest of room)

great comments Guy and spot on,superflex is good on chipboard floorin and 2 part,but on t&g boards has to be standard wide joint grout with GT1 additive.

forgot to add the floor i done was 18mm mdf on timber part

2 part flexible on mdf and superflex grout is ok