Help!: raised timber floor

[pursedog]

what would you guys recommend to use on a raised timber floor before tiling.
last year when i first started i didnt use anything and very soon after the grout cracked and i was called back to repair it..over and over again.

now have a 25m2 kitchen to do. the floor boards are raised on joists.
wont make the same mistake again but the customer is looking at a fair few quid to prepare the floor before i even lay a tile.

i gather my options are backerboard which is easy to use, effective but costly or 18mm ply.

any advice?

[Dave]

What condition are the floorboards in.....just you saying the floor needs a fair few quid to prep it....

[pursedog]

dont know what condition they are in yet as they have a laminate floor on it at the moment. they have the flooring exposed in other rooms as they are doing quite a bit of work and it looks ok in there.
i have been told that the hardibacker boards will decrease the 'bounce' in the floor. dont get me wrong the floor is not like a trampoline but i dont want a repeat with what happened before on the other job.
ive calculated that materials alone to give me a suitable surface will be about £350-£400 including labour taking up old flooring.

[grumpygrouter]

By the sound of it with bounce in 25m2 the best option will be the ply. It is quite a large area and backer board doesn't add strength.

[pursedog]

what thickness of ply? baring in mind the added height.

[grumpygrouter]

For strengthening BS states 15mm but that isn't available so it would need to be 18mm. What tiles are you laying?

[pursedog]

the client wants quarry tiles. they have not been purchased yet but if i ply and use these then the height difference to the next room will be massive.
ive explained this so its in their hands now.
its a tricky one but if they want the job to look good then theres no other way.

[smurf21]

with that weight stick to your guns or walk... 18 mm and fsst flex....

[bigneil]

the client wants quarry tiles. they have not been purchased yet but if i ply and use these then the height difference to the next room will be massive.
ive explained this so its in their hands now.
its a tricky one but if they want the job to look good then theres no other way.

If there is going to be a prominent height difference then suggest that they get a hefty wooden Threshold fitted, and cut the door to fit accordingly.

[pursedog]

i spoke with an experienced tiler friend today and he said to use 18mm marine ply. looked it up and is well expensive. what ply would you guys recommend?

[whitebeam]

They want the job done mate then their going to have pay for it, Quarrys look awful if the floor is all over the place, 18mm is the only way to go IMO As big neil says get a good solid threshhold

[grumpygrouter]

WBP ply will be fine. Much cheaper than Marine!

[muffinman]

BS is 18mm now