Floor creaking under tiles in new bathroom, is it a problem ?

aidancoughlan

I had a bathroom renovated recently. I had researched what was considered best practices for tiling over floorboards - and was considering cement boards, or removing the floor and laying down a new 22mm WBP Plywood floor, but the tiler convinced me that laying half-inch/12mm ply down over the floorboards screwed down well & with decoupling membrane on top would be better on the basis that disturbing the existing floor and getting a new floor down & out under the edges would be awkward.
Overall, the job is a good one, with a good finish - but we have slight (intermittent) creaking under the tiles in one area of the floor, near the shower tray entrance.

My first question is, how likely is it that this will develop into a real problem ? The grout hasn't cracked (yet!), and the movement is small enough that there does not appear to be any visual flexing going on - only creaking nose, which is intermittent (sometimes it doesn't happen at all). Is this likely just some settling of the new ply subfloor underneath ?

My second question is ... is there a solution, and what would it involve - is it unreasonable to expect them to take up some of the tiles in the most affected area and screwing the ply down tighter with more screws ? The problem happens most at the joint between the floor and the shower tray - is removing the shower tray and refitting a big job if it's necessary?

Sleeper12

Sounds to me like the tiler did a great job.

It could be the joists under the floor moving slightly.
The plumber who fitted the tray possibly took lumps out of the floor for the waste.
Remember the tiler would have used floor tile flexible adhesive. It allows for slight movement in the floor.
Hard to be 100% certain without seeing it but I'd say you have nothing to worry about.

mick121

Tiler was correct once he used plenty of screws

sky6

It sounds like your Tiler done a decent job. The problem when working with timbers is you can never be certain that you've cured every Creak. It could even be the added weight of the Tiles exacerbates the problem.
Depending where the Waste on the Shower is located in relation to the problem you might be able to remove the shower waste from the tray and spray expandable foam using a hose into the area to provide a little more support to the timbers. Thereby eliminating the squeak.

aidancoughlan

Thanks guys, seems like general consensus is that it sounds allright . it's only occasional creaking so hopefully won't be a problem.