underfloor heating......do I have a potential problem ?

[jonjo]

Probably only get worse to be honest yeah. Wrong adhesive would be something not flexible. Doesn't sound like it's just grout issue either. If the floor is huge and no expansion joints have been used you may get away with putting some in now. That's a long shot and it's only if that is actually the problem.

You shouldn't turn on the heating right after the tiling is done, it needs a couple of weeks to really cure before turning it on. And when you do turn it on you're meant to gradually build the heat up and then gradually turn it down each day so it's expanded and restracted to it's fullest extend. And only then should you use it as you would want to, on and off each day.

Screeds are out of my league but Dave's spot on with 'em. And we have a member on here who works for Lafarge and they're all about screeds! So I'm sure we'll be able to help find the issue, but I don't think we'll manage to stop you re-tiling it the right way and / or with the right gear.

Got any adhesive bags lying around somewhere still by chance?

its 100sqm in total and is in one continuous run (kitchen through hall to l/room into diner) all ditra matted which the tiler said expelled the need for expansion joints ??

it had about 2 weeks after tiling done until heating was turned on.

i burnt all the bags !! bugger.....i remember them being white and blue with coloured stripes in the corner or something like that

 

[DHTiling]

yes laid down and trowled came on a tipper lorry...put on the drive and barrowed it in

Ok Cement based screed, then your issue is more than likely a non-commissioned floor as Neale has stated .. This can cause thermal shock to the adhesive bed and this in turn can De-bond from the substrate,, so what you have is the matting floating in areas on the substrate.. this might not be any more now than this crunching sound you have..but it is still worth calling back your installer..

 

[Dan]

Not sure ditra eradicates the need for expansion joints does it?

 

[DHTiling]

Not really no.. so 100 mtrs in a run might just add way too much lateral stress..

 

[jonjo]

Ok Cement based screed, then your issue is more than likely a non-commissioned floor as Neale has stated .. This can cause thermal shock to the adhesive bed and this in turn can De-bond from the substrate,, so what you have is the matting floating in areas on the substrate.. this might not be any more now than this crunching sound you have..but it is still worth calling back your installer..

thanks Dave

will it get worse do you think ? why would it de bond...wrong bond or ??

so your saying the ditra matting is not stuck to the screed properly ?

 

[DHTiling]

Too much lateral stress..( side ways movement) can cause them to heave.. are the loose ones or this creaking area towards the middle of the floor..?

 

[jonjo]

Not really no.. so 100 mtrs in a run might just add way too much lateral stress..

sorry if im not on topic here but its 100sqm accrued in 4 seperate areas but all are flowing into each other if you get me

 

[jonjo]

Too much lateral stress..( side ways movement) can cause them to heave.. are the loose ones or this creaking area towards the middle of the floor..?

no they seem to be here there and everywhere...no real pattern

 

[DHTiling]

So.. what is the largest separate area..? and i take it is doorways separating,.

 

[Dan]

You need expansion joints where different rooms meet, every 10 meters on large floors in length and width, and even if the rooms are knocked through, I'd still have one somewhere for the sake of each end of the room having slightly different heat-up and cool-down times due to all sorts of factors, oven at one end, patio doors at the other for example.