Probs with tiles over UFH. .

[slikt]

Hi Gents,

I've just finished a small bathroom job 2000x2000mm and basically, all the grout has cracked and the adhesive has cracked away from the floor, I know this as i can see the crack at the door edge as its waiting for carpet, its been laid on a floating floor, I primed the floor and laid the UFH and used a good bed of adhesive, laid the tiles and the floor had no foot traffic for over 24hrs, then grouted, again no foot traffic for over 24hrs, its been a week and i've gone back to the job and at least 50% has cracked, also it feels like the floor the UFH has still to be used. I dont understand as the adhesive and grout is for wooden floors and flexible. I've laid a good few floors and never had this problem, I have to say I usually use BAL and i've tried a new adhesive (will get the name in the morning). Any prof ideas as it looks like its all gotta be done again...!!

[diamondtiling]

What was the makeup of the floor? Floating floors are always going to present problems.

[whitebeam]

Floating floor could be the problem because it's floating.

What was the boarding on the floor, ply etc

[slikt]

What was the makeup of the floor? Floating floors are always going to present problems.

Particle board over 2in polystyrene. i've laid over this type of floor before with BAL adhesive and Slate, with no probs, just gutted as the bathroom is now all finished and its been a total refurb, think its the adhesive as its supposed to be the best gear for this job (so the tiling shop told me) but its crumbled out the old bucket when it was dry??? Hmmmmm . .

[diamondtiling]

Something must have been fundamentally wrong with the floor for all these cracks to appear so quickly, What was the adhesive you used? It would help us to know that.

[slikt]

Something must have been fundamentally wrong with the floor for all these cracks to appear so quickly, What was the adhesive you used? It would help us to know that.

Thats what i'm thinking as i'm not a total novice with tiling, I will get the name of the adhesive tomorrow as i'm back at the job in the morning, you guys will know whether its good or bad.

I always work the grout in well, so i'm very confused why its cracked so soon. Thanks for your replies so far guys.

[timeless john]

The question remains - did you cover he particle boards with plywood/hardie backer board etc. before you laid the underfloor heating mats.
What did you prime the floor with prior to laying the UFH.

[Dave]

Missing the point here..??.. It is a floating floor and they are highly prone to excessive deflection and adding ufh as well then you are asking for a failure.

So this is really a fixer error.

[Colour Republic]

I read this thread a couple of minutes ago and thought to myself "wait till Dave sees the words 'floating floor' "

that said has this floor cracked without any foot traffic apart from when you grouted? or was it in use by the customer the day after you grouted?

i.e it's cracked without anybody being near it or there is so much deflection in the floor it has cracked instantly on contact?

[doug boardley]

floaters..... the word says it all

[diamondtiling]

A song for the floaters

[ame=http://www.youtube.com/watch?v=gT_9OUvmb5I]YouTube - the floaters - float on[/ame]

[slikt]

A song for the floaters

YouTube - the floaters - float on

Haha. . love it. .

[slikt]

I read this thread a couple of minutes ago and thought to myself "wait till Dave sees the words 'floating floor' "

that said has this floor cracked without any foot traffic apart from when you grouted? or was it in use by the customer the day after you grouted?

i.e it's cracked without anybody being near it or there is so much deflection in the floor it has cracked instantly on contact?

I think the guy used it once I went home and turned the heating on too soon as I questioned him today and he was quite dismissive about it all as I said i'd do it all again for him and waive the labour costs as he is a bit of a stickler and wanted me to use all the materials that he bought, plus he doesnt like being told anything (the guy is 71 and an ex builder) so I just did as i'm told. I wont be doing that again, it'll be my way or the highway. .

[slikt]

The question remains - did you cover he particle boards with plywood/hardie backer board etc. before you laid the underfloor heating mats.
What did you prime the floor with prior to laying the UFH.

I didnt use backer board as I thought the floor was sound enough and I used 'palace tilers primer' on the floor before I put the UFH down. Will defo use backer board next time.