Tiling on a suspended floor

[doug boardley]

you misunderstand me Sukie, ditra is worth putting down, but in your situation I feel the installation would have failed anyway due to what appears to be vertical deflection and poor fixing practice.

 

[mikethetile]

joists laid @ 12" centres on brick sleepers wont usually deflect and even with only 6x2 for joists the close spacing makes up for it, my downstairs floors are exactly the same consruction and dont deflect at all

if your having the builders back to rectify then dougs advice on using 25mm wbp would be wise as they used pva to seal the boards which is incorrect and the 18mm are now useless

while they have the boards up they could add noggins to brace the floor, they should be able to do this without disturbing the ufh

talk to your builders and see what you can do with them, if no joy stay on here for support

with the issue of replacing the tiles, all tiles ned to come up and be replaced as they are incorrectly fixed, I realise this entails removing the kitchen but they will have to bite the bullet and put it right and get real tilers in next time

 

[Sukie666]

I see Doug, so if they screw it down properly, use the ditra mat and correct adhesive and primer (BAL?) and apply it properly that should give a better fighting chance?

thanks

 

[doug boardley]

it should do Sukie, altho' Bal is very good it is also very expensive compared to comparable quality adhesives such as Mapei Keraquick used with Primer G.

 

[Sukie666]

Twice the price of the Tilemasters adhesive in fact! But, a number of the ebuild forum members recommended it along with the Tiling Association. I would much rather pay more than have to do this again.

With the ditra matting, is there anything particular I should be aware of or any 'No no!' to keep in mind?

thanks

 

[paul flight]

doug is right . get hold of the builder tell him what you want done at no cost to you . if he is any good he will do this work . tell him you want a experienced tiler to do the work. you have paid a lot for this to be right.! be strong and dont take no for a answer .. in fact put it in writing to him so that he knows that you have done your home work on this on .. which he did not.

 

[Sukie666]

Mikethetile - don't think we can go for the 25mm unless we take the kitchen apart. What is the purpose of the noggins and do they sit on the joist?
thanks

 

[mikethetile]

they sit between the joists and prevent sideways movement

you cut 6x2 to fit tightly between the joists and fix them in a row, you then wedge at either end between wall and joist,this takes all the spring out of the floor

the kitchen will need to be removed to do this work

theres no point in tiling over boards that have been sealed with pva as the water in the adhesive reactivates the pva preventing the adhesive from bonding to the substrate, one option if there is no deflection in the floor is to stick and mechanicly fix backer board to the ply and tile on that, this will raise the floor by about 6mm

the issue with that is if theres any deflection in the floor. try bouncing in the middle of the floor on the balls of your feet and see if you can feel any bounce or give

 

[grumpygrouter]

Just as an aside to previous advice, if you go down the route of using BAL adhesives on to the ply then BAL DO NOT recommend priming the tiling face of the ply and if you do it would invalidate their warranty (which isn't up to much for domestics anyway!)

 

[DHTiling]

Hi..

Sorry you have such a bad installation..

You would be wise to get an independent assessment of the job in hand.

The builders have not followed uk standards BS 5385 and the fixing method is totally wrong..

You are not in the wrong here and should not be paying for extra tiles or materials .

IMO all the tiles will eventually fail due the method and prep used... you did the right thing coming to a tiling forum rather than ebuild as we specialise in this sort of advice.

PVA is not a recognised primer for tiling and really on that spec of timber floor an S2 highly flexible adhesive should have been used.

Please contact the builder ASAP and stress your concerns highly... but an independent report will back your concerns up..