A little advice would be greatly appreciated....

I recently started my first DIY tiling job - doing my dining room floor with standard ceramic floor tiles.

It seemed to all go smoothly, good cuts and an even lay but after I had grouted it a couple of days later I realised that some of the tiles were loose and that the grout was cracking.

The surface that I was laying onto was thick weyrock floor board on a cement foundation and the adhesive that I used was recommended by the tile stockict - flexible due to the wooden floor boards.

I have had enough at looking at my failed attempt and would now like to redo the entire job - but am stuck as to what I did wrong in the first place??

how solid was the floor when you tiled it ......if you jump on the floor is there much bounce .....and what make was the adhesive

Did you tile directly onto the floor...? What prep did you do?

As above and was the adhesive ready mixed, or a powdered one that you add water to and mix yourself? Welcome along to the forum.

sounds like movement in the floor .

sounds like a floating floor. the adhesive should have been a 2 part flexible, although most tilers wouldn't tile on a floating floor as there is far too much flex in it, also the floor should have been overboarded as tiling directly on chipboard is a 'no-no'

As above, to much deflection imosorry.

Thanks for the quick responses lads - greatly appreciated - I sealed the floor with tilers primer then tiled directly onto the weyrock.

Forgotten the name of the adhesive but it was a powdered version that I mixed myself.

In terms of the bounce of the floor - the dining room is a newly built extension with a concrete floor and large floor board sections set on top to bring it in line with the rest of the house.

Can't remember any flex in it - my first thought was that I mixed the adhesive wrong so I went out and bought some B&Q ready made stuff. Lifted the tiles that were loose and re-fixed them. But time has gone by and all of the tiles that are in the main walk way that is used on a daily basis have had the grout around them crack.

was the primer P.V.A........the B&Q ready mixed stuff is pants

floating floor or not weyroc boards are not suitable to tile on

I think it was P.V.A based - I mixed a couple of parts of it with water and painted it over the area - I purchased it from a discount tiles store after I quizzed them as to what I needed.

Firstly, weyroc is unsuitable to tile directly to.
Pva based primers are unsuitable for tiling.
It also sounds like you have a floating floor, which the majority of pro tilers will refuse to tile on.

You need to strip floor to start with, then find out if the floor is floating or not.

I can remember the builder fixing the boards straight to the cement foundations ??

To a screed floor or concrete, could be absorbing moisture from the floor.

I think it was a solid concrete foundation and he put a membrane down and screed it - then placed the boards over it. Do you think it would be best boarding out the whole area? If so that boarding / thickness would you suggest? And what adhesive & grout?

It was a concrete foundation and I seem to remember him laying down a membrane and screed then fixing the boards to this base.

Would you suggest boarding out the whole area? if so what boarding would be best and what addy/grout combination?

why did he put board on the screed? why not just screed to the right level?

haven't the foggiest - wasn't into DIY at the time so just let him get on with it

Hi Andy,
Mapei technical advise that using P.V.A can sometimes have the adverse effect with adhesive and refer the cement-based adhesive back to a liquid state (although cases of this are rarely heard of), a recommended 'Primer G' from most Mapei suppliers. Going by what you've mentioned it could be one of many situations, and so stripping it and starting from scratch will ultimately be the best option. If it was movement within the floorboards itself then most likely the tiles and/or grout will break in correlation to the joints. If not it could be the case of either the adhesive or floor not bonding together sufficiently. Either way my best advice is to lift the tiles and investigate before the situation deteriorates!
The benefit of using powdered grout is that it comes with the additives of flexibility, waterproof and the fight against blackspot and mould.

Hope this helps!

Hi TileGiant Macc - thanks for the advice - would you suggest priming the area in a different way or boarding over the area - if boarding is the best way how do I go about this?

Hi Andy,
Which adhesive product did you use?

I really can't remember - a powder adhesive bought from a discout tiles store - was recommended as the best one for wooden surfaces.

Hi Andy,
Best advice is to get it all up and start again. It could be that the wood is contracting and expanding with heat or even moisture, or it could just be dry flakey grout. There are cases where grout cracks on solid floors. If you're not pleased with the tiling and have a spare weekend.....

regarding the substrate, you say it's concrete, are you sure it's not bison beam construction? (beams and blocks over the hollow floor then insulation and floor boards)

Thanks for all the advice lads - going to take it all up and give it another go

Really appreciate all the pointers