Tiling on a suspended floor

[mikethetile]

Mike, thanks - i'll look into it. Will probably go with the retiling still as most of the tiles will be reuable and I like them. Have to see how we can best do this and if the builder will actually come back.

Dave - could you please recommend someone in the SW London area to do an inspection?

Many thanks
Sukie

very wise Sukie

im pleased your still thinking of tiles, the other options are ok but its not what you wanted and no where near as hardwearing in a kitchen as tiles

 

[Sukie666]

Doug, when they fixed a row of 8 tiles last month we only lost one tile - the one they had to crack. With the rest, the adhesive did NOT stick to the back of the tiles. No cleaning was required. The adhesive bearly stuck to the plywood either. I just used my hand to gently push it and it came unstuck. No tools required. I captured this on my phone if you would like a look. Did the adhesive dry too fast? We only gave it about a week before the ufh was turned on. The builders told me a couple of day was sufficient. I now know it should have been at least two weeks.

 

[doug boardley]

my mistake Sukie, if they'd been stuck down correctly, it would have been a beggar to clean them, I should've said:smilewinkgrin:

 

[mikethetile]

ive a feeling they used dispersion as they are obviously clueless when it comes to tiling:yikes:

 

[Ceramico tiling]

I dont know the correct way but what if you just strengthened the floor as best u can for vertical deflection,maybe with 18mm ply and then then another layer diagonally covering all joints of previous layer(screwed and pva).then ditra ontop.?

 

[Sukie666]

That was a consideration but with a wet ufh system, blindly screwing down the layers of plywood would be asking for trouble. If there was something I could use to glue cross ply that would be better.

 

[mikethetile]

no it wouldnt brace the floor, it would still deflect

 

[DHTiling]

Mike, thanks - i'll look into it. Will probably go with the retiling still as most of the tiles will be reuable and I like them. Have to see how we can best do this and if the builder will actually come back.

Dave - could you please recommend someone in the SW London area to do an inspection?

Many thanks
Sukie

Sorry just seen this.. will ask someone in your area to contact you.

 

[Time's Ran Out]

Without seeing the results of the tiles that were refixed by your builder I would have to question the total load on your suspended floor. A central island with a large weight of worktop will have a considerable effect on the deflection issue. Did your builder or kitchen company supply you with the relevant weight and required support figures and was a structural surveyor consulted.
Although you certainly have a issue with the method of fixing and preparation for the tiling, retiling with additional support may not be a satisfactory answer to another problem.

 

[diamondtiling]

I dont know the correct way but what if you just strengthened the floor as best u can for vertical deflection,maybe with 18mm ply and then then another layer diagonally covering all joints of previous layer(screwed and pva).then ditra ontop.?

Dont use pva.

 

[Sukie666]

Hi John, the kitchen company did not supply any calculations. I don't remember if they ask about the floor at all. They are a reputable company and delivered Imo a very good level of service so I have never questioned this. The builder who did the flooring was also used for removing a supporting wall to open up the kitchen into the dinning room. The island is basically where the supporting wall was before. A structural engineer did the calculation for the steel beam only. I wasn't aware nor informed by the builder that additional calculations were required. The builder also fitted the kitchen units.
What do you suggest I do now?
Thanks

 

[Scott]

Just read this from start to finish and must have missed this thread!

Dom, i think Russ is refering to using the PVA between the sheets of ply and not on the top

Sukie, if the joists are supported on brick piers under the floor and there is still vertical deflection then it may be possible to add in additional support between the piers and the joists to pack them up. Is there a large void under the floor? Typically houses of these era did have large voids so tt may be possible to access the underside of the floor from a different room? The noggins could also be added in this way.

TimelessJohns comments are valid point but there isnt a set requirement for any calculations for building regs for this, so no one has missed anything out. TJ is very good at seeing things from a different angle to a lot of us and when you think about it, it makes sense for it to have been taken into account. Although with a largge weight in the midle of the floor this should have cured some of the deflection to a certain degree. Sadly what that degree is i dont know

 

[Time's Ran Out]

Re reading the facts as printed it would seem as though the tiles have not stuck to the plywood. It could be due to the pva adhesive,the adhesive type, dust on floor/back of tile and certainly the dot and dab method of fixing. If it is only 18mm plywood fixed direct to the joists and tiled direct to this - as previously stated - a deflection issue may be the cause. Is there any cracks appearing at 120cm widths or just loose tiles and is the grout cracking out of the joints?
My earlier post was just concerned that the weight of the new kitchen/worktops had increased the movement in the floor and has the area of supported wall removal been adequately reinforced to hold the central island.
Following Daves advice I would certainly request a site visit by an experienced tiling contractor and he /she may be able to confirm some of the issues you may face.
Your builder -the main contractor- is the person with the answers so I'd ask him if he is a member of a Building Federation so you may be able to ask their advice:smilewinkgrin:

 

[Sukie666]

Scottey, better late than never!
The void is about 60-70cm off the ground only. What is considered adequate?

TJ - there are no cracks in the tiles. In many places, the grout has cracked or seem to be stuck to one side only. I DON'T ' think the grout (Mapei utracolor plus) was a flexible one so this is expected given flexing in the floor. In some area its whole groups of tiles together - in others 120-180cms width.

Looking at some pictures, it seems to me the tiles that have lifted the most have been where two sheets of plys meet. It seems to affect the whole row of tile. Tiles adjacent to these are less affected.

Thanks
Sukie

 

[Scott]

Thats plenty large enough to get under the floor, not the nicest place to be ill admit but if it gets the job done. As long as you have somewhere to get under it of course!