Tiling Standards blob or full bed? Help

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deema

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I’ve a problem, which could be a big problem! I’ve had a few bathrooms tiled with large tiles that weigh circa 17+KG / m2. I think the British standard for tiling require wall tiles to have full bed adhesion rather than the blob method if the tiles exceed 70% of the weight bearing capability of the substrate (but I could be just dreaming)? If this is the case, can anyone point me in the right direction to which standards apply and if possible a summary of what the requirements are. I also have a feeling that full adhesion is required for fire regs? Again, I think I read this somewhere but it may not be applicable to the UK?

The tiles are in bathrooms, which is plaster boarded, it’s a retro fit. The shower areas have been tanked, but not the rest of the room, again, I seem to think that the new standards require damp rooms to be fully tanked before tiling?

Anyway, one of the bathrooms the tiles are now loose / falling off before they’ve got to grouting…..so at least it’s been found early. I had been assured they were all full bed tiled…..but the evidence is in, and they aren’t!

IMG_2872.jpeg
 
for tiling require wall tiles to have full bed adhesion rather than the blob method if the tiles exceed 70% of the weight bearing capability of the substrate (but I could be just dreaming)?
When I last had a tiler in just over a year ago for bathroom floor and wall tiles he said no one blobs anymore and always use full bed. With large tiles you also need tile leveling clips and wedges like these https://www.protilertools.co.uk/cat...g-systems---spacers/tile-levelling-clips/rubi
 
Don't know the rules and regs but I have always used full bed on walls and floors, those are fairly hefty lumps so i reckon full bed and you should be stuck for life :)
 
That is just p!ss poor workmanship, presumably the lot has got to come off, before they fall off! looks like the adhesive just pulled of the paint, I'd question as to whether was the wall treated/primed in the first place.

Not the best instructions, but this how we would do large format tiles: Tiling we also use the LASH spacers, which look as if they had anyway.

There are standards I found but I can only quote the references:

British Standards
The relevant British Standards for tiling are the following:

BS 5385-3:2007 – Wall and floor tiling – Part 3: Design and installation of internal and external ceramic and mosaic floor tiling in normal conditions – Code of practice

BS 5385-1:2009 – Wall and floor tiling – Part 1: Design and installation of ceramic, natural stone and mosaic wall tiling in normal internal conditions – Code of practice

Grouting is covered by British Standard BS EN 13888.
 
I’ve never used blobs for tiles and funnily enough I’ve never had to go back to a complaint that tiles have fallen off the walls either. My personal opinion of blobs is they are pointless as it leaves multiple voids behind the tiles. This method may of worked with 4” tiles but with modern trends of tiles in excess of 600mm long blobs are not fit for purpose.. I’m not aware of the regs but I just use common sense. Interesting to note that every failed patio I’ve ever replaced was laid on cement blobs - full of voids for water to collect and freeze in winter and expand and eventually sink . I always use the appropriate primer or sealer to suit the existing surface and the type of tiles being used ..
 
That's shocking. There is a difference between full bed (100% coverage/contact) and normal combed tile cement which gives a bit less than 100% contact depending on the size of the comb, flatness of surface, etc, but large format wall tiles on blobs like that is full-on cowboy with boots, hat, chaps and stirrups.
 
Not to drag the thread off topic but I'm aware of both solid cement board like Hardiebacker and Jackoboard style with a foam core between two cement skins. Which is better for a bathroom refit like this one and why ?
 
Interestingly looking at the tiles below the removed area it appears they have been bedded in ribbed adhesive spread on the walls, makes you wonder if someone who didn’t know what they were doing finished off the top bit.
Be interesting to know what adhesive was used for the dabbed area, from the looks of how they’ve come off it could well have been a premixed adhesive which of course on those size tile is inappropriate
 
To be fair, it appears that the adhesive blobs have not let go of either the tiles or the paint. It's the paint that has peeled off the walls, so a 'full bed' would simply rip all the paint off.
Is it possible that this bathroom was previously tiled half way up with paint above and it's only the painted part that's going to be the problem?
 
it appears that the adhesive blobs have not let go of either the tiles or the paint. It's the paint that has peeled off the walls
If that is the case then it is simply down to bad workmanship, we all know that preparation is an important part of most jobs and you would not just paint over paint that has not been preped so why tile onto un preped walls .
 
Interesting to note that the blobs get smaller at the top - as if the tiler was trying to make the adhesive stretch to finish the job.
 
Interesting to note that the blobs get smaller at the top - as if the tiler was trying to make the adhesive stretch to finish the job.
Interesting observation, there is a lot of adhesive available (there is a lot more tiling to do) , it could be that he didn’t want to mix up another bucket full and it was the end of the day.
 
The bathroom had toughened safety glass panels around the shower area and splash backs (I thought it was just shower board until I took them out!) and the rest was painted walls. It’s a very valid and interesting point that it’s the paint that’s peeling.
 
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hence the need for all loose material inc paint to be removed and a suitable primer/ sealer applied. A lot of talk regarding pva but this is generally not suitable for tiling as you can end up with a similar situation. As said above if you paint new gloss onto old gloss without providing a key into the existing paint then it will peel . There is no excuse for shoddy work like this unless the tiler just didn’t have a clue or simply couldn’t give a xxxx . If I get a job and I’ve not fitted ghat type of tile before then I educate myself, speak to professional tilers at the tile company,s etc and basically do my homework. If I’m still not confident in taking on the job then I’ll simply decline it . Sounds like the usual I’ll do the job with the minimum of materials or understanding of the environment but I’ll charge you the maximum amount I can get away with. I guess the money is more important to some who have lowest possible standards and integrity.
 
I tiled a lot of walls when I had the business and have seen this many times. Very poor work at best and a rip off at worst especially when they assured you the tiles were on a full adhesive bed.
No excuses possible they need to be taken to task and the tiles removed and correctly fixed on properly prepared surface
 
Thanks guys, been through it today with primary contractor. Dot and dab tiles all coming off, surface being properly prepared and full bed adhesive for retiling. The upside is we can save the tiles…..they are coming off quickly and easily🥴
 
Not to drag the thread off topic but I'm aware of both solid cement board like Hardiebacker and Jackoboard style with a foam core between two cement skins. Which is better for a bathroom refit like this one and why ?
I cannot say if these are better but Ive now used both the Foam core board and the cement board and the Foam is a delight to work with, easy to cut and has a course mesh finish that Im sure would be very grippy, the downside is having to use special thin flat washers and stainless screws.
The Cement board is more difficult to cut even with the correct scribing tool, but regular passivated I think,CS screws can be used,,Im assured that these should not rust but check out forums about this before commiting yourself, likewise a good surface for tiling and some come pre coated with a sealer and can be bought a bit cheaper. If I was doing a shower for myself I would certainly use one of these 2 types of boards.
 

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