Tubbed Addy - TilersForums.co.uk | Tile Forums

CUSH68 · 15-05-2008

Hi all,

Question about tubbed stuff.

Was on a bathrom job recently with ceramic tiles ( 330 x 250 )on plasterboard,
and was supplied with dispersion addy. Checked a few as I went for coverage etc and that seemed fine. Ended up one tile short (customer supplied) and decided to removng one that would be covered by a vanity unit.
This was maybe 2 hrs into the fix, and managed to remove single tle easily.
I know this addy takes a while to dry out but what worried me was that the previous coverage on back of tile was now not there.
100% addy on wall with the none on tile back. marks from back of tile were visible in the addy, so was definately embeded well. Is this normal,as in does it take a while for addy to bite into the tile?

Thanks

Mark

Turkish · 15-05-2008

I think dispersion stuff takes around 16 hours to set hard mate so wouldn`t be too worried if it was a decent make of adhesive. I would use Bal white star on that, bloody good stuff!

Turkish

**dock** · 15-05-2008

Hi Cush
The bond development of ready mixed adhesives occurs as water dries out and the co-polymer within the adhesive starts to polymerise. In the early part of this process the polymer "film forms" and the water is absorbed by the background substrate and the tile. Cohesive strength develops and if the background is more porous than the tile then forcible removal of the tile will cause separation at the weakest interface which could well be between the tile and the adhesive, particularly if the adhesive used contains alot of additives to help with the non slip characteristics. At the next stage a "crust" develops around the periphery of each tile and it can be "some time" before the adhesive dries fully. This can be further extended if the joints are grouted before the adhesive has fully set.

It is for this reason that larger tiles such as the ones you describe are normally fixed in a cement based adhesive. These type of adhesives use a significant amount of water to chemically alter the cement therefore they do not need to lose water to develop their adhesion.

Hope this helps

dock

CUSH68 · 15-05-2008

That certainly answers my question.

Thanks guys.

What would be the maximum advisable tile size for dispersion adhesive use?
Customer was informed that these were not classed as large format tiles,and supplied with the tubs.
As a preference I would prefer to use bagged addy anyway.
Thanks again for the quick replies.

Mark

**Fekin** · 15-05-2008

330 x 250 are fine for tubbed adhesive, once you break the barrier like 333 x 333 then I always switch to cement.

**dock** · 15-05-2008

Thats always a difficult one and very much dependant on the porosity of the background and the tile.

Peoples views vary considerably and it also depends on the quality of the adhesive you use but....................

I guess as a general rule ready mixed.................max around 250 x 200mm

dock

CUSH68 · 15-05-2008

Thanks to all for replies.

Great info as always.

Mark

**Fekin** · 15-05-2008

Quote:

Originally Posted by dock

Thats always a difficult one and very much dependant on the porosity of the background and the tile.

Peoples views vary considerably and it also depends on the quality of the adhesive you use but....................

I guess as a general rule ready mixed.................max around 250 x 200mm

dock

Depends on tile thickness too.

I would only go upto 333 x 333 if they were 6mm, 10mm then cement without a second thought, but use a good tubbed addy on a 6mm thick 333 ceramic and it will be fine, but as I said, that's the max I would work upto with tubbed.