I am in dispute with some monkeys who tiled my bathroom using 34x25 cm ceramic tiles on new very smooth 2 days old gypsum plaster, with Bal White Star and Topps Trade Rapidset adhesives. They did not use primer, despite having written in a letter that they used Bal Primer. Am I right to think that the Topps adhesive is cement based, and hence that ettringite crystals will form? Am I also right to think that the suction of the wall will cause the adhesives to dry too quickly, before they can soak into the wall? If so, is there an authoritative book, or manual, which contains this information? I am writing a document that will go to court, and it needs to be accurate. Thus quoting my mate Pete, or whoever, is not enough, but a respected book should suffice, and hopefully Topps customer services can also confirm the cement based part. The monkeys posted a response to my damning review on CheckATrade. They stated that according to the datasheet, the Topps adhesive does not require primer. That contradicts the packet, but the Topps shop did not have datasheets.

Also, does anyone in the Hindhead/Alton area have an old empty green packet of Topps Trade Rapidset adhesive. I would buy it from them for £5! And I would collect. Money for rubbish! This would be used as evidence, as the replacement fitters threw away the old packet from the monkeys, which I had saved. Fnnarrr.

welcome!

Primer isn't needed for white star as it is acrylic based and self priming but the plaster should have been left a minimum of 4 weeks, if they have used the cement based on the plaster as well then this should have been primed

Self priming dispersion adhesive.

If the adhesive was tubbed then as long as the substrate was brushed to remove dust , then no primer is required on gypsum skim coat.

If the adhesive was powdered cement based then yes you need a suitable primer.

Bs5385 covers this.

and a very Merry Xmas.

as Dave BS 5385 covers all things pertaining to all tiling related matters. Failing that The Tile Association (TTA) would offer some advice. Merry Christmas.

Thank you. The British Standard could be exactly what I need, although it does look expensive. Gulp. It sounds like a trip to Foyles in London is in order.

Topps adhesive should have a technical literature

Originally Posted by pjc

Topps adhesive should have a technical literature

One of their staff promised to send me some literature. I was also able to buy a bag of adhesive (with a small split) at cost price thanks to a generous and trusting staff member. And the bag confirms that it is cement based.