Tiling on to bonding

[Rived36]

new to this forum,
Just wondering if any of you guys can give me any advice on a job im about to start,
After a few years in the maintenance sector (plumbing) im going self employed back into bathrooms like i did many moons ago, so far its hoing really well but i am having concernes over this one,
Got my plasterer coming in tomorrow after ive finished smashing all the old tiles off the wall,
He's constantly telling me "ill bond it, you can tile onto bonding ive done it for loads of tilers, you just need to pva it"
Ive always had the rooms skimmed out then pva'd the room out
Is he talking pony or what?
Last thing i want is things going the way of the pear !
Thanks in advance

 

[One Day]

The problem with bonding is it's very weak compared to tile adhesive. Ok, so you can address the fact that it's super porous by priming it several times, not with pva of course. But tile adhesive as it sets can literally tear bonding apart.
Personally, I try never to tile onto anything containing gypsum but you definitely shouldn't be tiling into bonding.

 

[Qwerty]

+1

 

[Andy Allen]

And you definitely shouldn't be using PVA....

 

[Dumbo]

If you speak to adhesive manufacturer's they will not recommend tiling to bonding as it i 1part of a 2 part system . That is the second part being skim coat .

 

[WetSaw]

If you've got enough space for a coat of bonding you've usually got enough space to d&d board. Saves money and time on the plasterer plus you can get the wall flat and plumb!

 

[Rived36]

If you've got enough space for a coat of bonding you've usually got enough space to d&d board. Saves money and time on the plasterer plus you can get the wall flat and plumb!

This is another point ive heard lots of discussions about,
im not a tiler im a bathroom fitter so all advice is welcome really but ive heard it said many a time that even if dot n dabbed, walls must be skimmed 1st ?
I was taught (when i was an apprentice) to tile directly onto the rear of a plasterboard,,, done a few and never had a problem ?

 

[Dumbo]

Tiling direct to plaster board is stronger than tiling to skim coat as plaster comes away from plaster board at about 20kg psqm where as paper comes away from gypsum core of plaster board at 28 kg psqm . If these figures are incorrect please free to correct me but that is the general idea. .

 

[Flintstone]

32kg for plasterboard but yes, anything is better than bonding. It's ok if there's a small patch up hole or something but not big areas, imo

 

[On one]

If you have a plasterer coming to undercoat your walls and you are tiling floor to ceiling, it only takes another 30 mins to go over the walls with finish plaster......the finish plaster doesn't even need to be smooth or finished off.