Bonding plaster and tiling so much confusion.....pls help

[callard]

HI, i am new to forums and alike so be gentle with me pls

Ok here goes......took tiles off in the bathroom, some plaster and bonding came away as well, it was blown and not secured to the breeze blocks so i used pda on the breeze blocks, got some bonding plaster and re-plastered where it came away(maybe i should have used browning?)

I was hoping to tile straight on to the bonding plaster like i was told i could but on looking around the web i have seen many conflicting stories...some say tile on it others say it will absorb water from the adhesive and the tiles will fall off, So i thought i would pda it then tile some say this is ok others say that it will only be bonding to the pda and if it got wet then it would revert back to a sticky solution and the tiles would fall off again....however on the adhesive it says pda the wall 1/5 parts....so as you can see i am really confused.

I have very little room to play with but would it be better if i were to do a very thin skim over the parts that i plastered? thing is i could only get away with about 1mm thick would this be enough.

Finally the bonding plaster is drying nicely all be it with cracks, is this normal or have i done something wrong again

All advice would be really appreciated.

Many thanks
Callard.

 

[gcol]

You don't tile onto bonding or browning. You need to skim over it as you have suggested.
What adhesive are you using?

 

[callard]

Hi I have bought unibond tile on walls shower and bathroom adhesive.

Because i am impatient as i want to get on with the job i rang quite a few tile stockists today and it was 50/50 half said just tile on the bonding and half said to skim, which has made me more confused, also half said to use this unibond stuff i have bought and half said to use a Bal product, surely if the Unibond stuff was no good then they would have so many complaints places like B&Q and Homebase would not stock it as it would be too much hastle?

I rang Unibond techy department today and they were quite happy for their product to be put on bonding plaster as long as it was pva'd 5-1....and their lies the question to pva or not to pva.

I have been looking at a few things on the net and this pva thing is a real minefield...... some guys won't even mention it's name and others have used it for 20 years in their work without a problem...... for the average diy-er like myself who gets pleasure doing things like this it gets very confusing because you see so much for and equally so much against and quite honestly don't know which way to turn half the time......with this pva thing i just find it amazing that a big company like unibond would tell you to pva a wall before tiling when it seems to fly in the face of what the professionals would do....all i want to do is the right thing and hopefully the tiles will keep on the wall for many a year.

 

[gcol]

I try to steer away from Unibond products.
Here's what I'd do if I was in your shoes - this will work no problem.
1. Take the unibond stuff back.
2. Skim over the bonding or browning plaster. The skim will only be very thin as you said, so it will dry quickly.
3. Get yourself some Bal White Star and stick the tiles up with that. http://www.bal-adhesives.co.uk/bal/bal_products/white_star.asp Topps Tiles sell Bal adhesive. However if your tiles are large (300mm x 300mm and above) you ideally want to be using a powdered adhesive that you mix up yourself. No pva with either product for bathroom use.
4. Use a decent powdered grout like Bal Microcolour http://www.bal-adhesives.co.uk/bal/bal_products/microcolour_wall.asp

 

[flyingcat]

hi, gcol, may I ask a question: why don't tile on bonding plaster directly? what's the skim for?

and does "skim" mean using "finishing plaster" on top of bonding plaster?

look forward to your reply. thanks a lot!

 

[gcol]

hi, gcol, may I ask a question: why don't tile on bonding plaster directly? what's the skim for?

A couple of reasons really: bonding plaster is very porous and will wick moisture away from the adhesive very quickly which can cause curing problems. The other problem is that it is not strong enough to allow the adhesive to get a proper grip.

and does "skim" mean using "finishing plaster" on top of bonding plaster?

Yep.

 

[joe-90]

I rang Unibond techy department today and they were quite happy for their product to be put on bonding plaster as long as it was pva'd 5-1....and their lies the question to pva or not to pva.

As you might imagine, the tech department is spot-on.

You get more nonsense talked about PVA on a forum than any other subject.

Manufacturers test their products extensively - so why listen to someone on a forum that doesn't even use the stuff?

And as you so rightly point out - the shops like B&Q and Homebase would have dropped the stuff 30 years ago if it didn't do what it said on the can.

Common sense really.

 

[flyingcat]

thanks so much for the prompt reply. very lucky haven't started to tile on the bonding plaster yet. will get finishing plaster tomorrow to continue my bathroom project.

gcol, i have more questions (sorry i have so many questions):

1. after applying bonding plaster, how long i should wait to skim the wall? someone said the bonding plaster need 6-8 weeks to dry. it's a very upsetting news as I want to finish my project before Christmas.

2. after skimming, how long i should wait to apply the tanking?

3. then how long I should wait to start tiling?

 

[joe-90]

Flying cat. If you want legal or medical advice then you go to a lawyer or doctor - not an Internet forum.

Similarly, if you want technical advice on a product then you go to the company's technical department - which is what you have done.

What is the problem here?

 

[gcol]

thanks so much for the prompt reply. very lucky haven't started to tile on the bonding plaster yet. will get finishing plaster tomorrow to continue my bathroom project.

gcol, i have more questions (sorry i have so many questions):

1. after applying bonding plaster, how long i should wait to skim the wall? someone said the bonding plaster need 6-8 weeks to dry. it's a very upsetting news as I want to finish my project before Christmas.

You can skim the wall when the base coat has hardened.

2. after skimming, how long i should wait to apply the tanking?

Have a look at the data sheet on the bottom right of this page http://www.bal-adhesives.co.uk/bal/bal_products/wp1_tnk.asp
Here it'll tell you that you should wait at least 4 weeks before applying the tanking product to allow it to dry out. If it's just a skim coat, it'll dry quicker. There's nothing to stop you getting a dehumidifier in to speed up the process though.

3. then how long I should wait to start tiling?

24 hrs

 

[gcol]

Flying cat. If you want legal or medical advice then you go to a lawyer or doctor - not an Internet forum.

Similarly, if you want technical advice on a product then you go to the company's technical department - which is what you have done.

What is the problem here?

I can't believe you've just written that Joe. I'm gonna post this on the general discussion board so no one misses it.

Edit: I'll save you the embarressment. My advice to you is to stop talking balls.

 

[joe-90]

I never override the instructions of a manufacturer as the manufacturer is legally bound to represent their product accurately.

I suggest you adopt the same attitude.

 

[jefoss]

Flying cat. If you want legal or medical advice then you go to a lawyer or doctor - not an Internet forum.

Similarly, if you want technical advice on a product then you go to the company's technical department - which is what you have done.

What is the problem here?

I can't believe you've just written that Joe. I'm gonna post this on the general discussion board so no one misses it.

Edit: I'll save you the embarressment. My advice to you is to stop talking balls.

now now guys no need to get bitchy to each other is there? i think if this continues there should be pistols at dawn, if you need ill let you know where dawn lives

 

[gcol]

Don't worry about it jefoss, Joe likes to bring up the same argument every few months. The thread will probably end up being locked and he'll toddle off back to the general discussion forum where he will constantly patter on about immigration and such.

 

[joe-90]

You have never answered the question gcol - manufaturer's give the right advice for their product - why can't you see that?