Tiling on a skimmed bathroom wall - HELP!

[sg0102]

Hi there,

I am in the middle of refitting my bathroom, and it is the first job i have done - i am trying to do the tiling myself.

Now, the old tiles came down, and the wall needed reskimming, which we have just had done.

My questions is can we now tile on top of this wall, with just waterproof adhesive on the tiles? Or do we need to put some sealant down first? We have started, without any sealant, but my Dad has just told me i need to seal it?

Can someone please advise (asap!?) - and what is the risk of not sealing?

Many Thanks

 

[DHTiling]

What is the adhesive you are using.?

how long was it since the wall was skimmed..?

And what size tile are you using..?

 

[sg0102]

Hi,
I'm using Unibond adhesive, waterptoof stuff. The skimming was done days ago.

Thanks
Steve

 

[DHTiling]

what size tiles are they...?.

when you say day's..how many please...?

 

[sg0102]

Sorry, the skimming was done on Thursday - some bits are a bit patchy still, but most looks dry. (Plasterer said it would be dry to tile in a couple of days).

The tiles are 41cmx30cm big.
THanks for your help

 

[DHTiling]

Hey no probs..........

Firstly.....that skim isn't dry enough...don't you just love it when another trade sez it will be OK....what is the skim onto..substrate wise....is it plasterboard or basecoat.?

The tiles are too big to be using a tubbed dispersion adhesive IMO, you will need to be using a cement based adhesive...are the tiles ceramic..?

 

[sg0102]

Thanks!

Yeah, i do love it!
The skim was onto plasterboard. How long should we be leaving it do you think?

The tiles are ceramic yes...

 

[DHTiling]

Thanks for be patient.....It will be fine to tile next week.....The skim not only needs to loose it's moisture but it also needs time to gain strength....2 weeks from the finish date of skimming will be ideal on plasterboard.......

good luck...

 

[sg0102]

Thats great, thanks Dave.

Another question, do i need to put any sealant down first? or can i tile on to the skimmed wall?

 

[DHTiling]

Sorry about that.......yes you need to use an acrylic tilers primer to seal the gypsum from reacting with the cement based adhesive you need to use.....if you do use a tubbed adhesive then no need to prime BUT it will take a whole lot longer for the adhesive to dry out.....

Tubbed dispersion adhesives need to loose their moisture with air contact...where as the cement based adhesive will dry hydrolicaly within a set time period, depending on whether the adhesive is rapid setting or standard setting....

The tubbed one could take days to properly dry....

hope this has helped you.....

 

[medlar]

i am with Dave on this mate,you should be using a powdered adhesive not a tubbed one

 

[doug boardley]

and don't let anyone talk you into using pva as a primer!!, 'cos it isn't!! might as well smear tomato ketchup on your plaster!

 

[brian c]

and don't let anyone talk you into using pva as a primer!!, 'cos it isn't!! might as well smear tomato ketchup on your plaster!

why is it when you ask older tilers why are you using pva and not acrylic primer?they say ive been using it for years and never had a failure and anyway that acrylic stuff is too expensive?

I know the pitfalls in using pva but they are just not interested when you try to discuss this....(no failures that they know about is what i say)

 

[doug boardley]

hopefully these guys will soon be retiring Brian, they never had access to internet or 'owt like it,I think we've probably gotta concentrate on the guys who are coming into the trade, rather than the older guys who, in all probability won't change.

 

[White Room]

I've allways used PVA for plastering and has allways worked for me and many others, Tiling is another ball game

 

[Gazebo]

I am with Doug on this one, lots of tilers i talk to still insist on using pva, when i mention acrylic primer and any tips i have got from you guys on here, they think i am being over cautious etc, 1 tiler even said i must have been talking to the tiling Police when i tried to discuss most stuff i have read on here, so yes concentrate on the new guys coming through is a good idea, in future i am going to keep my mouth shut when i am on a job as the plumber and the builder uses his own tiler, on my own jobs as a plumber and the tiler i will incorporate all that i have learnt here. and yes i am a plumber by trade, but a very nice plumber who gives consideration to tilers when i am on the job.
Merry Christmas to u all and thanks to all at the forum.
Gary

May the New Year bring prosperity to you all.