newbie question - TilersForums.com

[pomm001]

The grouting on my en-suite looks poor and starting to drop out in odd places. On closer examinatin a couple of the tiles when 'tapped' have a hoolow ring, so carefully pulled a couple off.
Some damp has got behind onto the skimmed drywall, pulled off all tiles until the skin was dry. The adhesive on the tiles just came off withou much effort.
The shower walls have dried off and i want to put the tiles back on and re-grout, i have had advised to use an acrilic PVA bonding agent first , i have some weber PVA PR370 would this be any good ? also what type of adhesive i have some weber rapid plus and some soverign super grip kicking about, any good

many thanks

 

[Ajax123]

moisture, gypsum (finish skim) and cement (tile adhesive all together = ettringite formation = tiles falling off the walls. Acrylic primer generally won't prevent it unless numerous coats are used and only then if there is little or no moisture present.

To stop ettringite formation you need to elimiate at least one of these elements - preferably the damp cos it will also damage your walls.

PVA is no good as a primer and should not be used in tiling. A proper acrylic (not acetate) primer should be ok if you eliminate the damp.

If you can't eliminate the damp then ????

 

[pomm001]

Thanks for the info
Yes i have stopped the cause of the damp and the wall has dried
Interesting what you say about the PVA primer never being used, my local tile shop sold me this weber product a few weeks ago ( not for this job though)
So i need to get acrilic primer, any recomendations
thank you

 

[DHTiling]

Have a read of this..

http://www.tilersforums.com/tile-adhesive-grout-prep-forum/2511-p-v-versus-primers.html

 

[2020Tiling]

iam well happy after reading pva v primer ! i to didnt no that pva was the devils juice untill i joined hear :hurray: i think we should try and get it on news at 6 so everyone understands that pva has no purpose at all in any tiling situations . :mad2:

 

[doug boardley]

iam well happy after reading pva v primer ! i to didnt no that pva was the devils juice untill i joined hear :hurray: i think we should try and get it on news at 6 so everyone understands that pva has no purpose at all in any tiling situations . :mad2:

I agree Terry:20: