Tiling On Concrete

Discussion in 'Tilers' Talk' started by nev, Aug 20, 2004.

  1. There are actually two types of PVA,

    Poly Vinyl Acetate
    Poly Vinyl Alcohol

    One is water soluble, one isn't

    They are both commonly referred to as PVA and I've yet to find a container that labels in enough detail to tell you which one you have.

    I'm not a chemist and don't claim to be, but I've had long conversations with both BAL and Ardex technical depts who gave me exactly the same information about PVA. I've no reason to disbelieve them especially as they explained in very reasonable details what happens if you do use it incorrectly.

    Early in my tiling career I had a major failure as a result of PVA (which had been applied without my knowledge) The job cost a great deal of money to correct, it was at that point I understood what to use and what not to use.
  2. dj.

    dj. New Member

    gasgit, you have kind of answered your own question. you used waterproof pva and that put a total barrier on the wall you need the pva to "come back" then the plaster takes to the pva. if you use normal and not waterproof, you spread plaster onto the wall, the water in the plaster makes the PVA live but stops the plaster from penetrating the substrate and providing a mechanical grip, thus giving a barrier from the existing wall plus an adhesive for your new skim. waterproof pva is a big no no under plaster, you will never get a mechanical grip by plastering over waterproof pva.

  3. branty1uk

    branty1uk New Member

  4. Yes I have, I used to use all Ardex products until my local supplier switched to BAL.

    I was always the standard for me but it's just a pain to get hold of it now.

    Also when you compare it to some of the standard BAL products which comtain Porcelbond and you don't need the admix it can get a bit pricey.

    Even now I still compare everything to X7. That's the standard.
  5. owen

    owen New Member

    Went to my local tile supplier last week to get some adhesive for some kitchen tiles i was fitting, he gave me nicobond ready mixed. I asked him what to prime with and he said...............PVA!

    I queried this, and he reckons that the specialist primers are only overpriced PVA anyway, so he doesn't keep them in stock. I didn't have time to fanny about trying to get the proper stuff as he's the only proper tile supplier for about 10 miles and i was in a rush, so i used PVA and crossed my fingers. Time will tell if i regret this.

    Now I am convinced by mudster's reasoning against PVA, but i am concerned that a supposedly "proper" tile supplier can recommend this? What do you reckon mudster?
  6. branty1uk

    branty1uk New Member

    Mudster, that particular adex dosent need an admix for porcelain, although it is dearer than bal adhesive. In my opinion it is better though.
  7. branty1uk

    branty1uk New Member

    Thats the question Owen, is it a proper tile supplier if its recommending PVA?
  8. Branty, To be frank I'd be happier using Ardex than BAL, I find the BAL a little overpriced for what a lot of it does.

    Some of the local suppliers I use stock the basics, X7 & S16, but not the products that are really useful, S21, S38 (which I think is what 5001 was a replacement for, or was 6001?).

    Plus, fitting slab stone I'm using such large quantities I'm buyin a pallet at a time and I've found one or two of the Nicobond products great value for money.

    Have you tried the Ardex S20W yet? The adhesive designed specifically for Stone fitting, I've yet to find a supplier willing to sell this to me, it seems to be special order only.
  9. Owen,

    Like Branty says, this is just plain unsound advice, your tile supplier has made an assumption about what the primers are made of without any research or technical information.

    It's not sound, and I get quite irate at so called professionals giving this sort of misinformation.
  10. Washboy

    Washboy New Member

    Ardex are coming out with a new version of X7 with an inbuilt porcelain additve - so there'll be no need to buy the admix when fixing porcelain. i don't think there's much differnce in the price. Should be on the shelves now, or very soon..

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