Hire the best Bathroom Renovator

Waterproofing over tiles?...

Results 1 to 6 of 6
  1. #1
    Senior Member Batpig's Avatar
    Join Date
    Sep 2007
    Northern Brisbania...

    Default Waterproofing over tiles?...

    Dear Sirs,

    This topic may sound familiar, but I couldnít find any threads specifically relating to it. My Bathroom is on a suspended concrete floor, and the ceiling below has been formed by "wet-plastering" the underside of the said concrete slab. The part of the ceiling directly below the Floor Waste pipe in the Bathroom is showing signs of water damage, with general discolouration and slight lumpiness over a small area of just a couple of square feet.

    The problem is most likely being caused by a small crack in the slab that has probably been induced by the casting-in of the Floor Waste inside the slab during the original concrete pour. I canít see a crack from above - because of the Bathroom floor tiles - but Iíve picked away at a small section of the damaged plaster ceiling below, and Iím pretty sure that I can see a bit of a crack in the exposed underside of the concrete slab in at least one area.

    If possible, I donít want to lift the Bathroom tiles to waterproof directly onto the slab or tile bedding in the more conventional way. I am therefore wondering whether there is a truly effective product for waterproofing the surface of the existing tiling - grout and all - that will wear well, and wonít make the tiles unduly slippery underfoot. I donít know a heck of a lot about "Tile Sealers", but something better than the usual run-of-the-mill might be warranted in this situation.

    I am also wondering about the best preparation to get the tiles "squeeky" clean before applying the sought-for waterproofing product.

    Recommendations of any decent Brisbane-based Waterproofing contractors who you think might offer a good solution would also be welcome, because I want to get the shower-recess professionally waterproofed before any new tiling goes on in there anyway.

    Many Thanks,

  2. #2
    1K Club Member journeyman Mick's Avatar
    Join Date
    May 2003
    Kuranda, paradise, North Qld


    Quote Originally Posted by Batpig View Post
    .............I am therefore wondering whether there is a truly effective product for waterproofing the surface of the existing tiling..............

    There isn't. There a re a few products that can be applied over the tiles and grout but they will leak over time - how much time is anyone's guess.

    "If you need a machine today and don't buy it,

    tomorrow you will have paid for it and not have it."

    - Henry Ford 1938

  3. #3
    PLU.MBR.BL.DR. bricks's Avatar
    Join Date
    Jan 2007
    Adelaide - West


    Product is called shower seal and comes with ten year warranty if applied by a plumber or builder with a liscence, available at Reece or similar plumbing stores cost about $100 for the product.
    If you dont play it, it's not an instrument!

  4. #4
    Senior Member
    Join Date
    May 2007
    Darwin NT


    If you can see a distinct crack underneath you could try epoxy injection. Probably not applicable for your job, but I have never seen anything you can add to the surface of a bathroom floor that will do a permanent job.

    We used to use Epirez hydrophillic epoxy, (water compatible).
    The technique is easy and cheapish compared to any other way of doing it.
    Grind a vee in the crack, bed in standard grease nipples at say 200 centers with epoxy mortar, filling the crack as you go. A couple of days later you pump a thin epoxy into the nipples with a grease gun.

    Start with just one nipple tight and the other loose, and as the epoxy reaches the next one, tighten it and pump from that one and so on.

    A day later grind off grease nipples.


  5. #5
    A Member of the Holy Trinity silentC's Avatar
    Join Date
    Aug 2003


    How old is the house? Are you sure you don't have a case of concrete spalling there? If you have a crack in the floor and there is moisture coming through, I think I'd be pulling up the tiles to check what's going on underneath. Spalling happens when moisture gets to the reo causing it to rust and it expands cracking the concrete.
    "I don't practice what I preach because I'm not the kind of person I'm preaching to."

  6. #6
    Senior Member Batpig's Avatar
    Join Date
    Sep 2007
    Northern Brisbania...


    No, definitely not spalling SilentC. The concrete is quite sound above the plaster where the lumpiness is at it's worst.

    Billbee - epoxy injection from below sounds interesting, but could be overkill. Will have a closer look at the pattern of the cracking to see if it is suitable for your proposed method when I get a chance to get all of the affected plaster off the underside of the slab.

    Bricks - Shower Seal sounds good. Could perhaps apply it to the tiles above, leave the plaster below alone for a while to let things dry out a bit, and then re-plaster down the track. Plumber will be coming out soon to put a new combination in the wall of the shower recess, so I'll talk to him about the possibility of bad joins, etc, in the PVC before I do anything else. You wouldn't perhaps know who manufactures the Shower Seal would you? There are a couple of outfits called Shower Seal that come up when you do a Google, but they appear to be more along the lines of Waterproofing contractors...

    Thanks to all,

Similar Threads

  1. waterproofing brickwalls
    By john9996 in forum Structural Renovation
    Replies: 4
    Last Post: 3rd Jul 2011, 09:43 AM
  2. waterproofing for tiles
    By western6deputy in forum Tiling
    Replies: 2
    Last Post: 14th Dec 2007, 09:47 AM
  3. waterproofing
    By cabman in forum Bathrooms
    Replies: 0
    Last Post: 29th Jul 2007, 06:54 PM
  4. Waterproofing
    By Flyboy in forum Kitchens
    Replies: 1
    Last Post: 6th Jan 2006, 01:31 PM
  5. Replies: 2
    Last Post: 30th May 2004, 08:25 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts