Any advice would be welcome. I've just finished re-grouting and resealing my shower, and now I'd like to have a go at the outdoor tiles, as the water is getting under them and we're getting efflorescence at the edge of the slab (where it meets the garden).
Our plumber has advised that the they're tiles and not pavers, and that they're not sealed and so are probably absorbing water. I don't want to use an epoxy given it's harder to work with and can discolour the tiles and has a shiny look, and also have been advised (by plumber) we need a sealant that soaks into the tiles, rather than being painted over the top.
Will a simple Davco or Dunlop cement grout do?
There are a ton of water-proofing sealers - it's hard to tell which is best - any advice would be welcome.
Welcome to the Bunnings Workshop community @DIY_Dinkum. It's wonderful to have you join us, and many thanks for your question about sealing tiles.
Water is accessing the adhesive behind the tiles, causing this issue. The problem with sealing the surface of the tiles is whether that's the only access route the water has. I'm not sure what those tiles are adhered to, but if the water is coming up from underneath, sealing the top isn't going to help.
If there is no glaze or sealant on the tiles, you can use Crommelin Natural Diamond stone sealer. It's a penetrative sealer that will soak into the surface of a porous tile. To test if there is a coating already, apply a few drops of water to the tile's surface. If in 20mins the water has soaked into the surface of the tile, then you can use this sealer.
The sealer will obviously trap those existing efflorescence marks, so it would be best to try and remove them before sealing.
Please let me know if you have any questions.
Thanks Mitchell, much appreciated - that product looks perfect.
Will a cement grout be okay for outside, and will the Crommelin seal that also, or do I need a separate sealer for that?
As long as the cement grout is labelled for exterior use, it will work just fine. There's no need for a separate sealer for the grout, the Crommelin Natural Diamond stone sealer will work on it as well. Please make sure to provide enough time for the grout to cure. Any trapped moisture in the grout will make the seal ineffective.
If you need further assistance, please let us know.
As Mitchell has already said….you really need to fully understand exactly where the water is coming from - rising ground water, water under the tile from elsewhere or directly soaking though your tile and/or grout from above?
A sealer will only help with the last scenario as it won’t help with negative hydrostatic pressure (water or water vapour pushing up from below).
Additionally, sealers are temporary and have limited impact dependent on numerous other factors. Good design, preparation and installation of a tiled or paved area are far more effective than a sealer.
I’d suggest that the way your tiles/pavers have been cut that at the very least the installation part has been rushed and is not the work of a quality tradesman.
To fix your issue would require mechanical removal of the efflorescence (not easy), ensure you have no water coming from below or surrounds, grinding grout and replacing and then then sealing (if your tiles will allow). A lot of work.
You may consider taking it up and starting again with sufficient drainage and good sub-paver/tile preparation…..if of course time and money permit.
Yeah, cheers, there are other factors that I didn't list in my question as it's quite complicated - for now I'm just trying to discount that water is getting in from above (I suspect there's water coming in from behind the cladding from the balcony two storeys above), so that I can push the body corporate to address the issue. We're eventually going to replace all the tiles and get a more permanent water-proofing solution, but for now I need a low-cost stop-gap measure that I can do myself.
Thanks for the feedback; all good points!
Keep us updated @DIY_Dinkum, and please reach out if you need further assistance. We're here to help.