Please can I have some advice regarding external tiling. This is a school project, I am a ceramicist. Job: There is a brick built circle in the school garden. The children made thick ceramic ( stoneware) tiles to decorate the top of the brick circle. Each tile is approx 20 x 20 and 1cm thick. I want to tile directly on to the brick. It needs to be weather proof ( frost proof) and it needs to be permanent. The tiles are not glazed on the underside and have been grooved to help with bonding. What is the best (pre mixed) adhesive/grout should I use? I am a competent tiler, both wall and floor but only internally. This project is outside. Any advice would be greatly appreciated Thank you
Limited in choice with exterior ready mix. With bagged, something like ARDEX X 7 G PLUS or Ardex Microtec X77 which is available bagged or premixed. https://ardex.co.uk/product/ardex-x-77/
As the others suggest - use bagged adhesive. Better quality, ideal for the location and cheaper! You can mix what you need and keep the remainder for the next batch.
For the OP ... https://ardex.co.uk/products/grouts-silicones/ just remember to chose one that is suitable for te gaps you will have. The FL for example is suitable for external use (although I suggest you call Ardex to verify your use) and will work from 3mm to 15mm, available in 35 colours so you could chose one which matches the school uniform colour!
You need something cement based to withstand the weather. You'll need to prime the surface with SBR before tiling.
Easier in that you do not need to mix, however results will often be no where near as good and the range of adhesives limited. With the Ardex (and other) bagged, you weigh out what you need, add the requisite water, mix up and off you go. Less waste too.
I rarely used tubbed Addy now. Ok for kitchen splashbacks etc, but Often have a few remnants of bagged adhesive left over and used some up on the last splash back a couple of weeks back. The only disadvantage is the need to prime. I pay £10 for a 20kg bag of Addy and £15 for SBR. A tub of of bal greenstar or similar is about £8, so more outlay, but in a bathroom, I only use bagged now.