T
Tile Shop
Thanks Paul.
Very helpful. The wall is pretty level (30-60 cm height x 2-3 m long).
We are using porcelain tile (10mm) what brand of s1/2 adhesive would you recommend?
Unfortunately we have not put in a damp proof on the back of the brick which has been filled with soil! The brick's water absorption level is less than 7%. Would this still be problematic for sulphates?
The 3 most popular choices of adhesives among tilers on here are Mapei, Weber and Tilemaster. With porcelain, you will be fine using a slow setting adhesive so something like Keraflex S1, Weberset SPF or TM Standard Setaflex (rapid setting versions of each are available)
Now, about your sulphates...... yes they could be a problem. Unless you are prepared to dig the soil out, wash and dry out the wall and put some form of tanking, there are no guarantees. Without it, you'll be lucky if you get 2 successful years out of your adhesive. Maybe 3 if you add some extra polymer to the mix.
There are some DPM's but neither Ardex or Mapei are able to offer a confident answer to whether they work for a wall situation, so at your own risk if you want to attempt it.
Now, although its not designed for this, but I can see no reason why this would not work, my "idea" is to use Marmox 6mm Multiboard (suitable for external use), screwed to the wall at 150 to 200mm intervals using their fixings and washers, tape the joints with the Marmox waterproof tape, tape over the washers too and that has a 90% chance of surviving beyond the 2 years as it will repel moisture from both directions.
At that short height all this probably sounds overkill, but its the only way I can see it having half a chance.