First job with this type of stone (have laid floor and wall tiles several times successfully) Sandstone paving (B&Q bought says from India) 300x600 by 20mm thick. Laying on a solid concrete base - little uneven in places, but pretty decent. Small area - about 20 stones half of which will need 1/4 cut off (using angle grinder with appropriate disc)
Using an appropriate adhesive from Bal or Mapei (Mapei Keraquick Wall & Floor Rapid-Set Flexible Tile Adhesive White 20kg - https://www.screwfix.com/p/mapei-keraquick-wall-floor-rapid-set-flexible-tile-adhesive-white-20kg/7685v). So...questions.
Planning on using a 12mm trowel (achieve bed thickness of around 6mm). Adhesives I looked at are good to around 10mm thick. Is the trowel and bed thickness suggested appropriate? I considered a 20x10mm trowel.
Do I need to back butter the stones. I'm using rapid set adhesive and this will obviously slow me down if needed, however I will do if required. The back of the stones have little ridges along them (assume from engineering to get a uniform thickness). Not so easy to back butter because of it. If needed I will likely mix the adhesive in smaller quantities to allow time to butter. Will have them all cut and laid out ready to go before mixing.
So in summary - is the adhesive OK (their data sheets suggest they are) and is the trowel suggested ok? Back buttering or not?
I am very grateful for your time taken to answer my questions and put me at ease that I am on the right track or not as the case may be
Using an appropriate adhesive from Bal or Mapei (Mapei Keraquick Wall & Floor Rapid-Set Flexible Tile Adhesive White 20kg - https://www.screwfix.com/p/mapei-keraquick-wall-floor-rapid-set-flexible-tile-adhesive-white-20kg/7685v). So...questions.
Planning on using a 12mm trowel (achieve bed thickness of around 6mm). Adhesives I looked at are good to around 10mm thick. Is the trowel and bed thickness suggested appropriate? I considered a 20x10mm trowel.
Do I need to back butter the stones. I'm using rapid set adhesive and this will obviously slow me down if needed, however I will do if required. The back of the stones have little ridges along them (assume from engineering to get a uniform thickness). Not so easy to back butter because of it. If needed I will likely mix the adhesive in smaller quantities to allow time to butter. Will have them all cut and laid out ready to go before mixing.
So in summary - is the adhesive OK (their data sheets suggest they are) and is the trowel suggested ok? Back buttering or not?
I am very grateful for your time taken to answer my questions and put me at ease that I am on the right track or not as the case may be
