I have 10mm thick 45 x 45 cm square tiles to be laid onto a concrete substrate. What depth of adhesive should I use and what grout thickness will be acceptable, I was hoping to go for 2mm, is that too narrow?
Used 6mm adhesive applicator and 1mm spacer in the end
We use 9mm depth of adhesive for floors which squishes down to around 4mm - the comb type applicators are preset to this. For grout joints we use removable/reusable spacers which are around 4-5mm - anything less may look a little out of proportion but that's up to you.
You might want to seal the concrete with a diluted PVA primer before you tile on it. If the concrete surface is bumpy and uneven, would recommend a coat of ragreage first before you tile - makes tiling so much easier.