Hi all, just looking for some advice, apologies for the long windedness but I prefer to give all the info We are just about to complete the tiling of our bathroom walls with 600x300 glazed porcelain tiles. We did the research and did all the prep, tanking and priming the walls (which are concrete render - its a 50's house!), went out and bought Mapei powdered adhesive because we read readymix stuff isnt suitable for porcelain tiles. We back buttered the tiles and have left battens up to keep them in place so they could set properly. Everything we thought we had done right. The tiles went on a dream and feel pretty firm and well set. The 'oldest' tiles have been up for just over 2 weeks now (its taking a while as we both work full time). However we went to pick up a couple more bags of adhesive last night to finish off and only then realised that we have bought and used the mapei ready mix fast setting adhesive for ceramic tiles, when we apparently should have bought the stuff for porcelain tiles. I've looked for hours last night trying to find what the difference is between the two adhesives and all I can really find is mixed opinions that the tiles may or may not fall off at some point in the future because we used the "wrong" adhesive which is designed for ceramic tiles. Is there really a difference? If so how can Mapei also get away with selling a different bag of adhesive designed for both porcelain and ceramic if they are different compounds/ingredients? We are obviously worried that one day (and who knows when) the tiles are going to suddenly drop off, which could be lethal, but at the same time thats hours/days/weeks more time needed to get the tiles back off the wall, scrape the walls again, re-prep and re-tile Is it a genuine issue? Thanks in advance!