P
Perfect Tiling
Apart from using ply that was too thin (don't rely on the plumber...your'e the tiler!!!) why did you use BAL primer when using Topps own adhesive. You should never mix different companies products. If you are using BAL primer then use BAL adhesive and do everything by the book. If you normally use 12.5mm hardi then I would stick with it...It may be more expensive but its cheaper than having to redo the whole job off your own back...sorry but it looks like you will need to lift the lot and start again.