Normally I lay shower trays on a bed of weak mortar but Adamsez individually level their trays by grinding and shimming. If the floor you're laying on is level or very near it then all you need is some generous dobs of silicone under those support points. So much for a silicone free tray. Seriously though, these dobs are there for levelling not sealing. The wall sides of the tray incorporate upstands and as good as these are they do produce a kick on the tiles unless you can let them into the wall. Now we all know that corners are rarely square so you might be letting one side in more than the other to make sure the upstand doesn't protrude. Having satisfied myself that the tray was in far enough not to produce a kick I deviated from the Adamsez manual to introduce a belt and braces measure in the form of a Dunlop Leak Proof Shower Sealing Kit. This consists of a primer, close woven scrim tape and sealant. This was stuck to the walls and run up the internal corner where the masonry wall met the stud wall. This is common place for movement and once water tracks down behind tiles it will end up on the ceiling below. As the stud wall was 100 years old I didn't expect any shrinkage and provided I kept the water out I knew it wouldn't swell either.

Once the tray was in I set about tiling the floor using Dunlop's rapid Set floor and Wall Tile Adhesive. This is a flexible adhesive suitable for timber substrates and compatible with underfloor heating. As I chose the hottest day of the year to tile the floor I could have done without the rapid set. I hardly managed to lay more than three tiles before the adhesive went off. I made sure that the bucket and tools were spotless each time I mixed up a measure but it was still much too fast for me. Two days later the weather cooled a bit and I found that the open time increased by 20 minutes which was ideal.

As a general point it is always worth spending a little more time mixing tile adhesive because the powder must dissolve properly to allow you to comb through without dragging. If you have an even substrate and you comb through at right angles every time the tiles will be flat. These marble pattern tiles from RAK Ceramics are 15mm thick but they have a very square edge, so you have to make sure that the edges are completely flat so you can achieve a nice flush grout joint. Where a continuous bed of adhesive is required, a notched trowel with carbide tips such as this one from Benson can be used. This effectively stands the notches off the surface so the adhesive isn't then combed all the way back to the substrate.