I have one of your 900 x 1600 20mm thick wiper trays. I am well pleased with it. I am about to start on my second ensuite bathroom and I do not quite understand why if you have a thicker tray the slope will be greater?
I am glad to hear that you are happy with our wet room tray installation.
This is correct. Thicker tray provides steeper slope. This can be beneficial if plenty of water is going through your shower area. However it will require more space to be installed.
Even 20 mm thick tray provides sufficient slope for a single shower head though.
I am happy to assist if you have any further questions.
David M 020 7193 0953