I am looking at a 1600 long former with linear drain. Would the 20mm depth produce enough fall for that length? Also is the fall degree the same in all depth of trays?
Yes. Even 20 mm thick tray provides sufficient slope for free water flow. We have tested that even with 0.5% of slope water will still be drained, while the tray has approximately 20 mm. However thicker tray provides more slope so if you're planning to have plenty of water going through your shower area it may be a good idea to choose a thicker one.
I am happy to assist if you have any questions.
David 020 7193 0953