I had a very interesting discussion this morning with a technical guy from a major company, I had a question about a product which he answered, but in the process he sent me a link to a video to show what needed to be done and in that video it showed something that caught my interest, and from following conversations with him made me realise that it was something that I personally was unaware of and had never given it much thought, but it showed me that current British Standards are again slow at changing to match new products.

It has become important that we reduce our use of water, manufacturers have risen to this with taps that restrict the flow rate and WC’s with smaller flush volumes, we have reduced our flush volumes from, 12 to 9 litres, then down to less volumes with modern cisterns of 6 litres, but we are moving towards even lower flush volumes of 4.5 litres, I have fitted these 4.5 Litre flush pans, now these pans are designed to remove the solids from the pan with the 4.5 Litre flush, the problem comes with the drainage, currently regulations call for 110mm drainage for a WC pan, but with this bore of pipe and the lower volume of water used to flush the WC (4.5 Litres) the 110mm bore means there is insufficient water level within the bore to take the solids away over longer distances, even if the correct gradients are used, with these lower flush WC’s we need to be using 90mm drainage pipes, these allow the bore to fill more with water on flushing the 4.5 Litre WC’s and so carry away the solids, here is a great video from Geberit that shows the problem https://www.youtube.com/watch?v=8iEx-xB2POs are the regulations going to be changed to take into account the use of 4.5 Litre flush WC’s which will only increase over time, I was not aware of this issue and I can see future problems as more and more low flush WC’s are fitted to existing drainage.

Now I like to think I keep up with regulations and changes within our industry, but I was totally unaware of the potential problem, am I alone on this, was anyone else aware, are the regulations been reviewed to update on this