Plumbing

Pros and cons of non return valve

Anonymous user 01/09/2025 - 12.01 PM

I have installed an ensuite on the first floor of my house, on the other side of the house to where the pipes connect to the drainage. We have a set up such that there is a long length of pipe across the house (hidden in boxing) that takes the soil pipe and the water pipe from one end of the house to the other. In an ideal world we should have installed a new drainage set up on the ensuite side of the house but we had run out of money by then. A few months after the end of the renovation we are already having problems with the ensuite drainage. The pipe isn't seriously blocked (we've had the whole length examined) but there is some sort of build up. When you empty the bath, sometimes water comes back up through the shower before (ie. flows in the wrong direction) before eventually going through the pipes across the house and out. We have been advised to install a non return valve so that when water drains out the bath, it can't back up through the shower and flood the whole bathroom. My question is this: does this solution make sense given that the pipes traverse the house? I would rather have the water back up into the bathroom than have a blockage/leak occur elsewhere - potentially in a pipe in the boxing that traverses the house. My gut is that it would be better NOT to install the non return valve and instead focus on regular maintenance of the pipes (using unblocking liquids regularly for example). Any advice would be appreciated - thanks!