by Gareth Thomas »
Sat Feb 16, 2008 6:53 pm
You need to fit in a Non Return Valve in the plastic drain pipe run, between ur trap and soil pipe. You shdnt have a smell with a trap anyway, unless your foul water is backing up. Either way a non return valve will do the trick. They are sometimes known as condom valves as they have a rubber tube in them. The tube will allow water to flow out through it, but not back.