hello, i'm going to be changing the waste pipes in my bathroom, the basin is running at 32 mm and the bath is running at 40 mm. thats not he problem, they both enter the soil sack, bath waste is lower, then the basin waste comes in about 350 mm higher up. Can i use 40 mm for the bath and as it runs past the basin, drop the basin waste into the same pipe using 1 pipe for both flows? please help. :?
Sorry to disagree with everyone else, but although sometimes you have to combine wastes, it is not good practice to do so. Two problems occur. Firstly, when the plug is pulled in a full basin, water will often flow up the bath waste and cause a gurgle in the trap. sometimes water can actually flow up into the bath. Secondly, when the basin empties, and the water drains away, it can pull all the water out of the bath trap breaking the seal and allowing odours up into the room.