I have been asked to help out with a soil stack which is not vented. It seems the local council are not impressed. The soil stack slopes gradually down the outside of the house from the wc for about 4 meters, bends around the front of the house about 3 meters from the ground, then straight down.
I intended to branch into the soil stack as it reaches the front of the house and vent straight upwards. However, because of a front porch and a very narrow side alley, access is impossible without a helicopter.
Can someone tell me if it is allowable to branch the vent pipe into the sloping pipe on the side of the house, or does the vent have to be vertically above the soil pipe entry into the manhole?