What are the rules around soil vent pipes? I ask because at work, (a newly refurbished building with a new wooden floor and no access underneath where the drains run) they fitted a toilet with its waste pipe going straight into a 90 deg bend and into the floor, and a rodding point on top of the 90 deg bend (which is useless, the guys who rod it just pull the 90 deg bend off completely - it blocks frequently).
Anyway, there is no facility to vent here, so adjacent to the toilet waste is a ~50mm pipe emerging from the floor, which the kitchen sinks and wash hand basins drain into, and the pipe carries on up into the roofspace, where a non return valve is fitted as a vent. As I said, this pipe is only about 50mm (dont know exact sizes sorry).
I thought vent pipes had to be 100mm, so they could take in plenty of air when the bog is flushed.
And why put the non return valve in the roofspace, why not a shorter upstand for it? (I have seen this, where the toilet was upstairs, and the vent was just above the toilet cistern)
Anyway, there is no facility to vent here, so adjacent to the toilet waste is a ~50mm pipe emerging from the floor, which the kitchen sinks and wash hand basins drain into, and the pipe carries on up into the roofspace, where a non return valve is fitted as a vent. As I said, this pipe is only about 50mm (dont know exact sizes sorry).
I thought vent pipes had to be 100mm, so they could take in plenty of air when the bog is flushed.
And why put the non return valve in the roofspace, why not a shorter upstand for it? (I have seen this, where the toilet was upstairs, and the vent was just above the toilet cistern)