The sub stack was installed in the house when built with a non vented cap, so I'm assuming that it must be within 2m from the ventilated drain. It is also less than 2m from the toilet, sink, and bath.
Think I understand what you are talking about.
Bstr
Correct about the end cap this is a screw cap and is not vented, does this mean the other stack would handle any flood level, and this "stub stack" is only to provide a fail safe in the event that the other stack is blocked ?
There are 2 rodding drains 1 at each of the stacks outside...
Thanks for the reply.
If it is the highest trap then this would allow me to reduce the size to 1m, as the highest trap is the bathroom sink in that room.
I wasn't sure whether it would be the height of the sink as when full this would have the greater head of pressure (just guessing here...
Thanks for the prompt reply, I thought it might have somthing to do with that.
As a matter of interest why does it not join to the other stack which vents to the outside ?
Thanks
I have 2 types of soil stacks in my bungalow :
The first is in my internal ensuite which runs into the attic and then vents externally through the roof.
The second is in my main bathroom and only runs to a height of 1.5m, where there is a white cap which can be unscrewed (I'm assuming this...