STUB STACKS
Where a group of appliances or a WC on a ground floor is connected directly to an underground drain, a stub stack of 110mm diameter pipe can be used.

Ventilation is necessary if the distance from the highest appliance connection to the stack to the invert of the drain is in excess of *2m, or if the distance from the crown of the WC connection to the invert of the drain is in excess of 1.5m.

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