Branch Connection Spacing
Building Regulations and BS EN 12056:2000 place dimensional restrictions on the vertical spacing of branch pipe connections to single stack soil and ventilating systems, and on the lowest connection height.
These restrictions can be summarised as follows:
1. Branches of any diameter should not be positioned opposite each other such that effluent could discharge across between them, or potentially cause blockages. Waste branches may be connected in opposing directions if there is an adequate vertical spacing.
Opposed branches serving WC’s can be connected to a stack at the same level using a double branch fitting, in which the branch pipes are angled or swept into the main stack.
2. No other connection should be made less than 200mm lower than an opposing WC branch connection: a 50mm parallel branch connection can prevent this situation, or the connection can be at the same level if perpendicular to the WC connection.