Investigation of single-stack drainage for multi-storey flats.

Abstract

DURING the past few years there has been much concern over the high cost of sanitary -L~ services for buildings. Among the reasons given for the expense are out-of-date byelaws, lack of research, reluctance of many local authorities to take advantage of developments in sanitary engineering, and ill-considered design. Criticism has often been levelled at the fully-ventilated two-pipe system of drainage for multi-storey building shown in Fig. 1, with its requirement of four main stacks-one for soil, one for waste and two for ventilation-and an individual vent pipe between 3 inches and 12 inches from each trap to conform with byelaws. Attempts have, of course, been made to improve on this system. One method is to install separate stacks for each kind of appliance, as in Fig. 2; reducing the number of appliances connected to any one stack enables ventilation pipework to be omitted from the waste side. This has some obvious