This section is from the book "Modern Buildings, Their Planning, Construction And Equipment Vol2", by G. A. T. Middleton. Also available from Amazon: Modern Buildings.
The drains to be laid on a bed of Portland cement concrete 6 inches thick and 12 inches wider than the outside diameter of the pipe; each pipe to rest on a blue brick set in cement, and the concrete flaunched up to pipe.
Excavate for and lay the drains as shown on the drawings of the several diameters figured thereon, and to falls of not less than 1 in 40 for 4-inch drains, and 1 in 60 for 6-inch drains, unless otherwise indicated on the drawings, with all necessary bends, junctions, etc.
Provide and fix under all rain-water pipes, sink and bath wastes, etc., and where shown in yard, Bolding's or other approved gulley traps and 6-inch galvanised iron gratings with 4-inch outgoes, p.c. 8s. each, set on and including Portland cement concrete bed 6 inches thick at least, and properly connect to drain.
The traps under waste pipes to have side inlets for same.
Provide and fix on sewer side of disconnecting chamber a Winser's or other approved 6-inch disconnecting trap with cleaning arm and cap, and set on and including a cement concrete bed, and properly connect to drain and manhole, and put 3-inch self-faced York stone lintel over same in wall of manhole.
Excavate for and build the manholes of the several dimensions shown or figured on the drawings in 9 inches brickwork in cement with proper footings, and cement concrete bottom 9 inches thick at least, and benched up to channel pipes; render the sides and bottoms in cement and sand (2 to 1) 1 inch thick, finished with neat dry cement trowelled in on surface. Corbel out tops for and provide and fix Bolding's galvanised iron air-tight cover and frame, p.c. The grooves in frame to be filled with an approved mixture of tallow and oil. Cut all holes for pipes and make good. Provide and set in bottom of manholes, Winser's or other approved best white glazed channel pipes and three-quarter pipe bends, the bends to deliver over the top of main channel.
Where manholes are over 3 feet in depth provide and build in approved galvanised cast-iron horse-shoe foot irons 18 inches apart.
Excavate for and lay 4-inch drain pipe as described from top of disconnecting chamber for ventilator, with bend at end and short length of 4-inch stout galvanised cast-iron ventilating pipe fixed to oak plugs in brick joints, and with Bolding's or other approved open balance galvanised fresh-air inlet, p.c. , jointed to pipe with tow and red lead.
The whole of the drains are to be tested by water or other test as required at the expense of the builder, and approved by the architect before they are covered in, and again tested and approved after covering in, and all defects are to be made good.
Core out all drains, and leave the whole of the drainage clean and perfect at completion.
Attend upon, cut away for, and make good after all trades requiring it.