This section is from the book "The Principles And Practice Of Modern House-Construction", by G. Lister Sutcliffe. Also available from Amazon: How Your House Works: A Visual Guide to Understanding & Maintaining Your Home.
The cistern G, on the had flat, is of slate, and holds about 300 gallons. It supplies the water for the bath w.c l, and the hot service throughout the house. It is recommended that this cistern be removed, and a new galvanized-iron cistern of 1/8-inch plate, to hold 300 gallons. be fixed under the new dormer to take its place. This cistern must have a 1 1/2-inch overflow discharging on to the flat, and service-pipes must be led from it to supply the hot-water system, the cold-water tap of the bath, and all the sinks except that in the scullery. A stop-cock should be provided close to the cistern.
Under the closet m there is a lead lined cistern, supplying the w.c. N in the scullery, the sink R, the copper, and the sink s in the servants' hall. This cistern should, it is said, be replaced by a 100-gailon galvanized-iron tank, in in the new larder to supply the sink in the scullery.
The fourth cistern is shown at I, and is of cast-lead; it supplies the w.c. o in the vault, and the two sinks, t and U. In the rearranged system, these sinks will be supplied from the large cistern G; as the cistern at I is too low to flush the w.c. o properly, it is recommended that a new 50-gallon galvanized-iron tank be fixed at a higher level, and protected against frost by a wood casing packed with hair-felt.
It will be noticed that galvanized-iron cisterns are recommended, but it must not be forgotten that the house under consideration is supposed to be a London house, and that the water in use in London is hard, and consequently has not much effect on the zinc coating. Soft water decomposes the zinc. This metal is not, however, by any means as harmful to the human system as lead, and the objection to galvanized cisterns is not therefore as strong as to cisterns lined with lead. Attention to the danger of lead-lined cisterns is drawn by the Commissioners in the following words: - "Lead should never be used to line cisterns in which potable water is to be stored, even when the pipes that lead to the sinks may safely be of lead. A piece of bright lead suspended in water or exposed to the air is quickly tarnished from the formation of a film, primarily of lead oxyhydrate. This oxide is soluble in water to a limited extent Fortunately London waters are hard, and mostly contain considerable quantities of sulphate and carbonate of lime, and form a protective coating of carbonate of lead, which is insoluble in water unless it contains an excess of CO2." It is somewhat strange that the Commissioners, after stating, as quoted above, that "lead should never be used to line cisterns in which potable water is to he stored", should go on to say that "where an old lead cistern is retained, it should be coated with a cement that will prevent the contact of the water". Such a coating cannot be expected to be permanent.
For the sake of readers in other parts of the country, it should be repeated that soft water, and particularly moorland water, often has a very rapid solvent effect on lead. In Oldham. and in many towns in the West Riding of Yorkshire, a vast amount of sickness and many premature deaths have been due to this If the water supplied by the public authority be of this nature, and be the only supply available, the only remedy for the consumer is to remove all lead water-pipes and cisterns from his house, and to substitute tin-lined wrought-iron pipes, or the "Eureka" tin-lined lead pipes (in which an inner tube of tin is separated from the outer tube of lead by a tube of asbestos), and galvanized-iron, slate, or earthenware cisterns; if the supply is constant, cisterns should only be used for the hot-water system and for the water-closets. The Commissioners recommend that the large lead service-pipes be removed, and a 3/4-inch lead pipe be laid to the new cisterns, a 3/4-inch screw-down high-pressure stop-cock being inserted in the area, and a ball-valve in each cistern. All pipes exposed in the area, cellar, and roof should be wrapped with hair-felt bound with copper wire.
Nothing is said as to the use of other metals than lead for pipes, although this is a most important question when the water has a solvent action on lead.
When this is the case, either tin-lined wrought-iron pipes must be used, or the
"Eureka" tin-lined lead pipe; in either case the joints must be made by means of special fittings adapted for the pipes. The methods of forming joints and blanches in tin-lined wrought-iron pipes have been illustrated and described on page 233, vol. i. A joint in Clarke's "Eureka" pipe must be made as shown in Fig. 693; the lead and asbestos must be removed from the end of one pipe for about an inch, and the end of the other pipe must be expanded to receive the projecting tube of tin; when the ends have been brought close together, a "wiped" solder joint must be made in the usual way. The branch-joint requires a special T-piece. as shown in Fig. 694, and more labour; the pipe receiving the branch must be sawn in two. and the two ends thus made, A and
Fig. 690. - Straight-joint in the "Eureka" Tin-lined Lead Pipe.
B, and also the end of the branch-pipe C, must be expanded to receive the projecting tin of the T-piece; when all the ends have been brought close together, the joint can be wiped in the usual way at one operation. Lead pipes washed with tin inside are worse than ordinary lead pipes, and should on DO account be used.
The water-closets are next considered by the Commissioners. The position of that on the third floor is bad, the reason given being that it is "unprovided with any means of Light or ventilation, except on to the staircase". The one valid objection to the position is that it necessitates an internal soil-pipe; both light and ventilation could easily be obtained through the roof. The Commissioners rightly recommend the removal of the closet to the back of the building, where a window can be obtained, and the soil-pipe fixed outside the wall. By the removal of the closet k on the second floor and M on the ground-floor, one soil-pipe is made to serve the three closets; this is an excellent arrangement The two closets N and O in the basement are both altered for convenience of drainage, a further objection to that marked N being that it is in direct communication with the scullery. The Commissioners rightly remark that "no closet should ever be fixed in a room that communicates directly with another room where food is either prepared or stored; the closet must always be divided from such room by an inclosed lobby, which, as well as the closet, must have direct communication with the external air by either door or window ".