CHAPTER V. SEWERAGE AND DRAINAQK (Part 4)

dry; and that when you lay a perfectly water-tight drain this subsoil water can no longer find vent, and may rise in the floors and up the walls, causing damp and illness, so that your new drain may do more harm than good. Tou must also not be deceived by a dry appearance of subsoil in fine weather, for when a rainy month comes the water may rise. It will be safe to lay, at a little distance from your new impervious drain, a run of common field drain, with open joints, surrounded by gravel, from back to front, or around the house, always freely open to the air at both ends, back and front, so that any water coming after you leave may by provided for. But you must be very careful never on any terms to connect this open-joint drain with the house drain. You must devise, according to circumstances, a safety disconnecting receiver, or water-trap, in open air, so arranged that, if it should ever run dry, the drain air could not possibly be drawn in through the subsoil drain. There should be a long ventilating grating between the water-trap and the drain, open freely to the air. liemember that you only place the trap and drain as a precaution against subsoil water, which may or may not appear, and you must deal with your subsoil drain accordingly; also remember that air always seeks to enter the house through the subsoil Very frequently wells are found in or near houses, in which, if disused, owing to a constant town supply being laid on, water may rise and overflow and saturate the base- ment, unless some provision for subsoil drainage be made SEWERAGE AND DRAINAGE. 159 such as has been described. The common field drain, sur- rounded by gravel, will be found safer and cheaper than any combined form of drain for the purpose. The junctions of house-pipes, soil-pipes, waste-pipes, etc., with drains, are very important. The earthenware drains should end outside the house wall if possible, and have a bend always turned upwards to receive the metal or lead house-pipes, which should never enter a drain horizontally. Even when the drain must' pass through a house, the junc- tions with it should all be effected outside the house wall in open air spaces, and always be carefully made. If plumbers are to be entrusted with a control over house drains, they should give proof, both to the public, to archi- tects, and to engineers, of their ability to form a true esti- mate of the importance of such work, and of the serious responsibility involved in the charge. Drainage should be treated, not as a secondary matter, but as a question con- cerning life and death. If the undergroimd drainage of a dwelling be imperfect outbreaks of disease will occur and recur, no matter how perfect that house may be in all other respects. The per- fection of any drain depends on the perfection of every part, so that the best and strongest material should be employed for the construction of a drain, especially when it must be laid through and under some portion of the house, as in the case of streets and terraces. Cast-iron drain-pipes of the weight and description constantly made for high-pressure water-mains for towns are now being used with great advantage for house drainage. Cast-iron drains must be heavy and soundly cast, and cast in the upright position, and should be proved under not less than three hundred pounds per square inch hydraulic pres- sure ; they should be straight, smooth, and truly circular in 160 DOMESTIC SANITARY DRAINAGE AND PLUMBING. bore, results much more easily attained with east metal than earthenware. Every connection now made in earthenware can be pro- duced better and quicker in cast iron. The models cost some money, but so do the models for earthenware. We have experienced annoyance and loss, caused by the delays in obtaining from the potteries earthenware drain connec- tions, and especially of any new forms, owing to unexpected failures in the kiln. No doubt we can obtain almost every form of useful connection in earthenware, but this will soon also be the case with cast iron as it comes more into use. In all cases where pipes are cut across to fit lei^ths they should be cut even, to prevent gaskin or lead being driven inside the pipe ; if cut irregularly, the pipe should not be used. In laying cast-iron drains the cost of concrete founda- tions and concrete filling round drain, which is considered necessary for earthenware drains, together with the extra excavation for such concrete, is all saved, and may be carried to the credit of the extra cost of the cast-iron drain, helping to equalise its ultimate cost, when laid, as compared with the earthenware drain. Each lead joint of a cast-iron drain costs more than a cement joint, but as the iron drain is in 9-feet lengths, one joint absolutely perfect takes the place of three or four joints of a doubtful character in the earthenware drains, and thus the cost is equalised, while the character of the jointing is incomparably improved. Cast-iron drains may be laid, jointed, and filled in as fast as the trench can be opened and levelled to receive them, often a matter of great importance and sometimes a great saving of expense, as, in case of wet weather when running drains through friable soils, the earth is liable to fall in before the cement in earthenware pipe-joints has time to set. SEWERAGE AND DRAINAGE. 161 Cast-iron drains may be safely laid close under or even above the surface of the ground, saving labour in excavation, besides preventing the dangers always attendant on conceal- ment of work, and often securing a more rapid fall. It often proves most useful to be able to joint two 9-feet or 6-feet lengths of iron drain together, in order to push or draw them through a tunnel, or under some porch or wine- cellar, whose floor cannot be disturbed to allow workmen the space necessary to make the joints of earthenware drains. Cast-iron drains are not only the strongest and safest, but they are undoubtedly the most suitable drains for plumbers to work and lay down. It is needful to remind workmen D 1 Fig. 48. — Cast-iron drain-i)ipe8. to make their molten lead sufl&ciently hot to ensure its run- ning thoroughly round and filling the socket ; if poured on only at melting point it solidifies quickly, and does not run well. Heavy cast-iron drains and all necessary connections are now made four, five, and six inches in diameter. The pipes are made in 9-feet, 6-feet, and 3-feet lengths, and in all intermediate sizes, or the lengths may be chipped round and cut to size with extreme nicety; and the cut lengths can generally be utilised with double sockets or slip collar-joints, preserving accurately the smooth internal bore of the drain. Every pipe and connection should, while still hot from casting, be coated inside and outside with M 162 DOMESTIC SANITARY DRAINAGE AND PLUMBING. Dr. Angus Smith's Preservative Composition, formed of pitch, tar, and linseed oil, well melted and mixed. This will prevent corrosion while it lasts, and can be reapplied at any time to the interior of the drain, by brushes made for the purpose. The writer has tried the Bower-Barflf process without success, as blisters of oxide appeared ; he much prefers the cheaper process above named. The joints of cast-iron drains are best when formed with socket and spigot, with projecting ring of metal inside and out respectively, bored and turned in a lathe, so as to form a water-tight joint when pressed together. In making the joints permanently under houses, tarred gaskin or rope yam should be driven tightly home round the socket, a temporary mould of clay then formed round the mouth of the socket, and very hot molten lead poured in through a hole left in top of the clay mould ; the clay is removed and the lead well batted and driven tight by the hammer and packing punch or calking tool all roimd the socket, care being always taken that the socket pipe is rigidly fixed, so as not to be driven back from the spigot by the blows from the hammer. Bends and connections cannot easily have their spigots and sockets turned and bored in lathes, so that these joints must be formed with yarn and molten lead well batted, par- ticular care being taken not to drive the socket away before the hammer. The ordinary well-known iron-rust joints may also be used, and relied upon, with cast-iron drain-pipes. The weight or strength of iron drains, when run under- ground, may be — for 3-inch, 12 lbs.; 4-inch, 18 lbs.; 5-inch, 25 lbs. ; 6 inch, 32 lbs. per lineal foot. Iron drains come well within the plumber's grasp, and he may claim the laying of them as his right, rather than, as in the case of earthenware drains, a concession or a con- venience. SEWERAGE AND DRAINAGE. 163 It is a decided advantage, in cases where the plumber has the drains under his control and care, that the materials should be such as he has been trained to work with. Cast-iron possesses other advantages over earthenware drains. Iron drains can be taken up safe and sound, and both pipes and lead joints can be used again in other posi- tions, or, if not longer required, are value as old metal and old lead. Earthenware drains, we know, when examined are generally found to be already fractured, or must be broken up for removal as valueless rubbish. Sound earthenware drains are often destroyed by having holes broken into them in order to join on a branch drain. Fio. 49.— Cast-iron bend. Fio. 50.— Cast-iron short bends. or to test the pipes, and they are then covered in and left working in that dangerous condition. Plumbers are frequently directed to do this when owners cannot wait for new drains to be laid, and receive blame unjustly afterwards when the drain comes to be relaid. This danger is not likely to occur with cast-iron drains, for it will be easier to provide proper junctions than to drill or cut holes in the iron drain. Cast-iron manhole chambers, with cast-iron intercepting traps and cast-iron air-tight covers and frames, are provided to intercept or cut ofiF all sewer or cesspool air from the house drain, and cast-iron manhole chambers or inspection openings should be used at every point where a change of 164 DOMESTIC SANITARY DRAINAGE AND PLUMBING. direction or gradient of drain occurs. These manhole chambers and inspection openings may be carried up water- tight to the surface, and are valuable as enabling a complete system of water-tight drains to be laid in positions liable to flooding or backwater from tides. The outfall mouth of drain, if guarded by a water-tight flap- valve, will render the system impervious to backwater, or flooding, or subsoil waters. Iron or earthenware drains for dwellings should be laid in straight lines, and with even gradients from point to point. Fio. 51. — Cast-iron manhole chamber bottoms. Five-inch diameter iron drains for dwellings should be laid with a fall of one foot in every fifty or fifty-four feet, the latter being two inches of fall in each 9-feet length of drain. In every case bends, junctions, and channels across manholes should have a fall of a quarter to half an inch in every foot, accenting the fall in all bends to compensate for and overcome increase of friction. In laying all kinds of drains always provide inspection openings and splayed jimctions, arranged for easy access, to cleanse the drain in every part by drain-clearing SEWERAGE AND DRAINAGE. 165 appliances without necessitating the opening of the ground. None of these access openings should be placed inside the house. >^ Fig. 62. — Cast-iron access pipe. Fig. 53. — Cast-iron inspection tee- piece. All new house drains should be tested by the hydraulic test before being passed as sound or covered in, and it is now usual to require a second test after the filling in of trenches is completed. Fio. 64. — Cast-iron splayed junction. Reducing pieces are made in two ways, both illustrated. In one the slope is made equal all round ; in the other, all the slope is thrown on the top of the reducer, so as to Fig. 55. — Equal slope reducer. Fio, 66.— Top slope reducer. ensure a level waterway — an important consideration, when reducing a large drain to suit a smaller interceptor outside. 166 DOMESTIC SANITARY DKAINAGE AND PLUMBING. Slip ferrules, or thimbles, are made to connect two cut pipes as shown. E3 Fio. 67.— Six-inch ferrnle. Fio. 68. — Four-inch ferrule. Cast-iron interceptors and traps and cast-iron safety dis- connecting receivers for waste-pipes are also necessary. Fio. 69. — Iron interceptor. Fio. 60.— Iron syphon. Fio. 61.— Iron syphon. Fio. 62. — Iron disconnector. Fio. 68.— Iron receiver. The interception of house drains from the sewers may be very simply and efifectually done by any good form of trap on the drain which admits of easy access for cleaning and inspection, has free ventilation to open air and to house drain, and shows the house drainage flowing through, and is small enough to clear with two-gallon flush. The running trap form of interceptor does not fulfil these re- SEWERAGE AND DRAINAGE. 167 quirements. If it be provided with a cleaning eye or pipe the house drainage cannot be seen passing, but the solids FRESH AIR INLET C AIR TfCHT IRON COVER f^ fr I m II I i^y^ III ^ , I , , , ■- ^\ I I -r Fio. 64. — Manhole intercepting chamber, with fresh-air inlet. Fig. 65. — Section showing arrangement of manhole chamber, intercepting trap, fresh-air inlet, vent-shafts, soil-pipes, bath and trough pipes, and vent-pipes. float up into the eye, and there decompose dangerously. Frequently the drain runs so deep down at the outgo in area that no trap can be reached. A manhole chamber then 168 DOMESTIC SANITARY DRAINAGE AND PLUMBING. becomes a necessity, as it is at all times the best and only satisfactory arrangement. It should be in the open air, about 3 feet x 2 feet, or any convenient size regulated by circumstances ; the walls, built of 4J-inch or 9-inch brick- work, may be cemented inside, or merely pointed in the joints. The manhole chambers near a dwelling-house should be rendered as staunch, and hold water as securely, as the drain itself. The house drain enters the house side on the bottom, so that, by stooping down, you can look right Fio. 66. — Plan of manhole chamber, showing eight separate branch drains joining main drain at various angles. through the drain to a corresponding manhole in backyard. You should see that it is smooth and level and clean throughout, and you can put a brush or scraper right through for cleansing purposes. It is much the best plan, if you have any other branch pipes or drains inside the house, to lead them also straight into the front or back manhole, so that you can also look through and cleanse them. It is not well to join these drains, or to make any connection into the house drain, as it passes from the back to the front manholes ; it should come through intact, if possible. From the main house drain, eicross the bottom of the manhole chamber, a SEWERAGE AND DRAINAGE. 169 groove or channel (half a drain-pipe cut through longitudi- nally will do, if you have nothing better) sliould be laid in cement to the back of interceptor trap set at opposite side of chamber in connection witli main branch to sewer. Fig. 67. — Manhole chamber ; short right-angle bend, 14-inch radius on centre line. Fio. 68. — Manhole chamber; long right-angle bend, 18-inch radius on centre line. The bottoms of these chambers should be sloped in cement, to prevent deposit of any foul matters. These may all, be made into intercepting chambers by using any suitable interceptor trap at the outgo end. R -^^-^ — . . - ii*-^- ■ A ■ 'rr^ 'M^0^^ ■ '0^^ :/^^'^ ■ I m ■ '■ '^ ^- 1 m Fig. 69. — Manhole chamber ; short obtuse-angle bend, 24-inch ra lius on centre line. Fig. 70. — Manhole chamber; long obtuse-angle bend, 33-inch radius on centi-e line. 170 DOMESTIC SANITARY DRAINAGE AND PLUMBING. Fig. 71. — Manhole chamber ; long curve, 48 -inch radius on centre line. Interceptors should be partly in the cham- ber, and 80 arranged as to be seen and cleaned with ease. A splay junction pipe should Ije carried back from the drain beyond the interceptor into the wall of the cham- ber, througli which the outer drain could be cleared, in event of stoppage, without pulling up the drain. This cleaning pipe must, of course, be closed air-tight, for, if left open, sewer air would pass into house drain. It would be better and safer to end it outside the chamber in the open air, so that no accident from neglect should be possible. Other branch drains from house and area may be delivered into manhole just above the level of the groove or channel, but so arranged that no flooding back of other drains can occur, all water, etc., passing easily and directly into the interceptor and away, and so that no deposit whatever can remain. The bottom of the chamber, up to tlie sides of the channels, to he smoothly cemented, with a quick slope towards the main channel. The interior of such chambers should always present, when inspected, a smooth and perfectly clean and pure appearance. The ventilation of the manhole chambers is all-important. It is always essential to secure thorough disconnection of the bath and trough