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 cutting of socket hole for the purpose of giving the barrel of the pipes a continuous rest upon a firm foundation is very seldom performed except and closest supervision, nor is the puddle band tarried completely round the pipe under the invert; and as much of this class of work is done by contract. or the labour performed by piece-work, it is hardly to be expected that drains so laid will continue water-tight.
The question of jointing earthenware pipes has always been one presenting great difficulty, and the material used for jointing is of great importance. It is generally common lime mortar, or mortar made of some more or less hydraulic lime or cement. For any purpose which implies contact with water, as a drain does, common lime is quite unfitted. It is readily worn away, and has not that closeness of texture needed to render it impervious both to water and gases While hydraulic limes are of course better than common limes, their use and the saving supposed to be effected by them cannot be weighed with the advantag gained by using cement. Without making any comparisons between the relative merits of Roman and Portland cement, it should be admitted at once that a joint made with Portland cement and sand is a right one, subject to certain conditions: - there must be only one part of sand to 4 parts of Portland cement, and care must be taken that the sand is free from dirt, earth, or clay, and that it is sharp but not coarse in the grain. As ordinarily made. - that is, with improper sand and inferior cement or lime, and improper proportions, the joint is quite as objectionable as the clay joint, not only from defects of material, but also of workmanship.
We have already pointed out that there is a space between the spigot and the socket of adjacent pipes when the spigot is driven home, and in making the joint, the spigot should be properly Bet up in the socket so as to get a true alignment of invert, and so that the whole space around the spigot may be evenly filled. Generally speaking, the lalbourer intrusted with this work takes care to plaster plenty of cement on the top of the pipe, where it can be seen, but a close examination will often prove that the invert is entirely bare, and that the spigot has not been set up. A reference to Fig. 315 will show how pipes are generally laid, revealing the spigot in contact with the socket at the invert.
Another great objection to joints made in this way is that the cement is usually applied in too moist a condition, and there being nothing to resist its progress, it travels down to the invert, rises up through the joint, and there sets in a ridge, forming an obstruction to the flow of sewage, as shown in Fig. 316. Jointing by this method is not to be commended, but if it is adopted there must be rigid insistence upon the proper setting up of tin-spigot in the socket, and true alignment of the inverts, and the pipe-layer, should he fail to accomplish thus, must withdraw the pipe and procure one that will fit accurately. Care must be bestowed upon the proper mixing of the cement so that it will set easily without displacement, which may be caused by blows from the men working in the trench or in the refilling of the earth.
Fig. 315 -Faulty Drain-pipe Join Bad Alignment.
The pipe-layer should always be provided with the tool which is known to the men as "the badger", with which to wipe out the inside of the joint after it is run. This tool may be formed of a disc of wood of slightly less diameter than the pipe, having on its edge a narrow slip of india-rubber. The disc should be secured to a wooden haft of a length equal to the length of a pipe and a half. The disc should lie in the barrel of the pipe last laid, and the pipe about to be laid should be passed over the handle and properly centred and set up; then alter the joint is made, the badger should be pulled forward across the joint, from which it wipes away any protruding cement which has projected through in the interstices. Quite recently an improved badger has been introduced by Mr. Fred Lynde, A.M.I.C.E., which consists of two discs formed of hard wood edged with india-rubber, the discs connected together by a spiral steel spring which enables the tool to be drawn through bends. This badger is illustrated in Fig. 317.
To make a sound cement joint, the space around the spigot, after centring and setting up the pipes, should be filled with strands of tarred gasket, which most be driven home to the rebate of the socket, the work being done with a proper caulking tool of hardest steel cranked for hand hold, with a flat face l 1/8 inches x 5/16 inch. The band of tarred gasket will prevent any of the cement from passing through the joint, and. being imprervious, is not liable to rot although in contact with the moist cement To make the joint properly, a hole in the bottom of the trench should be made in front of each socket to give the joint -maker room to work in. The cement should form a fillet projecting beyond the socket to a distance equal to the thickness of the socket, and be neatly levelled off to an angle of 45°. This joint is shown in Fig. 318. It is a most efficient one, and requires considerable skill and care, and although it costs more money than the somewhat loose and unsatisfactory method first described, it is well worth the extra expenditure. The cost of the tarred gasket is about 4d. per pound, and the weight required for a 6-inch pipe is 4 1/2 oz.,and for a 4-inch pipe 2 1/2 oz.; the amount of cement required for a 6-inch pipe is 2 1/3 lbs., and for a 4-inch pipe 1 1/3 lbs.; the time expended by the pipe-layer in laying, driving home, centring, setting up, caulking, and pointing the pipe, averages for a 6- inch pipe 5 2/3 minutes, and for a 4-inch pipe 2 1/3 minutes. These times do not include any work about the trench, or in lowering the pipes, which would of course be common to all types of pipes.
Fig. 316 - Faulty Drain-pipe Joint :-Ridge of Cement.
Fig. 317 - The "Loco" Drain -Badger.