Purchase of this book includes free trial access to www.million-books.com where you can read more than a million books for free. This is an OCR edition with typos. Excerpt from book: CHAPTER III. Inside Sewers. 11J EAVY cast, iron pipes, having weights corresponding to those shown in Table 2, are the only materials considered to be suitable and safe for the sewers on the inside of a building and for a distance of at least three feet outside the foundation walls. Earthenware pipes are not considered safe for this purpose because of their liability to be broken by the settling of the walls of buildings under which they would have to pass. Where the acid wastes of a laboratory, or any sewage containing strong acids in sufficient amount to injure an iron sewer, are to be removed it would be necessary to make use of earthenware pipes, in which case only the best quality of pipes should be used, and, when laid and jointed, should be encased in a substantial ring of cement concrete, and relieving arches built over each opening in the walls through which the pipes may have to pass. The latter precaution might be observed with advantage where the sewer is constructed of extra heavy cast iron pipes, particularly in the case of buildings of considerable height and in new buildings which have not got through settling. SIZE AND INCLINATION. The size and inclination will be governed largely by the size and inclination of the outside portion of the sewer, the methods of determination of which are explained in Chapter II. A size of less than four inches is not desirable, and a four-inch sewer will be large enough for the inside sewer of any ordinary building. UNDERGROUND VS. HANGING PIPES. Wherever possible the laying of a sewer under the basement floor of a building should be avoided and the soil and waste pipes run on the walls or ceilings of the basement to the point where the sewer enters the building. Where the sewer must be laid under the floors care sho...