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 CONSTRUCTION OF HOUSES AND BARNS WITH REFERENCE TO HEALTHFULNESS Any liability to disease that may come from faulty construction of habitations is likely to spring from a polluted subsoil. Such pollution vitiates the air drawn from that soil and is a source of danger on account of the resulting impurity of the whole atmosphere within the house. Shutting out soil air. We have already seen (Chapter II) how it is possible for . soil charged with organic matter to deliver, either through suction from a heated house or on account of a rising ground water, soil air into the cellar, and also that moist air may enter the house in the same way. In order to prevent this, it is plainly necessary to interpose some airtight or water-tight layer between the house and the soil, and also, since perfection in this layer is impossible, to make provision for draining away any water which may accumulate against the walls. Ordinary builders do not lay much emphasis on the importance of either of these precautions, and while one may often see cellar walls roughly and carelessly coated on the outside, with tar or asphalt, a thoroughly water-tight coating is not a common practice. Similarly, while draintile are often laid around a house, they are either laid so near the surface as to be useless or else they have no porous filling. To prevent moisture from entering the cellar, the first provision should be a tile drain (not less than four inches in diameter) laid completely around the house (see Fig. 5) on a grade of not less than six inches in one hun- DFtA/N + // DRAW S TO BROOK Off GULLY Fig. 5. — Exterior wall-drains. dred feet. This drain at its highest point ought to be one foot below the bottom of the concrete floor of the cellar, and more than this, o...