In the building of a house the foundation must receive just consideration. As the foundation holds the entire structure, such material must be used as to give adequate support to this weight. Care must be exercised in the evacuations that the basement be protected from dampness and that the entire site beneath the foundation be properly drained. The ground water should be ten feet beneath the surface of the site.
It is recommended by some hygienists that the basement floor be of cement six inches thick to prevent the entrance of ground air and moisture. This should be covered with a wood floor.
The preparation of the foundation is comparatively easy where the ground is solid, but if the site be water-logged, marshy, quicksand, or entirely under water, its preparation then becomes a problem that may baffle the best engineers. Artificial foundation beds may have to be resorted to. These are accomplished in several ways. One very common method is to drive wooden piles into the ground, saw off the tops and construct the foundation on these piles. Another method is that of the cofferdam.
The foundation having been properly prepared, care must be taken that the footings or base course of the walls are of sufficient strength to bear the weight of the superstructure. The footings should be of stone or concrete and should be a little thicker than the walls.
Precautions for a dry basement must also be considered. This subject will be discussed under House Dampness.
The air of the basement must be kept pure by proper ventilation, since it is being constantly drawn up into the house. This will receive some attention in the chapter on Ventilation.
Walls
The walls of the house may be of brick, stone, timber or concrete. The method of construction will depend upon the material used. If timber is utilized the security of the walls will be governed by the timber posts, sills and plates. The materials used should be as little absorbent of moisture as possible. All wood should be well seasoned.
Floors
In order to meet all sanitary requirements the “floors must be secure and proof against air, dust, sound, vermin, fire and water.” But it is not often that the floors meet all these sanitary demands. Ordinary floors are made of hard boards tongued and grooved, tightly fitted and laid upon joists placed about one foot apart; the under surface is lathed and plastered to form the ceiling of the room below, or some sort of patent ceiling may be used. However, there is great objection to the space thus left between the floor and the ceiling, as it becomes a receptacle for dust and greatly endangers the spread of fire.