It is better, according to sanitary demands, to have the floor of reinforced concrete, or the space within filled with mineral wool or asbestos; or the floor may be made of steel beams encased in terra-cotta with interspaces made of concrete.
Roof
For roofing some non-absorbent material is best. Wood shingles are possibly the most common in this country, although they are rapidly being replaced with composition shingles. The wood shingles are somewhat absorbent and are inflammable. Slate and tile are also used. The slate is a good conductor of heat, and is hot in summer and cold in winter. Tiles are heavy but are warm in winter and cool in summer. Lead, zinc and copper have all been used, but they are good conductors of heat and for various other reasons are not exactly desirable. The best method of preventing too rapid conduction of heat is to have an air space between the roof and the ceiling of the top floor.
House Dampness
Great care should be exercised to prevent the entrance of moisture into the house. A damp house is very objectionable. In a newly constructed building there is always more or less dampness coming from green lumber, mortar and plaster. This is known as building water. Before a new house is occupied it should be thoroughly dried by a fire in stoves or furnaces. Dampness from building water is only temporary and easily eliminated.
Moisture in houses from damp sites, leaky drains, porous building material which admits rain and other similar causes, require the attention of an engineer who understands water-proof construction.
Moisture from the ground water may ascend the walls of the building by capillary attraction. This may be prevented by properly draining the site and by placing a horizontal water-proof course in the walls. This may consist of asphalt one-half inch thick or a course of slate or other material through which the moisture will not penetrate.
The ill effects of a damp house upon the health of the occupants can hardly be overestimated. Such houses are cold, being difficult to heat and ventilate. The bodily heat is too rapidly withdrawn. This necessitates adaptative action on the part of Innate Intelligence and requires an unnecessary expenditure of internal energy.
Aside from a damp house having an ill effect upon health by creating an environment which is not conducive to the expression of life indoors, the dampness tends to produce moulds and otherwise injure the furniture and hangings. This results in a musty odor and creates a condition conducive to the development of cockroaches and water bugs. These conditions are repulsive to the finer sensibilities.
It is a recognized fact that Innate Intelligence is able to adapt the body to various conditions and people who appear to be in a state of comparatively good health may be found in such environments, but why should we force Innate to adapt the body to such adverse conditions when we may educationally improve the surroundings and make them more healthful? The educated mind is the expression of the same Innate Intelligence that is adapting the body to the environment, so it is only reasonable that the educated mind should be used in as intelligent a manner as the Innate mind. It is the function of the educated mind to bring about an educated adaptation to the environment through the educated body and to study the laws of nature and adapt them to the needs of the body.