COMMERCIAL FIREPROOFING OF WOOD The fireproofing of wood on a commercial scale is thus described by Mr. F. C. Schmitz, Vice-President of the Standard Wood Treating Company, New York, N. Y.: The fireproofing of wood, as at present practiced commercially, is accomplished by saturating its fibers with a water solution of chemicals which, in the presence of fire, emit a gas that prevents combustion. To accomplish this, the wood. to be treated is loaded on suitable cars, and placed in a cylinder from which the air is exhausted. The above-mentioned solution is then let into and completely fills the cylinder. Hydraulic pressure is then applied, by means of a pump, of such a degree and for sufficient time to force the chemical solution into and through the wood, to the point of saturation. Upon reaching this latter point, the cylinder is drained of solution, and the lumber removed.
When it is necessary that the treated lumber shall be thoroughly dry before it can be used, it is kiln-dried to evaporate the water in the solution, leaving the chemicals in the pores of the wood in dry crystal form.
It is not claimed for the product that it is fireproof in the sense of being, like firebrick, indestructible in the presence of fire, but that it will not support or communicate combustion. Any organic substance will be destroyed by fire if left in its presence for a sufficient length of time.
An important fact in connection with the use of fireproof wood, is that it is fireproofed with water-soluble chemicals; and therefore, if, after treatment, it is exposed to water (such as rain), the chemicals again dissolve and are removed from the wood, with a consequent reduction in its resistance to fire. Any wood, therefore, intended for outside use, should be protected from the weather by a waterproof coating, such as paint or varnish.
Fireproof wood has been used largely for interior work, and principally in the city of New York, where the Building Code provides for its use in all buildings over 150 feet or twelve stories in height. It has, however, had a considerable use in residences and in various trades, for special purposes.
The treatment is permanent so long as no water is permitted to soak into the wood; and samples taken from buildings after fifteen years' service show as good results as freshly treated lumber. The treatment slightly hardens and in some cases darkens the wood. It does not, however, affect its strength or impair its beauty.
The process is comparatively inexpensive, when results are considered; and ultimately its use must be widespread, especially in isolated buildings where fire-fighting facilities are not of the best, and where fire would result in large damage to business.
Many corporations and firms in the East are now beginning to realize this point, and there is a constantly increasing demand for the product for such uses.