A fireproofing material for application to flammable surfaces is based on an alkali metal silicate solution containing a non-ionic surfactant in combination with an alkali metal tri-silicate powder. The composition according to the invention is easily applicable to plane surfaces with ordinary tools, for example, spatulas, yet will not run either when applied or when subjected to flame.

Materials variously treated with sodium silicate were studied until enough information was obtained to find a way to solve the problems that have prevented sodium silicate from being the used as a fire retardant. These problems are: 1) water solubility (miscible with water), which results in extensive leaching when exposed to water, 2) cracking, chipping and peeling of treated surfaces, and 3) surface granulation. During flame tests it was discovered that sodium silicate formed a foam-like material, and this material was found to have become water insoluble, yet its elemental composition had remained virtually identical to that of the unmodified sodium silicate. This investigator proposes that under the influence of heat and dehydration, sodium silicate undergoes a polymerization process resulting in particles sizes too large to dissolve in water, and then developed a mechanism to explain how the process could occur. The temperature and moisture conditions in treated samples were then manipulated to cause the polymerization process to occur while protecting the wood from damage. Thus samples were prepared that were both water insoluble, and possessed effective fire retardant properties. These samples also proved to be stronger than untreated wood, thus providing an improved product that was fire retardant and moisture resistant. Since aqueous sodium silicate can be combined with other inorganic fire retardants, this technique is a potential method for making any inorganic fire retardants moisture resistant. This represents a potential breakthrough in fire retardants that has been sought for approximately 100 years. In addition, sodium silicate treated samples were made moisture resistant by the application of a micro-thin layer of silicon monoxide to the surface of samples. This technique, also never tried before, represents a second method for providing moisture resistant, fire retardant substances.

Wood products, specifically wood commonly used in construction including dimension lumber, pressure treated pine, composite wood materials such as plywood, particle board, and wafer board, and samples of paper and fabric were variously treated with concentrations of sodium silicate (Na.sub.2OSiO.sub.2) also known as water glass. Cellulosic materials including dimension lumber, plywood, particle board, wafer board, paper, and fabric were treated with sodium silicate (Na2O.SiO2) in concentrations ranging from 400-0.04 g Na2O.SiO2/kg water. To overcome the disadvantages of sodium silicate, sodium silicate treated samples were further treated to convert the water soluble sodium silicate to a water insoluble form, thereby overcoming the disadvantages of water solubility. and rendering the material effective for internal and external uses. Although treated sodium silicate samples are composed of the same elements in similar proportions, as the untreated sodium silicate samples, the water solubility of the treated and untreated substances is very different.