To Conduct Test On Plaster Lath

With the definite purpose of setting practical and permanent standards for gypsum-centered plaster lath, product of the $1,000,000 Southern California plaster board industry, an exhaustive program of research, fire tests and unit stress experiments has just been launched, according to J. F. Kiefaber, member of the General Committee of Plaster Board Industries. These experime'nts will be conducted by a special testing laboratory at the University of Southern California, under the direction of Professor R. M. Fox, head of the university civil engineering clepartment.

"Due to the fact that the Los Angeles plaiter board industry has increased in size and volume of production so rapidly during the past few years, we have bein faced with a shortage of data ahd research information regarding the tensile strength, fire resisting qualities and adaptable uses of our products," Mr. Kiefaber said. .This ihortage is existing principally because we have not had. the tirie to devote to experimentation and compilation of statistics. However, a definite program of research is now under wav at last, and the first official data on the fire-resisting chaiacteristics of plaster lath is now available.,,

This first information is the report made by Lieut, F. E. Walker of the Los Angeles Fire Department to Fire Chief Scott on the remarkable performance of the products in the recent conflagration at the United Studios. The report follor,l's, in part:-

"Plaster lath on the walls of the cutting room of the United Studios, contained the fire within the room and prevented its spread to adjoining frame buildings. The blaze began wheh a spark ignited a bit of waste film. Owing to the highly inflammable character of the contents of the room, the fire gained rapid headway.

"f made an investigation shortly after the conflagration and discovered the effects of the intense heat upon the rnaterials. The door had been closed and thus draughts were cut to a minimum. The heat was of such high tensity that it permeated the interstices of the walling. The trapped smoke and flames generated gasses which forced the walls outward until the room had the physical aspects of an inflated box. The pressure upon the door became so great that it was lifted from its moorings and hurtled through the air for a distance of ten feet. Flames which leaped through this aperture scorched a telephone pole twenty feet away.

"I made a thorough investigation after the fire had spent itself and the room was still hot. The plaster board and plaster lath was intact. The fact is unusually significant and attributes to the high fire-resistant qualities of the material in view of the rather surprising fact that the heat had been so intense that metal parts of all machinery in the room had been melted down. A projector, which I examined, was entirely bereft of its steel trappings, which lay at the base of the machine in a shapeless mass.

"This striking instahce of the value of gypsum-centered plaster lath as a fire-resister will be utilized by us as the basis of further tests to determine the full extent of the unusual strength in the face of heat, gasses and flames."