US2785099A - Fire resisting insulating material and building construction embodying the same - Google Patents

Description

March 12, 1957 E. L. HOLTSFORD 2,785,099

FIRE RESISTING INSULATING MATERIAL AND BUILDING CONSTRUCTION EMBODYING THE SAME Filed Sept. 5. 1950 2 She'ets-Sheet l INVENTOR. ff K657 1., H01 IZSFOKO March 1957 E. L. HOLTSFORD 2 785,099

FIRE RESISTING INSULATING MATERIAL. AND BUILDING Filed Sept. 5. 1950 CONSTRUCTION EMBODYING THE SAME 2 Sheets-Sheet 2 rawzmwee "F azxiussanumau.

TIME vm/ #0065 INVENTOR. ERA/57 L. l/OIJSFORD United States Patent FIRE RESISTING INSULATING MATERIAL AND BUILDING CONSTRUCTION EMBODYING THE SAME Ernest L. Holtsford, Birmingham, Ala., assignor to Badham Insulation Company, a corporation of Alabama Application September 5, 1950, Serial No. 183,266

2 Claims. (Cl. 154-44) My present invention relates to fire resistant insulating materials and building construction embodying the same, and more particularly to a material and construction which shall form a sound absorbing, fire resistant ceiling construction.

An object of my invention is to provide fire resistant wall or ceiling construction making use of bats or layers of non-inflammable fibrous material such as mineral wool, rock wool, or similar materials made of glass and the like, in combination with metallic foil so associated with the non-inflammable material as to make it more etfective in protecting the part of the building behind the wall or above the ceiling, and a construction which shall be effective to hold the temperature of part of the building behind or above the same below the maximum temperatures permitted by prescribed fire regulations.

A more specific object is to provide ceiling construction which shall be fire resistant as well as sound deadening, such construction embodying the usual fire resistant acoustical tile below and my improved fire resistant insulating material above.

Another object is to provide a combined fire resisting and acoustical ceiling in which the degree of fire resistance is increased by the provision of a sheet ofthin metal foil, preferably aluminum, spread on top of the acoustical tile with a layer of the wool-like insulating material on top of the sheet. Alternately, I may place the sheet of foil intermediate the upper and lower surfaces of the upper layer of fibrous material.

Another object is to provide a bat of non-inflammable fibrous material having secured either to the underside thereof or intermediate the thickness thereof a sheet of metal foil, thereby to decrease the transfer of heat through the bat.

A further object is to provide a bat of heat insulating material comprising a bat proper of non-inflammable mineral wool-like material having glued or otherwise secured to its under surface a sheet of metal foil which projects past one or more sides of the bat as the bat is viewed in plan, whereby when such bats are laid side by side the projecting lengths of foil bridge or cover the crack therebetween, adding to the fire resistance of the ceiling or wall in which such bats are placed.

Briefly, I have found that I can construct an acoustical ceiling which meets accepted fire tests by placing above the usual acoustical tile or the like an improved form of fire resisting material. This material consists essentially of low density bats or layers of non-inflammable fibers in combination with a thin sheet of metal foil. The physical relationship between the foil and the insulating material may take various forms. First, the metal foil may be laid directly on top of the acoustical tile and the non-inflammable material spread in loose form thereover.

Secondly, the foil sheets may be secured by a suitable adhesive or glue to the underside of a bat of the material, and the bat then laid with the foil sheet down, directly on top of the acoustical tile. Thirdly, the sheet of metal foil may be glued into the bat of material, intermediate its thickness, preferably nearer the bottom side than the upper side.

When a ceiling construction embodying my invention is subjected to a standard fire test, for instance the one prescribed by The American Society for Testing Materials, I find that it fully meets the requirements of such test. It appears that the sheet of foil not only spreads localized heat evenly throughout the hat or layer of material, but that if subjected to the temperature at which the foil oxidizes it binds the fibers of the bat together, preventing the bat from eroding. Thus, I have discovered that even when sections of the acoustical tile are eroded away due to high temperatures and/or flame action, the foil oxidizes and binds with the adjacent fibers of the bat or layer, resulting in lowering considerably the erosion effect of the heat and flame playing on the bat itself. Over such an area, therefore, my improved construction is highly effective in preventing the through passage of flame, thus protecting parts of the building above the ceiling.

My invention is illustrated in the accompanying drawings forming a part of this application in which:

Fig. 1 is a fragmental perspective view with certain parts in section and showing my invention associated with a ceiling having a lower layer of acoustical tile and suspended in one of the usual ways;

Fig. 2 is a sectional view taken generally along line II-II of Fig. 1;

Fig. 3 is a perspective view of the form of the improved fire resistant bat shown in Figs. 1 and 2, partly broken away and in section;

Fig. 4 is a graph illustrating the results of a test run on a ceiling section embodying the type of bat shown in Figs. 1, 2 and 3;

Fig. 5 is a plan view of a modified form of bat in which the sheet of foil material is secured to the bottom thereof; and,

Fig. 6 is a detail sectional view taken generally along line VIVI of Fig. 5.

Referring now to the drawings for a better understanding of my invention and more particularly to Figs. 1 to 3 thereof, I illustrate a ceiling construction which is both noise reducing and fire resistant. I have selected one form of suspension means for the acoustical tile, but it will be understood that various means are now known, for suspending the same from the superstructure above a ceiling. As shown, I illustrate a plurality of acoustical tile 10 which are grooved along their edges as at 11 in the customary manner. These tile usually are made of non-inflammable material such as rock-Wool, asbestos ol the like, and the lower surfaces thereof may be provided with a plurality of holes 12. The holes 12 extend partway through the tile, and the material surrounding the holes is of relatively low density. The material forming the tile 10 above the holes, while being of the same type of material as the material surrounding the holes, is relatively denser.

Fitting in the adjacent edgewise openings of the tile 10 are T-shaped runners 13. The runners 13 may be suspended from brackets 14 having an upper portion fitting over a small channel 16. The channels 16 are provided at intervals in the construction and are in turn supported by larger channels 17, fewer in number than the charm nels 16. The channels 17 may be supported in any suitable manner from the building-structure above'the ceiling, as for instance by means of the wires indicated at 18. Suflice it to say here that the tile may be suspended from the upper part of the building in any suitable way.

My invention consists in increasing the fire resisting qualities of such a ceiling construction by the provision of an improved form of fire resisting bat of material indicated generally by the numeral 191. As shown in Figs. 1, 2 and 3 the bat '19 maybe formed of fibrous material such as rock-wool, mineral wool, lead wool, glass wool and any of the other and well known suitable forms of material similar thereto with respect to density and flammability. The density of such materials varies-from about 2 /2 pounds per cubic foot to about 7' pounds per cubic foot. Preferably, the bat 19. may be of the usual x 27 inch size and 2 to 4 inches thick.

Approximately /2 inch up into the bat from the surface thereof adjacent the upper surface of. the tile 10 I secure in the hat a sheet of metal foil indicated. by the numeral 21. The foil preferably is dead soft aluminum on the order of .0007 to .0009 inch in thickness or a material having substantially the heat transfer characteristics of aluminum. In making the bat 191 may coat the upper and lower surfaces of the foil 21 with a suitable adhesive such for instance as an inorganic binder or adhesive like the water base silicates with refractory fillers ofsuch nature as to be capable of withstanding temperature on the order of 2000 F. A specific example of such material is sodium silicate with a magnesium oxide filler.

In constructing a wall embodying the type of bat shown in Figs. 1, 2 and 3, the runners 13 and the upper framework for supporting the ceilingisput up in the ordinary manner. As the tile 10 is put in place my improved bats may be laid directly on the tile, between the runners and beneath the channels 16. The bats 19 may be laid either as the ceiling is being constructed or they may be put in place after the ceiling is completely constructed.

At all events, they are placed so that they abut'along.

the sides and ends as closely as possible so as to leave as small a crack as possible therebetwecn.

In Fig. 4 I indicate the results of an actual test on a ceiling embodying the form of my invention shown in Figs. 1, 2 and 3. The curve 22 represents a standard temperature curve plotted against time and temperature for the test of a 2 inch mineral wool bat placed above inch thick non-combustible acoustical tile, The dotdash line 23 represents the maximum allowable backing temperature, namely the temperature on top of the but 19 or on the bottom of the buildingstructure above the bats. Curve 24 represents the actual test, run under standard conditions, of my improved bat in the form shown in Figs. 1, 2 and 3 when placed QVI% inch noncombustible acoustical tile. It will be seen that the curve 24 shows that the resistance to heat transmission of my improved ceiling construction is entirely adequate, and that it falls well below the maximum allowable for the times shown. In the type of bat represented by the curve 24, the material used was rock-wool having a density of 6 to 7 pounds per cubic foot. The foil was placed /2 inch from the bottom of the bat and consisted of a sheet of dead soft aluminum on the order of .0007' to .0009 inch in thickness.

Upon continuing to subject the ceiling construction shown by test curve 24 to increased temperatures, 1 found that eventually the acoustical tile 10 eroded away, exposing the lower surface of the bat 19. After a period of time the lower part of the bat 19 beneath the sheet 21 also eroded away. This permitted the sheet 21 to oxidize at the point where the flame was directly applied and in oxidizing the aluminum bonded to the fibers of the upper part of the bat adjacent thereto. The effect of this was to materially decrease furthererodingefiect on the fibrous materiaLeven though the flame continued to play on the same area. The combination of the oxidized aluminum and the fibers of the bat'was sutficient to bridge over the hole eroded away through the tile and lower part of the bat and to prevent the upper part of the bat 19 from falling therethrough.

In some instances I may prefer to place the strip or sheet 21a beneath the lower surface of the bats of material 19a indicated in Figs. 5; and 6. Also, in order to have sufficient of the foil material to assure that any cracks left between adjacent bats 19:: are covered I may permit the foil sheet to overhang the long sides of the bat as indicated at 26, thus to provide flaps. In placing the bats 19a I so lay them that the flaps 26 overlie one another, further excluding the penetration of flame through the ceiling structure. If desired, the sheet 21a may be adhesively secured to the lower surface of the bat 19a with one of the adhesives previously mentioned.

From the foregoing it will be apparent that I have devised an improved fire resisting material and an improved ceiling construction embodying the same. In actual practice I have found that my invention is particularly effective in equalizing the heat from a hot spot or hot area throughout the bat containing the foil sheet. Further, due to the shiny'surface of such foil material it is particularly effective in reflecting radiant heat, further lowering the temperature above the bats. My invention is economical and practical in every respect. The foil 21 or 21a may conveniently be of the type currently sold for household purposes, and hence is very inexpensive. The oxidizing temperature ofsuch aluminum is around 1300 F. to 2000 F. 'Its effect in'combination with the'ceiling structure shown in reflecting heat downwardly, in equalizing heat throughout the bat, and in combining when oxidized with the fibers of the bat adjacent thereto, all add together to make my improved construction far superior to any fire resistant ceiling with which I am familiar. In the appended claims the term wall is intended to include a ceiling.

While I have shown my invention in but two forms,

it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various other changes and modifications without departing from the spirit thereof, and I desire, therefore that only such limitations shall be placed'thereupon as are specifically set forth in the appended claims.

What I claim is:

1. In fire resistant ceiling construction, a lower layer of acoustical tile formed of fire resistant material, means supporting the tile along the edges thereof, a layer of mineral Wool in the form of unwoven random arranged fibers substantially covering the upper surface of the tile andplaced with its lower surface lying directly on the tile, said layer of mineral wool being from two to four inchcs thick and having a density of between two and five-tenths to seven pounds per cubic foot, and an imperforate sheet of aluminum foil co-extensive in area with the area of the mineral wool layer located intermediate theupper and lower surfaces of said layer of mineral wool and lying substantially parallel to the upper surface of the layer of tile.

2. in tire resistant ceiling construction, a lower layer of acoustical tile formed of fire resistant material, means supporting the tile in spaced relation to a superjacent part of the building, a layer comprising mineral wool bats of unwoven random arranged fibers, said bats lying side by side in contact with each other directly on the upper surface of the tile layer and substantially covering the upper surface of the tile layer, saidbats being from two to four inches thick and having a density of from two and five-tenths to seven pounds per cubic foot, and an imperforate sheet of aluminum foil on the order of nine-ten thousandths inch thick in each'bat between the upper and lower surfaces thereof and lying substantially parallel to v the upper surface of said tile layer, said sheets of foil 5 being substantially co-extensive in area with the area of the bats.

References Cited in the file of this patent UNITED STATES PATENTS 5 449,152 Enricht Mar. 31, 1891 1,914,345 Roos June 13, 1933 1,926,679 Kellogg et a1. Sept. 12, 1933 1,994,439 S1ide1 Mar. 12, 1935 w 6 Stranahan Oct. 13, 1936 Ross et a1. Apr. 20, 1937 Johnson Sept. 5, 1939 Parkinson Oct. 24, 1939 Wasserman Nov. 19, 1940 Slayter Oct. 7, 1947 Tucker July 24, 1951 FOREIGN PATENTS Switzerland Jan. 16, 1940

Claims (1)

1. IN FIRE RESISTANT CEILING CONSTRUCTION, A LOWER LAYER OF ACOUSTICAL TILE FORMED OF FIRE RESISTANT MATERIAL, MEANS SUPPORTING THE TILE ALONG THE EDGES THEREOF, A LAYER OF MINERAL WOOL IN THE FORM OF UNWOVEN RANDOM ARRANGED FIBERS SUBSTANTIALLY COVERING THE UPPER SURFACE OF THE TILE AND PLACED WITH ITS LOWER SURFACE LYING DIRECTLY ON THE TILE, SAID LAYER OF MINERAL WOOL BEING FROM TWO TO FOUR INCHES THICK AND HAVING A DENSITY OF BETWEEN TWO AND

Images