US3336179A - Glass reinforced roof system - Google Patents

Description

Aug. 15, 1967 v F w CAMPBELL ET AL 3,336,179

' GLASS REINFORCED ROOF SYSTEM Filea Jan. :5, 1966 3 Sheets-Sheet l FRANK w. CAMPBELL DALE A. LEHR IN VEN TORS BY @IMJJ ATTORNEY Aug. 15, 1967 F. w. CAMPBELL ET AL GLASS REINFORCED ROOF SYSTEM 3 Sheets-Shet 2 Filed Jan. 3, 1966 COMPRESSED AIR ' F IG. 2

IINVENTORS FRANK w. CAMPBELL DALE A. LEHR BYWIS/MJMW ATTORNEY Aug. 15, 1967 w. CAMPBELL ET AL 3,336,179

GLASS REINFORCED ROOF SYSTEM Filed Jan 3, 19 66 5 Sheets-Sheet s FRANK W. CAMPBELL DALE A LEHR INVENTOR ATTORNEY United States Patent 3,336,179 GLASS REINFORCED ROOF SYSTEM Frank W. Campbell and Dale A. Lehr, Dallas, Tex., assignors to The Archilithic Co., Dallas, Tex., a corporation of Texas Filed Han. 3, 1966, Ser. No. 518,463 3 Claims. (Cl. 161-72) This application is a continuation-in-part of application Ser. No. 214,132 filed Aug. 1, 1962, now abandoned. This invention relates to the formation of roofing structures which are watertight, which are readily applied and which will withstand Weathering over substantial periods without cracking. In a more specific aspect, the invention relates to the formation of a fiber reinforced waterproof film to form a waterproof finish.

The formation of Watertight roof structure in general .represents a substantial item of the cost of a building. Experience has taught that re-roofing operations often are required at'a relatively early age in order to protect the building interior from damage. The use of rigid roof shells of concrete and the like is widely known. However, in both new structures as well as re-roofing operations there still remains the problem of a reliable installation which will withstand the stresses developed by various weathering conditions.

In addition to reliability, it is often desired to incorporate various color effects to promote the aesthetic appearance of the roof which in prior art systems is difficult to achieve. A number of compositions have been developed which have highly desirable characteristics for the formation of films for a final coating on roofs and decks. However, such coating materials are expensive and must be used in minimum quantity in order to be competitive and yet must be used in suflicient quantity to assure a reliable installation.

It is an object of the present invention to provide a method and system for the application of such improved coating materials while embodying within the resultant coating a new measure of integrity. More particularly, there is provided a roof coating suitable for either a new roof or for a re-roofing environment which is competitive cost-wise with more conventional roofing systems but which incorporates therein a reinforcing medium which facilitates application of the coating to compounds, assures long life under severe conditions, and prevents shrinkage While permitting application of coatings of greater thickness. Also provided is increased tensile .strength with greater resistance to traflic wear. Further, there is incorporated a desirable appearance along with ability to withstand impact loads and coating forces by 7.

reason of continuity and mechanical integrity not here tofore available. 1

In accordance with the invention, there is provided a method of forming a stable waterproof roof at a site occupied by a new or an aged built-up pebble covered .roof. The roof is first stabilized by application of a first coating of a time curing cement, such as a lightweight aggregate layer, or a polyester cement. Thereafter, a thin coating of a resilient material is followed by a randomly dispersed uniform layer of glass fibers and at least one final coating of resilient material accompanied by a depressant force to integrate the fibers into the film.

For a more complete understanding of the present invention and for further objects and advantages thereof, reference may now .be had to the following description taken in conjunction with the accompanying drawings in .which:--.... e I a FIGURE 1 isan isometric view of a new roof installaltioni- I FIGURE 2is a sectional view of a pressurized chamber fordi'spensingfibrous materials;

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FIGURE 3 is a reduced sectional line 3-3 of FIGURE 2;

FIGURE 4 illustrates a modification of a guide and a compressed air entry port;

ljIGURE 5 is a sectional View of a fiber control gun; an

FIGURE 6 is an isometric view of a re-roofing installation.

Referring to FIGURE 1, a new roof is provided with a surface covering of a reinforced, flexible, waterproof skin. More particularly, in this example there is provided a roof deck 10 of preformed metal sheets supported by trusses 11. A relatively thin slab 12 of concrete is poured over the deck 10. The concrete slab 12 may be either an insulating concrete such as formed from expanded aggregates or may be conventional concretes of heavier density. In either case, the upper surface is finished as to provide a substantially continuous planar surface. The surface does not require trowel finishing but should be at least the quality of a float finished surface.

After the finished surface is dry and has developed its initial strength, a coat of a suitable coating material is applied.

The coating material may be one of several different types available. One type is of the class generally known as asphaltic or coal tar pitch, water type emulsions. Another type is of the class generally known as elastomeric materials such as polymerized rubber and the like. Representative of the first class is the coating material of the type manufactured and sold by the Koppers Co., of Pittsburgh, Pa., under the trade name Tar Guard. Tar Guard is a water-coal tar emulsion. Illustrative of the materials of the second type are those manufactured and sold by the Du Pont Company of Wilmington, Del. under thetrade' name Neoprene. In either case, the coating composition is first applied to the surface by spraying or by rolling. In FIGURE 1 a roller 14 is illustrated as being employed for applying such a coating compound. The roller is preferred in some cases because of the economy with which a continuous and reliable coating can be applied.

In cases where the finish is applied to corrugated roofing sections, spray application may be found profitable. After the entire upper surface of the concrete slab 12 has been coated with a first layer of the coating material, there follows a highly dispersed, relatively scant layer of continuous fiber glass rovings.

. In FIGURE 1 a tank 15 is provided in which a spool of fiber glass rovings is placed. A compressed air line 16 leads to the tank 15. An output line 17 connects an output port in the tank 15 to a fiber control gun 16. The air flowing through the tank 15 carries the fiber roving with it view taken along the through the gun 16. The gun is provided with a suitable dispersion type nozzle so that the fiber glass filaments issuing from the gun will be widely dispersed over the slab 12. Thereafter, a second layer of the coating materials is applied by the roller 14 over the fiber glass to incorporate the glass into a resultant thin elastomeric coating.

In practice, the fiber glass is applied with a density of about one to one and one-fourth pounds per hundred square feet.

The amount of glass installed will vary greatly dependent upon the desired or specified quality of the resultant film, while the coatings may vary in total thickness dependent upon various conditions and specifications. In one application of the invention, a coating of an elastomeric material such as neoprene was applied in the base and finish coats in such quantity as to establish a film thickness of the order of 0.020 inch. The coatings of from 0.020 to 0.100 inch or more may be built up by the present method. Since the coating material as applied contains solvents of high volatility, much of the total volume of the coating material as supplied in liquid form disappears during application and curing. In the example above given where a 0.020 inch coating was installed, neoprene was employed in the quantity of about four to seven or eight gallons per 100 square feet.

In order to apply the coating material on the fibers in such a manner as to be competitive even with the use of the coating compounds in quantities and of character that makes the cost thereof seem expensively high, it is necessary to apply fiber glass rovings to reinforce the coatings in relatively small quantities and at the same time to provide a substantially uniform dispersion of the fibers.

A preferred system for handling the glass fibers is illustrated in FIGURES 2-5. In FIGURE 2, for example, there is illustrated an improved and preferred embodiment of a pressure vessel which receives a spool of glass rovings particularly adapted to dispense the glass rovings. A relatively deep vessel 70 is provided with inwardly sloping shaped walls and a flat bottom. The diameter of the vessel 70 preferably is larger than the diameter of a spool of rovings so that a spool can be loaded or unloaded from the vessel with ease. The spool of rovings 71 is of the type in which the supply may be unwound from the inner wall 72 of the spool. The roving strand 73 will be understood generally to comprise a bundle of parallel, untwisted, separate strands of glass fibers or the like. Glass fiber rovings are commercially available in spools of bundles of twenty, thirty, one hundred or two hundred strands. The specific features of the control system for dispensing rovings of various numbers of strands will depend upon the bundle size to some degree as will hereinafter be pointed out.

The vessel 70 is provided with an upper shoulder 76 for sealing purposes. It is also provided with an outwardly extending segmented rib 77 which mates with locking means provided on a lid 78. More particularly, the lid 78 is provided with a segmented, inwardly extending rib 79. As best seen in FIGURE 3, the ribs 77 and 79 are intermeshed so that the lid can be placed over the vessel 70 and rotated to engage the ribs 77 and 79. A gasket 80 is carried in an annular recess 81 in the lid 78 so that, when the lid is locked onto the vessel 70, the gasket will bear on the upper shoulder 76.

The lid is provided with a blowout gasket or plug 85. The construction of the plug will be dependent upon the pressures to be employed in the given system. Also extending through the top of the lid 78 is a structure forming a flow channel. More particularly, a threaded bushing 86 and a supply line 87 are provided for introduction into the vessel 70 of compressed air or gas. The bushing 86 is threaded into the lid 78 and a fitting 88 is secured inside the lid onto the threaded extension of the bushing 86. The fitting 88 comprises an elbow in which the direction of flow of the compressed air is diverted as to be parallel to the inner surface of the lid and is thus prevented from impinging directly into the spool 70 and the roving strand 73 as it courses upward from the spool 71.

A roving guide 90 is provided in the upper region of the vessel 70. The guide 90 in the form shown is a V- shaped yoke which extends from anchor tabs 91 and 92 upward and toward the center of the vessel 70 to an apex which is located generally in the region of the axis of the vessel 70. The guide 90 is formed of a rigid smoothedsurface wire so that there will be minimized any entanglement or tendency to interrupt or interfere with the flow of the strand 73.

The strand 73 is threaded over the guide 90 and then extends through an outlet bushing 95 which is threaded into the wall of the vessel 70. A flexible hose 96 is secured to and extends from the bushing 95. The bushing 95 is provided with a central flow channel through which the strand 73 passes. The bushing is formed with a flared or rounded entry which is smooth so that there will be a minimum of wear or friction on the fibers as they enter therein. The fibers then course through the flexible hose 96 to a control gun such as shown in FIGURE 5.

Before proceeding with a description of FIGURE 5, it is emphasized that a fiber gun which will operate for extended periods is dependent upon the manner of control exercised upon the roving 73. In the course of producing spooled rovings, small segments or short lengths of fiber glass are left in the spool. Further, the movement of fiber rovings at relatively high velocities serves to establish electrostatic charges in the system so that there is a tendency to pull to the discharge port in the fitting debris and bits of glass fibers. Such debris tends to clog or disrupt the uniform flow of the fibers.

It has been found that control it materially enhanced by the inclusion of a suitable treating substance in or on the spool 71. More particularly, there is provided a lubricant for the fiber roving which in one form is a talcum powder. As indicated in FIGURE 2, the spool 71 is set on the bottom of the vessel 70. Talcum powder is then provided in quantity sufiicient to fill the center void and the annulus around the spool 71 to a suitable level generally indicated by the level 74. Some of the powder will be heaped onto the upper surface of the spool 71 so that the fiber as it is withdrawn from the spool will be coated with talcum which serves to lubricate the fiber in its course through the hose 96. Additionally, the talcum serves to assist in the removal of any electrostatic charge accumulated on the fiber roving as it is entrained for movement from vessel 70.

A spool of fiber rovings having the lubricant impregnated therein and distributed throughout the entire spool facilitates the handling of the rovings. Other lubricants than talcum powder have been employed with satisfactory results. Powdered asbestos, carbon, and aluminum have been used satisfactorily. Furthermore, by incorporating such materials into the spool of rovings itself, they can be dispensed in measured amounts proportional to the amount of roving drawn from the spool.

In FIGURE 5, the fiber control gun is illustrated as being coupled by way of the hose 96 leading from the vessel 70 of FIGURE 2. Hose 96 is connected to a bushing 100. The bushing 100 is part of a flow channel extending through the gun structure 101. A plug valve 102 is adapted to be rotated by a control handle 103. As indicated, the plug valve 102 is positioned in a cylindrical opening in the valve body 101 and permits fiber flow through channel 104 in the open position. A pipe extends from the forward end of the valve body 101. The flow channel 104 continues through the pipe 105 to a discharge point 106.

It will be noted that the channel through the valve body 102 is generally cylindrical and is tapered at the downstream section 102a. By this means, there is avoided the cutting of small segments of rovings when the valve is closed. Closure of the valve is brought about by moving the handle 103 in the direction of the arrow 103a. The edge 1021) of the valve body serves to sever the rovings as the valve is closed. However, since the diametrically opposite edge of the channel passing through the valve 102 is relieved as at section 102a, the trailing edge of the glass roving is permitted to continue on through the nozzle section 105 and is thus discharged, leaving the gun free and clear for re-establishing flow immediately upon opening of the valve.

It has been found necessary to make the valve substantially pressure-tight when closed. Otherwise, leakage of air therethrough causes the rovings to pile up in the flow channel 96 adjacent to the valve and thus causes the operation to become fouled upon attempted resump tion.

It will be noted that the fitting 100 is provided with smooth entry sections such as the faired entry port 100a. In addition, each connection element is similarly faired so that mechanical working of the glass fibers as they pass rate of discharge of the rovings produced by use of low pressure and a relatively small number of fiber strands per roving facilitates wide distribution and disintegration of the roving into separate filaments. As a result, there is a substantially uniform random distribution of fibers over the slab 12. In a preferred embodiment, the control gun of FIGURE 5 is provided with protrusions or deformations 105a along the fiow channel 105 at the discharge port, so that turbulence is created in the air stream as the fibers leave the gun, thereby greatly enhancing the distribution of the individual fibers.

The foregoing deals with the formation of a new roof illustrated in FIGURE 1 with the facilities described above in connection with FIGURES 2-5. It may be found desirable in forming the concrete slab 12 to add reinforcing glass fibers dispensed in the same manner above described and incorporated in the surface of the slab 12. Such reinforcement will inhibit the tendency to form hairline cracks therein. In any event, there is provided a relatively thin but reliable surface coating in which a resilient coating material is reinformed with a uniform dispersion of relatively low density of continuous fiber glass rovings. The continuous character of the rovings provides for a finer final appearance and greater continuity having greater tensile strength than is possible through the use of chopped fibers and the like and at the same time provides a medium which permits the use of the coating material which otherwise is difficult to control.

In FIGURE 6, the invention is illustrated in connection with an aged roof to be recovered for waterproofing or for appearance or both. The installation illustrated involves a lumber deck 110 supported by joists, such as joist 111, terminated adjacent. to a parapet wall 112. In the initial construction a cant strip was applied at the joint between the wall 112 and the deck 110 which, together with flashing 113, served to seal the roof. A built-up roof cover involving a plurality of layers of sheet material such as felt and hot asphalt with a final layer of gravel is represented by layer 114 In conventional re-roofing operations the gravel cover is removed along with one or more felt layers so that a virgin surface area is exposed. Onto this area a new built-up section topped with fresh gravel is applied. In accordance with the present invention, a new roof structure is applied without disturbing the old roof structure other than merely cleaning olf foreign debris such as leaves or papers, large rocks and the like which may have collected on the old roof. After the initial general cleaning, there is first applied to the old room directly on top of the gravel a stabilizing layer 115 of concrete in which fiber glass rovings are embedded. Ordinarily, a relatively thin layer 115 of light weight concerete may be applied to the order of three'eighths to one-half inch thick. However, it may be an inch or more, depending upon the dimensions of the pebbles used on the old roof and will be sufiicient to cover completely any such gravel or pebbles. Thinner layers of stabilizing materials may be applied when formed of glass embedded in sprayable polyesters, such as the sprayable polyester No. 4152 manufactured .and sold by American Cyanamid Co., of New York, N.Y.,

or the general purpose sprayable polyester manufactured and sold by Allied Chemical Co., of Morristown, NJ. Furthermore, a form 116 is provided at the juncture between the roof and the parapet wall which completely encases and old cant strip and flashing 113. The cement layer 115 thickens over the form 116 and continues up the wall itself and onto the'top of the wall. There is thus provided a continuous reinforced skin extending from the deck to the top of the parapet wall. In the example illustrated, the coating extends onto the top of the parapet wall. However, it may be terminated at the bottom of a parapet stone in a suitable reglet.

After the layer has been allowed to dry and to attain its initial strength, there is then applied an initial layer followed by a reinforced layer of sealing material in the manner above described in connection with FIGURE 1. In this case, however, the glass fibers together with the sealing material are applied as by roller 14 and gun 16 not only to the deck itself on top of the stabilizing concrete layer but also continue up the wall surface and onto the top of the wall. In a preferred aspect of the invention, the top layer of blocks, such as the blocks 120, is provided with a surface groove 121. As the coating material and glass fibers are applied, the coating is forced into the groove by a suitable finishing instrument so that the roofing coating is terminated at the groove 121 in a sealed manner. The groove will be filled with caulking to seal the coating.

In carrying out the roofing operations such as illustrated in FIGURES 1 and 6, the concrete mix forming the cementious material for the matrix in the stabilizing layer 115 may be of the following constituents and in the following relative proportions:

Table 1 Portland cement cubic feet 2 Polyvinyl alcohol of type such as Elvanol Grade 51- 05, available from Du Pont of Wilmington, Del.

pounds-.. Perlite concrete aggregate (8 pounds per cubic foot) cubic feet 2 2 There results a lightweight aggregate having a modulus of elasticity of the order of two to six million pounds per square inch. By reason of its relatively low modulus of elasticity and the inclusion therein of the alcohol, it is Wholly compatible with fiber glass strands.

Thepressurized container method and system for dispersing the fiber rovings disclosed herein are described and claimed in an application of James B. Winn, Jr., entitled Dispensing of Fibrous Material, Ser. No. 206,497, filed June 29, 1962, now Patent No. 3,111,270.

Having described the invention in connection with certain specific embodiments thereof, it is to be understood that further modifications may now suggest themselves to those skilled in the art and it is intended to cover such modifications as fall within the scope of the appended claims.

We claim:

1. The re-roofing cover for a built-up pebble-covered roof which comprises:

(a) a layer of light weight concrete having a depth approximately eyqual the major dimension of the largest of the pebbles on said roof for smoothing and stabilizing the surface of said roof,

(b) a thin coating on said layer of a waterproof coating emulsion,

(c) a cover over said roof overlaying said thin coating with a substantially uniform random dispersion of continuous glass fibers, and

(d) a second layer of said coating emulsion over said fibers to hold said fibers substantially at the configuration of the concrete layer.

2. The roof set forth in claim 1 in which said cover is an elastomeric material of a solvent type coating emulsion with glass fiber-s interspersed therein.

3. The roof set forth in claim 1 in which said cover therein.

References Cited UNITED STATES PATENTS 5 6/1917 Foster 52-58 10/1934 Dantz 52-516 11/1954 Castellani 161 8/1958 Donegan et a1 52-516 X 7/1963 Carr et al. 234-235 X 11/1963 Prentice 156-71 8/ 1964 Plumberg 161-156 8 OTHER REFERENCES Addex publication: How to Apply Addex Roofshield on Smooth Asphalt Surfaces, by Labco Inc., Cleveland, Ohio, 2 pp.

Asphalt and Allied Substances, by Abraham, 5th ed., pub. by D. Van Nostrand Co., New York, vol. pp. 736, 737, vol. 2, p. 1725.

Built-up Roofs, by Owens-Corning Fiberglas Corp., April 1952.

Journal of American Concrete Institute, February 1959, p. 5.

JOHN E. MURTAGH, Primary Examiner.

Claims (1)

1. THE RE-ROOFING COVER FOR A BUILD-UP PEBBLE-COVERED ROOF WHICH COMPRISES: (A) A LAYER OF LIGHT WEIGHT CONCRETE HAVING A DEPTH APPROXIMATELY EYQUAL THE MAJOR DIMENSION OF THE LARGEST OF THE PEBBLES ON SAID ROOF FOR SMOOTHING AND STABILIZING THE SURFACE OF SAID ROOF, (B) A THIN COATING ON SAID LAYER OF A WATERPROOF COATING EMULSION, (C) A COVER OVER SAID ROOF OVERLAYING SAID THIN COATING WITH A SUBSTANTIALLY UNIFORM RANDOM DISPERSION OF CONTINUOUS GLASS FIBERS, AND (D) A SECOND LAYER OF SAID COATING EMULSION OVER SAID FIBERS TO HOLD SAID FIBERS SUBSTANTIALLY AT THE CONFIGURATION OF THE CONCRETE LAYER.

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