US1767374A - Method of making roofing elements - Google Patents

Description

June 24, 1930. KIRSCHBRAUN METHOD OF MAKING ROOFING ELEMENTS 2 Sheets-Sheet 1 Original Filed Aug. 24, 1925 KIRSCHBRAUN METHOD OF MAKING ROOFING ELEMENTS June 24, 1930.

Original Fil'ed Aug. 24, 1925 2 Sheet-Shet 2 Patented June 24, 19 30 UNITED STATES CORPORATION O1 MASSACHUSETTS PATENT oarce i LESTER KIBSCHBBAUN, OI LEON IA, NEW JERSEY, ASSIGNOR, BY MESNE ASSIGNMENTS,

. TO THE PATENT AND LICENSING CORPORATION,

OF BOSTON, MASSACHUSETTS, A

METHOD MAKING ROOFING ELEMENTS Gontinuation of application Serial 110. 134,412, filed September 9, 1926, which is a division of application- Serial No. 61,949, filed August 24, 1925. Patent No. 1,612,776, dated December 28,, 1928. This application iiled October 8, 1929. Serial No. 898,232.

This invention relates to the production df roofin elements generally of the character of s ingles, slabs, shingle strips, clapboard or the like, in which, when the material is laid upon the roof in overlapping courses, there are exposed marginal portions with edges that are subject to deterioration caused by the sunlight and the elements, the subject matter of this application being a 10 continuation of my copending application Serial No. 134,412, filed September 9, 1926, which in turn is a division of m copending application Serial No. 51,949, led August 24, 1925, upon which Letters Patent No. 1,612,776 were granted to me Dec. 28, 1926. Ordinarily, in the manufacture of modern roofing such as employed for these purposes, it is the custom first to form a sheet of felt which is made ordinarily of ra fibers or rag and asbestos fibers or the like, of the desired caliper and of sufiicient porosity to permit it to absorb a molten waterproofing composition such as pitch, asphalt or the like, and of sufficient strength to enable it to be manipulated during the operations of forming the ultimate roofing product. This is a common article of commerce which is ordinarily known as roofing felt and is produced on the usual paper-making machines. Afterthe sheet has been properly saturated with the bituminous saturating compound, either by immersion in a bath of a molten bitumen or pitch, or b subjection to pressure saturation, the s act is coated on one face with a fairly thin layer of high melt ing-point asphalt. For this purpose, oxidized or .blownasphalt smcalled. 1s preferably employed because of its tough and rubbery nature. While the asphaltic coating is still soft and plastic and before it has set, it is surfaced with any suitable form of crushed mineral such as crushed slate, tile or any other mineral grit which will im art the desired color and texture to the final product. The grit is preferably formed in relatively large particles or granules which vary in form according to the material from which they are produced. The surface min- 'eral coatin is partially embedded in the plastic asp altic'coating sufliciently to in sure a firm interlockin of the granules with designs or in long narrow strips which may be employed for the sides of buildings in the same manner as'wooden clapboards.

The operation of the cutting machinery is such that, when these roofing elements are produced, at all of the ed es of the element there are exposed first t e saturated felt, next a thin stratum of asphalt, and finally the layer of grit the grains of which are partially embedded in the asphalt.

It has been discovered that asphalt exposed to the elements and to the sunlight is susceptible to rapid deterioration; It is known, for example, that the action of sunlight or of the ultra violet rays is such as to cause a condensation of polymerization of the asphalt, resulting in the hardening of the asphalt with a consequent checking or brealn'ng down of the asphalt particularly when it is exposed in relatively thin fihns or layers. This is especially true of the asphalt or other bitumen which is utilized as the saturating compound for the foundation felt, inasmuch as the films of asphaltabout the fibers of the felt are relatively thin. Due to the action of the light and of moisture, these films crumble; and this, together with the absorption of moisture by the exposed fibers, causes the breaking down of the exposed edges and produces a tendency on the part of the exposed margin of the roofing element to curl. The curling is doubtless also accelerated by the fact that the layer of coatin asphalt contracts under the influence 0% the elements and the rays of the sun and because of oxidation to a greater extent than the saturated felt itself.

On the other hand, a single layer of asphalt which is too thick is liable to crack through from internal stresses set up .by unequal heating and cooling, especially in winter weather when the asphalt is comparatively hard and brittle.

Cracks thus formed in a coating of asphalt admit moisture to the fibrous foundation of the element which is absorbedand tends to bulk or swell the felt. This, especially in conjunction with frost, tends to disintegrate the element by warping it, loosenin the asphalt coating and extending the original crack or fissure. To secure best results in weather roofing with a sin le coating of blown asphalt, such coating should be from .040 to .070 of an inch thick. The grit surfacing material usually applied to such a coating often comprises particles large enough to extend all the way through the coating and puncture it. If these particles are dislodged in the subsequent treatment and handling of the roofing, they leave small pin-holes in the coatin through which moisture can enter. While'these breaks in the continuity of the surface coat are not as serious 9. cause of deterioration of the element as are the cut exposed edges, yet their tendency is in the same direction,

namely, to shorten the life of the element.

An extra coating of asphalt over the surface of the element which is exposed when laid closes all such pin-holes and other possible breaks in the first coating. Although the second coating infiltrates between the particles of grit and bonds with the first coating, the grit layer maintains the separate identity of the two coatings and prevents the cracking stresses which would ordinarily be set up by thermal changes in a single layer of coating material of a thickness equal to the sum of the two coatings.

In the practical production of the roofing elements herein referred to, it is customary to apply the grit surface layer to only one face of the product, a portion of which is to be exposed to the weather, and in most cases the under face of the roofing elements consists of merely the saturated felt. In some instances it is true that a thin layer of the asphaltic coating is applied to the under face of the roofing element when the sheet is being saturated and coated. When the elements are laid in overlapping courses, however, water finds its Way under the exposed edges and margins of the elements, either by capillary action or by the beating rain with the assistance of the wind, and in winter weather this moisture freezes and thaws and has the effect of lifting the exposed edges of the roofing elements from contact with the elements overlapped thereby, so that the deterioration of the asphalt hereinbefore referred to is localized not only at the edges of the roofing element but also extends through the under face thereof with the consequent tendenc to disintegration and destruction of the oundation sheet. This is true even in cases where the under face of the product is coated, for the reason that ordinarily such coatings are so thin that they are rapidly attacked and their efiiciency destroyed.

The problem which thus presents itself is to find some way of preventing or overcoming the deterioration at the cut edges of the roofing material and of prolonging the effective life of such roofing elements. In attacking this problem, one is confronted with the fact that the saturated felt is the weakest component of the roofing product so far as its liability to deterioration is concerned. The cellulosic fibers of which it is formed have an affinity for moisture, and the saturated felt itself ordinarily will absorb moisture up to 20% of its weight. Yet the integrity and the strength of the roofing product are directly dependent upon the integrity and strength of the saturated felt, for if this be destroyed the product as a whole loses its waterproofing and durable characteristics. The deterioration of the saturated felt is evidenced by progressive loss of cohesiveness and structural strength, so that the resistance of the final product to the weaving of the roof structure and its flexing through the action of the winds and the elements becomes insufiicient to maintain it in place.

In seeking an answer to the problem, therefore, means must be provided for the maximum protection of the saturated felt to prevent access of moisture, oxygen and light thereto. This is accomplished by providing what may be termed a supplemental coating of high melting-point asphalt, preferably blown asphalt, in a layer of sufiicient thickness so as completely to seal the fibers of the felt with an impermeable envelope so as to prevent the access of air or moisture; but, inasmuch as asphalt itself is subject to deterioration through the action of light as hereinbefore stated, the impermeable asphaltic envelope itself is liable to deterioration and destruction. Consequently to overcome this deflect, means mustbe afforded for preventing the access of light to the asphaltic layer. closing the asphaltic layer within an opaque layer. Any suitable opaque material may be utilized for this purpose, but as a practical matter one may employ crushed slate, crushed tile, or any other opaque granular material which may be partially embedded in the asphaltic layer in such manner as completely to cover it and to prevent the access of the rays of the sun directly thereto to any substantial extent.

The present invention comprises an individual roofing element in the nature of a shingle, shingle slab or strip, having the exposed edges sealed by an enclosing envelope of asphalt -or bitumen and the envelope itself is protected against light by a surface This is accomplished by enmama's layer of an opaque material preferably a plied in granular form;

Incidentally, however, I'have found that f it is possible to produce a roofing material which issuperior to those heretofore made of flat sheets, in that the element may be so.

formed that it is gradually thickened to wards what may be called the butt or exposed end thereof. Thus, when the roofing ment as heretofore produced. First, by reason of the fact that theelement is thickest at the butt or exposed edge thereof, its weight is greatest at the edge and consequently theex'posed edgeofiers greater resistan'ce tothe lifting force of the wind and will remain flat when the flat elements of unvarying thickness would be lifted or raisedby the winds'pressure- This also permits of grtater area of exposure. Again, inasmuch as both faces (that is,'the upper and the lower faces) of the element are coated to substantially the same extent by the asphaltic envelope, there is no tendency for the exosed ortion of the element to curl away rom't e elementoverlapped thereby. Asphalt, when exposed to light and the elements, tends to contract; 'fllld, where the roo element has no or only a thin layer of .asp alt on its under side and a relatively thick layer on its exposed side, the cpntraction of the exposed'layer causes the curling of the entire element. This is observableonmany roofs which have been covered with flat individual slate-surfaced shingles.

In the production of such elements 'as herein described, one may start with the ordinary roofing elements of commerce, name- 1 individual shingles, strip shingles or slabs, or cla board slabs, all of which are designed to laid in overlapping courses with what may be termed for convenience exposed butt portions. 7 These butt portions are dipped into a bath of molten asphalt for.

a'suflicient time to cause them to be covered on bothffaces and on their-exposed edges with a fairly thick layer of asphalt. On removing the elements from the asphaltic bath, they are permittedto hang vertically and drain sufliciently to permit the excess asphalt to drop therefrom and to permit a flow of the attached coating so that it is thickest at the pendent edge of the element. While the coating is still soft and plastic, it is coated on both faces and on its edges with a layer of opaque granular material,

.tions and intervening notches e, 0.

the grains of which are artially embedded in the asphaltic coating ut protrude thererom so as to completely cover and mask the asphaltic envelope.

On the accompanyin drawing I have ilinvention may equally well be incorporated or embodied in an individual'shingle, or a cla' boardstrip.

igure 1 represents a shingle strip as ordinarily formed, and which inithe present instance serves as the starting material of my roduct.

not.

,Figure 2 represents the completed pro'd- Figure 3 represents a section on the line 3-3 of. Figure 2.

Fi re 4 represents an enlarged section on the lnie 1-4 of a part of the stri shin le.

of a double-dipped shingle.

Figure 7 represents in perspective a tank A in which shingles may be dipped.

- Figure 8 represents a receptacle for grit orother comminuted material by which the dipped shingle is surfaced.

Referring to the drawing, I have shown in Figure 1, at a what is commercially known as a slate surfacedsquare butt strip shingle, which is provided at b, b with tabs or ro ecshin le is usually laid with others in overlapplng courses, so that the butts of the tabs register with the upper ends of the notches of the strips overlaid thereby. The tabs may, for example, be four inches in length, where the entire strip is ten inches between its upper and lowen edges. Of course it will be understood that the design of the strip shinglev may be varied, so that the tabs may be semi-hexagonal, or semioctagonal, or of any other desired shape.-

The shingle strip, as shown, has abase of rag or asbestos felt 10, which is impregnated with asphalt or other commonly used waterproofing compound, a layer 11 of higher melting-point asphalt, and a surface layer 12 of granular material.

The strip is held by its straight upper edge, and is dipped into a bath of molten asphalt, which is preferably oxidized or blown asphalt having a melting point of 220240 F. The dipping operation must. be carried on while the molten asphalt is at an elevated temperature, and is so timed that the strip will pick up the proper amount ucha of asphalt and also readily freeitself of the lustrated a strip shingle embodying'the invention, but it willbe understood that the Figures 5 and 6 illustrate the ormation will be appreciated that the viscosity of an oxidized asphalt at a given temperature, will vary with the nature ,of the stock from which it is prepared, as well as its melting point, and the temperature to which it is heated. Therefore the temperature range which I have given is only indicative of the viscosity of the particular stock there referred to. The period in which a part of the shingle strip is dipped in the asphalt must be very short in order not to melt or unduly heat or soften the underlying bituminous material unnecessarily. One or two seconds is usually suliicient.

The shingle strip is dipped in the bath far enough to cause the molten asphalt to cover all of that portion of the strip which will be exposed when it is laid, usually to a longitudinal line parallel to the upper edge of the strip about half an inch to an inch above the ends of the notches. The strip is removed from the bath and while hanging is permitted to drain momentaril to permit the coating 13 on both faces to ow toward the lower edge, and thus form tapered layers which are thickest at the edge, the excess drops being flipped or else wiped'ofi'. The process thus far described may be carried out manually by the use of a suitable pool of molten asphalt 20 contained in a tank 21 which is of sufficient length to receive the strip shingle. The asphalt may be maintained at the desired temperature by any suitable heating means, such as steam coils 22, disposed near the bottom thereof. In order to wipe the dripping asphalt from the butt edge of the dipped shingle, wiping elements such as steam pipes 28, 24, may be provided at convenient locations as shown in Figure 7. The strip is now surfaced with an opaque grit 14 which is caused to become partially embedded in the still plastic asphaltic coating or envelope, not only on the faces of the strip but on all the edges thereof which are asphalt-coated, and-as a consequence there is a continuous layer of exposed grit which extends over both faces and across all of the lower edges of the strip, including the edges of the tabs and the edges at the upper ends of the cutouts or notches. This may be done by first pressing the strip flatwise against a thick layer of loose grit, 25, which may be conveniently located in a suitable box or container 26, then rocking the strip through an arc of 180 about its asphalt-coated lower edge as the center as indicated in Figure 8, and pressing the other face against the layer of loose grit, and forcing or piling grit into the cutouts or recesses and against the end edges of the strip. This molds the asphalt and grit at the'lower edge of the strip and furnishes a straight rounded edge which is pleasing in appearance. The strips are piled one on the other, as produced, and the weight of the pile forms flat terial, which is emplo ed to cover, protect and mask the asphaltic envelo e, I refer to employ grit or granules o a di erent color and/or size from those which originally formed the outer layer of the original strip, especiall in the case of strip shingles or, indivi ual shingles, so that a contrast will be afforded between the exposed portions thereof and the upper portions of the overlapped strips, which arev visible through the notches, or through the spaces between the individual shingles. instead of starting with a grit-coated roofing element, as hereinbefore described, one may start with a roofing element out from rubber roofing, so-called, which is an asphaltimpregnated sheet, having layers of high melting-point asphalt on one or both faces thereof. Usually, but not necessarily, such rubber-roofing has a surface layer of talc or mica.

I should not regard it as a departure from my invention if the protecting asphaltic envelope of the roofing elements were surfaced with pulverized material, or with talc or mica, or if the envelope itself were formed of a-colorable pitch such as stearin pitch, or mixtures of resins and tempering fluxes, with a suitable pigment incorporate therein to impart the desired color thereto.

In instances where it is desired to keep down the weight of the roofing element, the front face and the edges of the strip may be surfaced with crushed slate partially embedded in the asphaltic envelope, and the rear face surfaced with a fine powder such as talc or mica.

In certain cases where an extra thick butt is desired on the roofing element, I may subject the element to a series of dipping and grit-surfacing operations. In such case, in the first dipping the element may be immersed, say, one and one half to two inches, and after the grit-surfacing operation has been carried out, and the asphaltic coating has set, the element is in the second dipping immersed to an extent of five inches, after which it is surfaced, covered and protected with a layer of granules of opaque material.

In Figures 4, 5 and 6, I have shown a strip which has been subjected to the series of operations last described.

Again,

color as the granules which coat. the faces of the strip. Such fines are the powders or dusts which separate from the larger granules of slate or other .m'ineral grit.

- the period of immersion or dipping is very short so as not to melt such impregnating 20, compound and the initial asphaltic coating;

In each of the roofing elements herein de-- scribed, the continuous asphaltic coatin which covers the-upper and under faces an the bottom and side edges of the exposed or butt portion thereof, is securely interlocke with the usual granular facing, if there be one, on the upper face of the element, and

more or less coalesces with the asphaltic impregnating compound at the edges and on the under faces of said butt portion. While yet there is suflicient heat in thesecond or continuouscoating'to cause a sufliclent softening thereof and to cause the necessary coalescense and interlocking of the two. '25

5 I claim:

1. A method of maln'ng roofing elements,'

which comprises dipping the butt portion of a previously formed-element, having an asphaltic coating and a layer of partially embedded granular material on one face thereof, into a bath of molten asphalt, withdrawing the element and sus en 'n it in an upri ht position for a brie perio with its butt e ge down, and applying a granular material to the coating thus formed while it is soft and plastic. A

2. A method of making roofing elements,

which comprises applying a coating of molten asphalt to the utt ed e ofa preformed element, placing said l mttedge in contact with grit while the asphalt is still hot and sticky, and rocking the element on the butt edge as an axis while said edge is in. contact with said grit.

.in one face of said element in contact with grit while the asphalt is still hotand sticky,

- and rocking said element on the butt edge as an axis, said butt edge being in contact with grit during said rocking.

4. A method of making roofing elements, which comprises dipping the butt portion of a pre-formed element into a bath, of

molten asphalt, withdrawing the element and permitting the asphalt to flow toward the butt edge, applying a face of the element to a body of. loose grit, and rocking said element on said butt edge while the latter remains in contact with said body of grit.

5. A method of making roofing elements,

. which comprises enveloping the butt portion of a pre-formed element completely 3. A method of making roofing elements,

witha coating of molten asphalt applying one face of said element to. a body of grit,

and rocking said element on the butt edge d said base. to coat the. butt'edge thereof, in

suspending the base to position its upper edge above the plane of the butt edge thereof to cause the waterproofing composition to flow over the surface of the shingle and gradually increase in thickness towards its notched edge and in applying granular material tosaid waterproofing coating.

v 7. A methodof manufacturing prepared roofing, comprising notching one edge of a roofing base to forma series of shingle simulating tabs on saidbase, coating a face of the base and the butt and side edges of the tabs while maintainingthe butt edge of the base .at a lower plane than the opposite edge thereof, to cause the coating to drain downwardly to increase the thickness of the coatling retained'on the base towards the notched edge thereof and applying to the coated portion of the base granular matter to be retained thereon.

8. A method of manufacturing prepared roofing comprising notching one edge of the roofing base to form a series of shingle simulating tabs on said base, coating a face of the base and the'butt and side edges of the tabs while maintaining the butt edge of the base at a lower plane than the opposite edge thereof, increasing the thickness of -the coating retained on the base toward the notched edge thereof by suspending the base in a position wherein the coating flows by gravity toward the notched edge and applying to the coated portion of the base. granular matter to be retained thereon. i

'9. A process for manufacturing roofingportion of a face of the strip and the butt and side edges thereof, suspending the strip to cause the waterproofing coating applied thereto to gradually increase in thickness by gravity flow thereof toward the notched edge of the strip and applying granular material to the coated portion of the-shim gle strip. I I

10. A process for manufacturing roofing strips having a notched edgeto provide shingle simulating tabs comprising the steps of retaining one edge of the strip at aplane beyond the notched edge thereof While coating a portion of a face of the strip, suspend- I ing the strip to cause the waterproofing coating applied thereto to gradually increase in thickness by gravity flow toward the notched edge of the strip and shaping the coating accumulating on the lower edge of the strip to present a predetermined contour.

11. A process for making shingle strips having tab portions simulatin individual shingles, consisting in coating t e butt portions of said strips with" a water roofing composition to cover portions of t e faces and the edges thereof to be exposed, in thereafter causing said strips to hang in a position to permit the asphalt to flow by gravity and to accumulatein a layer increasing in thickness toward the butt edge of the strip, in smoothing the butt edge of the strip, and in thereafter applying ranular material to the coated portion of the strip.

12. A method of making roofing which consists in applying a waterproofing coating to an exposed surface of the base and in suspending said base in a position whereby the coating will flow toward the lower edge thereof and gradually increase in the thickness toward said lower edge and in applying comminuted material to the coated portion of the base.

13. A method of making roofing which consists in applying a waterproofing coating to the exposed surfaces of a base, in suspending said base in a position whereby the coating will flow toward the lower edge thereof and gradually increase in thickness toward said lower edge and in applying commingted material to the coated portion of the ase.

14. In a method of manufacturing roofing wherein a base is notched to form shingle simulating tabs and is thereafter coated with waterproofing material over its exposed faces and edges, the improvement consisting in suspending the notched edge in a lower plane than the opposite free edge thereof to cause'the coating to gradually increase in thickness toward the notched edge and in thereafter applying granular material to the coated surface.

15. A process, for making roofing strips comprising the steps of notching one edge of the base of material of uniform thickness 'to form a strip having shingle simulating tabs, coating a surface of the tabs and the butt and side edges thereof with Waterproofing bitumen to seal the exposed edges and face of the shingle against weather deterioration, varying the thickness of the coating toward the butt edge thereof to thereby form a thickened and tapered butt edge and thereafter applying comminuted material to the thus coated and tapered exposed surface and the sealed butt and side edges thereof.

16. The process of making thick butt shingles which comprises the steps of successively subjecting said shingle to the application of waterproofing bitumen with each successive a plication extending to a reater distance f i'om the butt edge thereof t an the preceding application, and maintaining one edge of said shingle at a plane lower than the other edge whereby the water roofing bitumen gravitates downwardly to orm a tapered butt shingle.

17. A method of making roofing which consists in applying a waterproofing coating to an expose surface of a base, suspending said base in a position whereby the coatin will flow toward the loweredge thereof an increase in thickness toward the lower edge, and in subsequently applying another waterproofing coating to the exposed surface of said base,

18. A method of making roofing which consists in successively applying a waterproofing coating to an exposed surface of a base, with each application of bitumen extending a different distance from the lower edge of the base than the precedin applications whereby the butt edge may be built up to a predetermined thickness, suspending said base following one of said applications of bitumen in a position whereby the coating will flow toward the lower edge thereof and gradually increase in thickness toward said lower edge, and in finally applying comminuted material to the coated portion of the base.

19. A process for making roofing strips from base material of uniform thickness comprising the steps of coating a surface of the base including butt and side edges thereof with waterproofing bitumen to seal the exposed edges and the face of the shingle against weather deterioration, varying the thickness of the coating toward the butt edge thereof to thereby form a thickened and tapered butt edge and in thereafter applying comminuted material to the thus coated and tapered ex osed surface and the sealed butt and side edges thereof.

Signed at East Rutherford in the county of Bergen and state of New Jersey, this twenty-third day of September, A. D. 1929.

' LESTER KIRSCHBRAUN.

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