US2099093A - Roof composition and method of producing the same - Google Patents

Description

Nov. 16, 1937. H. c. AVERY ROOF COMPOSITION AND METHOD OF PRODUCING THE SAME Original Filed March 28, ,1932

Patented Nov. 16, 1937 PATENT OFFICE ROOF COMPOSITION AND METHOD 0F PRODUCING 'THE SAltiE Henry C. Avery, New Brunswick, N. J., assigner,

by mesne assignments, to The Patent and Licensing Corporation, New York, N. Y., a corporation of Massachusetts Application March 28, 1932, Serial No. 601,702

Renewed June 25, 1935 4 Claims.

This application is a continuation in part of my application Serial No. 256,862, led February 25, 1928. I

This invention relates to composition roofing 5 and has more particular reference to animproved asphaltic roofing material and a method of producing the same. My invention finds one particular adaptation in that type of roong which consists of a felted foundation of brous material, such as rag or asbestos or similar libres formed into a sheet on a paper making machine, and converted into material suitable for use as roofing by saturating the felted sheet with a Waterproof saturant such as molten asphalt, and then coating on one or both faces thereof, With waterproof and weatherproof material such as blown asphalt. This coating material is usually spread upon the sheet in a layer of suicient thickness to provide a barrier to the entrance 20 of moisture into the pore spaces of the sheet, and

to otherwise protect the sheet against the iniluence of the elements. As already indicated, one of the important functions of the layer of coating material, is to prevent the absorption of 'moisture by the sheet, since the absorption of moisture renders the material liable to deterioration upon exposure to the changing weather conditions, by virtue of the fact that the absorbed moisture tends to swell or bulk the felted base and cause disintegration thereof under the changing weather conditions. It is important that the layer of coating material should pre' serve its exibility and ductility as long as possible and retain its integrity so as to properly protect the sheet against the entrance of moisture thereinto, and otherwise enable the coating layer to perform its protective functions.

The coating layer applied to the face of the sheet which will normally constitute the exposed 40 surface of the roong material may have imbedded therein a layer of grit or crushed mineral or any suitable form such as .crushed slate or the like, the purpose of which is to provide a masking layer of .wear and weather resistant material for the waterproof coating, and to impart to the roofing material any desired ornamental color eifects. From a sheet thus prepared, there may be then' cut the roong shingles or shingle strips in the form in which they .are 50 to be applied on the roof or the sheet Amay be formed into rolls and applied as roll roofing.

'I have heretofore referred to the necessity for covering the felted base of this type of roofing with a layer of coating material of sucient thickness vso as tc aiord at all times adequate protection for the felted base. I have observed that in the prepared roofing as produced under pres'- ent day commercial operation, the coating layer is in time affected by the action of atmospheric conditions normally` existing inv actual use to such an extent that ultimately it ceases to provide the necessary protection to the roofing base. While the material which is usuallyemployed as the coating for the roofing bas is generally a blown asphalt having a melting point of about 220 degrees F., I have found that nevertheless the atmospheric conditions to which the roong material is sometimes subjected, are suflicient to induce what appears to be a very slow and irregular internal flow of the coating material, the nature and extent of which varies with the Varying weathering conditions to which the material may be subjected. Apparently under the influence of the solar rays and sometimes also under the action of the excessive temperatures of the roof-supporting structure, there is caused more or less internal ow of the coating material in various directions and in irregular degree, due apparently to the polymerization and surface hardening and shrinkage of the exposed coating layer induced by the normal weathering effects. The slipping of the polymerized and hardened surface layer over the softer and yet unaffected portion of the coating layer, Vcauses the former to crack and the softer portions to ow into the cracks thus produced. It will be appreciated, of course, that this flow and the displacement of the harder material by the Lsofter, is indeed imperceptibly slow and can be observed only upon examination of the coating layer over considerable periods of time. It is a fact, nevertheless, that this flow does occur and proceeds continually, with the formation, as a result. thereof, of numerous ridges or crests and furrows or valleys distributed in irregular fashion over the surface of the roofing base, and orfdinarily giving a crazed or checked appearance thereto. These formations, which I believe to be due to the aforesaid occurrence of internal ow, may be readily noted upon examination of roong material of this character which has been v exposed Yon a roof for a considerable length of time, during which'it has had an opportunity of being subjected to one or more normal cycles of changing weather conditions. Manifestly these formations Y'detract from the protective properties of the coating layer, since the continuance of this action ultimately results in hardening of the coating to such an extent that the material becomes brittle, and the cracks formed as above described, or by the movement of the roofing base under the action of wind and local expansion and contraction, give access of moisture to the roofing base and otherwise expose the base to rapid deterioration.

These diiiiculties cannot usually be avoided by employing a layer of greater thickness or of a thickness in excess of the usual optimum thickness which ranges from .025 'to .060 of an inch, since a layer of asphalt which is too thick is liable to crack from stresses set upby unequal heat and cooling, especially in winter weather when the coating asphalt becomes unusually hard and brittle.

By my present invention I provide a method whereby the foregoing diculties may be elimiv nated. In accordance therewith, I combine with the ordinary layer of coating material applied to' the sheet in the manufacture thereof, an additional layer of material which is itself highly water resistant and also capable of resisting to the utmost any tendency for internal now to take place therein and which furthermore prevents the internal flow,v from taking place in the layer of asphalt thereunder. In this Way the combined layer permanently retains the desirable uniform thickness and avoids the production of checking and crazing on the exposed surface thereof, such as occurs in the roofing products of this type as now produced.

In carrying out my invention I employ in conjunction with the ordinary layer of coating asphalt a relatively thin overlying. layer or film of a dispersion o f waterproofing material. In order to effectuate the purposes of my present invention, the dispersion layer must be of a non-drying base such as asphalt, and the dispersed base should preferably be softer than the underlying coating layer. The dispersion is one which upon the removal of the water and the coalescence of the dispersed particles vassumes a structure rendering it capable of resisting ow at temperatures greatly in excess of the fusing or melting point of the dispersed asphalt. Dispersions of asphalt having the aforesaid property of drying to a relatively infusible film, may be produced in various ways, although I prefer to employ for this purpose a-dispersion of asphalt of a melting point ranging from to 170 degrees F., made as described in the patent to Lester Kirschbraun No. 1,620,900. Asphalt dispersions made in accordance with the Kirschbraun process are capable of drying to a film of substantial smoothness, the'weathering of the film proceeding uniformly and without any checking or crazing of the film. By providing a lm of suicient thickness, the weathering action is only superficial and does not affect the entire depth of the film. When a dispersion of this character is superposed upon a layer of asphalt and lthe water is driven oi or otherwise removed therefrom, it forms with the subjacent layer of asphalt an inseparable structure. In this structure, the outer layer of coalesced asphalt provides the requisite waterproofing and weatherproong qualities and by virtue of the peculiar physical structure of this composition it is itself completely stable to internal flow and furthermore prevents the occurrence of internal ow in the subjacent layer, or in any case prevents such v internal flow from affecting the uniform thickness of the composite layer and evidencing itself in the form of cracks and cheeks on the outermost surface thereof. Furthermore, because of the flexibility and ductility of the softer asphalt used in producing the dispersion lms of this type and movement, they remain substantially unaiected4 by extreme conditions of temperature, and noy cracking of the outer surface of the composite layer results under such conditions, and the resistance to the destructive action of the weather is thereby greatly prolonged. In order to increase the opacity of the dispersion film, as well as for other desired eects, suitable fibrous or granular fillers may be combined with the dispersion.

The principle of my invention as heretofore described may be utilized with advantage in the production of roofing having other than a felted fibrous base, and protected with an asphaltic layer. Thus in accordance herewith, the composite layer of asphalt surmounted by a layer of asphalt dispersion may be applied to metallic, and wooden roofing bases, as well as to bases composed of various moulded compositions such as cement and the like, or even to bases composed of moulded compositions of asphalt and fiber or other ller.

In the accompanying drawing, the several views are enlarged cross-sections of roofing material which-may be produced in accordance with my invention.

In these views, numeral I indicates the roong base which may be a felted sheet, or any other desirable base, such as metal, wood, or a moulded composition. At 2 is indicated the layer of coating which may be applied in any convenient manner to the base after the formation thereof. The numeral 3 is intended to indicate the layer of coalesced asphalt.

In Figure 1, the layer of coalesced asphalt 3 provides the finish coat for the roofing and this construction is particularly suitable for the production of a felt base product similar to the rubber roofing of commerce, and having no surfacing material in the outermost layer.

In Figure 2, the layer 3 may have imbedded therein a surfacing material 4 such as crushed slate or the like.

In the form shown in Figure 3, the asphalt layer may have ne grit 5, such as talc or mica imbedded therein, and the layer 3 of asphalt dispersion is superposed upon the layer of fine grit so as to completely fill the interstices therebetween and form a coalesced 'asphalt layer of desired thickness firmly united to the subjacent layers. If desired, talc or similar surfacing material may be applied over the layer 3 of coalesced asphalt in the construction illustrated in Figure 3.

In producing roong material having a felted fibrous foundation in accordance with my invention, the usual manner of saturating the felt base sheet may be followed and after the sheet has been withdrawn from the saturating apparatus and the saturant on the surfaces of the sheet has been absorbed into the pores thereof, the sheet is then conducted to the usual coating rolls where coating asphalt, as for example a 220 degreeF. melting point blown asphalt is applied thereto. The thickness of this coating layer may be substantially the same as is common in the industry, but by suitably adjusting the coating rolls the thickness of the coating may be varied as desired, so as to produce a thinner layer than the usual coating layer of. asphalt. Before this layer of molten asphalt has cooled, there is then applied thereover the dispersed asphalt so as to produce a layer of asphalt dispersion of uniform thickness overlying the relaw water from the dispersion layer to enable the tively hot soft layer of asphalt. In order that the weathering of the resultant film shall be supercial only and not affect its entire depth, the dispersion layer should be regulated in thickness from 0.020 to 0.030 of an inch. The asphalt dispersion may be applied in any convenient way as by means of a sprayor the like. As the sheet progresses in its travel, the heat from the coated base will ass/ist in the-evaporation of the water from the layer of asphalt dispersion. Where it is desired to apply mineral surfacing the sheet may be fed along until theV dispersion layer assumes a substantial degree ofvtackiness, so that the surfacing material may be applied and pressed by suitable rolls into intimate contact with the tacky layer of the asphalt dispersion. As the water becomes completely removed from the dispersion layer, the particles thereof coalesce and at the same time the underlying layer of asphalt cools suiiciently to cause it to harden, the layer of coalesced asphalt thus becoming united into an inseparable structure with -the hardened layer of asphalt.

- In some cases the opposite surface of the sheet may also be provided with. a coating layer of asphalt and in such case, this layer may also have applied thereto an overlying layer of asphalt dispersion similar tothe layer 3.

VThe foregoing method may, if desired, be modied by delaying the application/of the asphalt dispersion to the coated sheetuntil the layer of the coating asphalt has `cooled andv solidied. This may be readily accomplished without entailing the loss of a great deal of time, inasmuch as the coating material generally employed has a substantially high melting point, so that by conducting the sheet with the layer of asphalt thereon through the atmosphere for a relatively short distance, this layer will very quickly congeal and harden. If desired, the cooling of the asphalt layer and the solidiiication thereof may be assisted. by directing a blast of cool air upon the coated sheet, prior to the application of the asphalt dispersion, 'and similar means may also be employed if desired to assist the removal of latter to more quickly dry and harden or reach an adhesive and tacky condition suitable for the Vapplication of the surfacing material thereto,

i ing structure, it is desirable sometimes, for purposes of economy, to omit the granular surfacing -material and to finish the roofing with a coating of colored material to impart to the roof at least some degree of ornamentation. In producing roofing material of this class, in accordance with my invention I employ for thedispersion layer to be applied over the ordinary asphalt coating, a

dispersion of colorable waterproof pitch, or the like which as before stated is of a non-drying base, softer than the underlying coating and approximately of the same characteristics as the dispersion lms applied jas previously described. The dispersion of this material may be formed in accordance with the processes described in the said patent to Lester Kirschbraun, and the dispersedv material may then have incorporated therein any desired coloring agent such as mineral pigment, or the like. The colored dispersionV may then be applied to the sheet previously coated with asphalt, in accordance with any of the methods above described.

My invention is also adapted for building up a structure in place upon a' roof. For example, asphalt coated roofing in the form of rolls may be applied to the roof "structure, the successive layers being cemented along the overlapping 'margins thereof in the well known manner, and thereafter the sheets may be covered with a layer of the dispersion, the latter being either sprayed or brushed onto the surface and then permitted to dry and harden, and form the composite layer with the coating material of the roong base as already described. Obviously, mineral or similar surfacing material may, if desired, be distributed in any suitable way in the outermost layer of dispersion, before the latter has completely hardened.

It will be noted that in all the forms in which my invention lmao' be embodied, I provide a composite coating layer, the outermost portions of which comprises an infusible structure which serves to prevent rapid deterioration of the fresh and intact subjacent stratum or asphalt or similar coating substance.

It.will be apparent that while I have described my invention in connection with roofing, I do not mean to be restricted thereto, as obviously, many other surfaces which are subjected in use to weathering conditions and similar destructive action may be protected and their resistance to such asphalt before the same has congealed. Thereafter, when the under layer of molten asphalt has set and the film of emulsion has coalesced, the grit will be anchored both by the asphalt layer and the coalesced emulsion layer, thus oii'ering a secure anchorage for the grit.

What I claim is:

1. The method of making roofing of the character described which comprises coating a rooing base with molten bituminous waterproofing material having a relatively high melting point, ap-

plying to the coated sheet a secondary coating of bituminous waterproofing material of relatively low melting point dispersed in an aqueous medium, while the rst named coating is at an elevated temperature whereby to eiect a heat interchange between said coatings, and permitting the secondary coating to dry and become united with the first named coating.

2. The method of making roong material of the character described which comprises coating a saturated sheet of roofing base with molten `waterproofing substance, and substantially imafter applying to the coated sheet a secondary coating of asphalt dispersed in an aqueous medium, applying grit to and embedding the same in both coatings and permitting the secondary coating to dry and become united with the rst 5 named coating.

HENRY C. AVERY.

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