US 2096784 A
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Description (OCR text may contain errors)
Oct. 26, 1937. I
w. w. CANDLER 2,096,784
ROOFING Filed July 12. 1934 45 (/6 INVENTOR. E. 41: Willi J4/JZZJC'E Carri/:27
Patented Oct. 26, 1937 UNITED STATES PATENT OFFICE 1 Claim.
This invention relates to roofing and more especially to roofing materials, such as paper, felt, -or the like, and to a method of preparing such roofing material so as to avoid trapping of air or gas between layers of the roofing sheets or between such sheets and the supporting surface thereforduring application of the sheets.
It is common practice in the roofing art to 1 use layers of a water-proofing paper, or felt, usually referred to as tarred or asphalt paper or felt, suitably bonded to each other and to a supporting surface by an adhesive or cementitious composition. Usually several layers of this material are employed one over the other in lapped fashion to constitute the roofing proper or to serve as a base for other roofing elements or coatings. The roofing paper or felt is usually composed of fibrous materials such as new or old rag fibers, wood or other vegetable fibers, asbestos, and the like, with the fibers bonded together with an impregnating material, such as tar, oil,-pitch, asphalt and the like, so that it is substantially impervious to air or gas as well as water.
In laying this type of roof, it is not at all uncommon for blisters or pockets to form between the layers of felt or paper, or between these and the supporting surface therefor. This difl'lculty has been so prevalent and serious that there is an increasing tendency for roofers to use some other and more expensive type of roof. This one dimculty has caused owners, roofers and manufacturers to be placed under enormous expense.
The principal object of this invention is to improve the art of roof construction.
A further object is to avoid. the formation of pockets or blisters in the construction of a roof covering.
Another object is to provide an improved roofing felt or paper.
Another object is to provide a roofing paper of felt which is permeable to air or other gases Without appreciably reducing the strength of this material.
A still further object is to provide an improved A Fig. 2 is a digrammatic view of apparatus use in fabricating the roofing paper or felt;
Fig. 3 is a plan of the prepared felt or paper; and
Fig. 4 is an enlarged section taken substantially 5 on the line 44 of Fig. 3.
In Fig. 1, a plurality of rolls III of roofing felt or paper II are shown in the process of constructing a roof covering. The rolls iii are arranged so that as they are paid out or unwound, 10 the sheets I l form a lapped or multi-ply covering with the plys secured together and to a supporting surface l2 by an adhesive or cementitious material I4, which may be in the form of hot tar, roofing pitch, asphalt, or cement, and the like. In laying the roofing felt or paper, the adhesive material I4 is applied to the supporting surface l2 and to the portion of the plys which are to be covered by other plys then the rolls I0 unwound and the sheets ll smoothed down'by means such as brooms, brushes, rollers, or the like. 1
To avoid the occurrence of pockets or blisters between the plys ll of the roofing material or between the plys and the supporting surface I2, the roofing felt is pierced as indicated at i5 in Figs. 1, 3 and 4, the felt being pierced at comparatively frequent intervals throughout its length and breadth to permit the passage of air or gas therethrough. Thus, as the rolls ill are unwound, any gas or air trapped below the sheets of roofing felt or paper is allowed to escape upwardly through the piercings l5 so that the felt may be readily and quickly smoothed against the supporting surface l2 and the plys of felt disposed therebelow. As the plys are smoothed down, the adhesive material l4 penetrates into the piercings l5 to close and seal the same, and at thesame time extends through the piercings so as to connect the adhesive material [4 on both sides thereof and therefore effects a more intimate bond between the various plys and results in a more rigid and homogeneous assembly of the water proofing materials.
It is preferred to pierce the felt plys H with a comparatively sharp needle-like means so as but slightly to separate or displace fibers thereof about the piercings l5 rather than to perforate the felt by cutting, punching or otherwise rupturing the fibers of the felt sheet. By piercing the sheet, the fibers are not broken or to any great extent torn apartso that the strength of the prepared sheet is not appreciably reduced. By piercing, as distinguished from perforating, by cutting, tear- ,ing or otherwise rupturing the felt, small openings only are left, which openings are readily closed and sealed by the adhesive material It so that each layer of felting, when applied, is rendered water-proof and closely adhered at all points to the suworting surface or felting disposed therebelow.
Reference may now be had to Figs. 2, 3 and 4 which depicts the preferred method of fabricating the roofing felt, and the product eil'ected thereby. According to Fig. 2, the felt II is prepared by passing the same through a tank 20 containing, as previously indicated, a bonding or impregnating composition 2|, such as tar, oil, asphalt, pitch, and the like, to impregnate the fibers thereof and render the felt water-proof. The roofing felt or paper II may be fed from a reel 22 over guide rollers 23 and 2B and below a guide roller 24, and then wound on a reel 26 to provide a roll Ill, such as is indicated in Fig. 1. Any desired or additional steps may be employed, such as removing surplus bonding or impregnating material, drying the sheets ll, applying talc or the like, or otherwise preventing layers of the rolls ill from sticking to each other.
As the sheet material i I is fed between the impregnating tank 20 and the winding reel 26, the piercings i5 are provided. These may be producedvby a pair of rolls 30 and 3| driven in opposite directions by any suitable means (not shown) at uniform peripheral speeds. Each of these rollers is provided with uniformly spaced needle-like projections 32 extending radially therefrom and arranged in substantially straight line rows in parallel, transverse, and diagonal directions with respect to the axis of each roller. The rows or projections on each roller are spaced, for example, approximately 0.7 of an inch apart with the pmjections of each longitudinal or transverse rows spaced the same distance apart. The projections of one roller, however, are staggered circumferentially and axially so as to space each piercing approximately 0.5 of an inch from the adjacent piercings, as indicated in Fig. 3. The rollers 30 and ii are arranged in axially parallel position and preferably are spaced so that the projections 32 of each roller will pierce completely through the sheet material II as it is passed between the rollers.
As indicated in Figs. 3 and 4, the piercings of each longitudinal or transverse row are directed in the same direction and the piercings of alternate rows extending in opposite directions, while adjacent piercings of each diagonal row extend in opposite directions. By forming the piercings I I in this manner, the sheets I I may be laid either sides down without closing, at the'most, over half of the piercings so as to prevent the venting of air or gas therethrough. Half of the piercings ii are produced by piercing from one face of the sheets and the other half by piercing from the opposite face thereof.
As illustrated in Fig. 4, the fibers ii of the sheet material II are compressed or rendered more compact adjacent the piercings I! by the needle-like projections 32 of rollers 30 and ll as the fibers l6 are separated or displaced. In this manner very few fibers are cut or torn away from other fibers so that the tensile strength of the sheets Ii is not materially reduced.
As many changes could be made in the above constructions and methods, and many apparently widely different embodiments and processes could be had without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawing, shall be interpreted as illustrative and not in a limiting sense.
What is. claimed is:
A roofing material comprising a sheet of felted fibrous material impregnated with and bonded together by an adhesive composition and being pierced at sufllciently frequent intervals subsequent to impregnation and in opposite directions from each ,face thereof to vent gas freely therethrough in either direction.
WILLIAM WALLACE CANDLER.