Shingle with improved fastener pull-through resistance

Abstract

A laminated shingle resistant to fastener-head pull-through. The shingle includes an upper layer having a tab portion and a headlap portion, and a shim extending below the tab portion and part of the headlap portion. The part of the shim behind the tab portion forms, with the headlap portion, a dual thickness nailing zone. Since roofers sometimes drive fasteners such as roofing nails through the shingle behind the nailing zone, resulting in only a single layer available to resist fastener-head pull-through, a reinforcing tape which can have reinforcing strands is adhered to the bottom of the headlap portion immediately behind the rear edge of the shim. This effectively increases the size of the nailing zone without incurring the bulk, weight and cost of increasing the size of the shim.

Description

FIELD OF THE INVENTION

This invention relates to shingles which have improved resistance to pull-through of the heads of nails or other fasteners securing the shingles to a roof or to other surfaces.

BACKGROUND OF THE INVENTION

When shingles installed on a roof are subjected to high winds, the winds tend to bend the front or tab part of the shingles upwardly and may tear the shingles off the roof. This has been a long-standing problem, and various attempts have been made to prevent this undesirable event from occurring.

For example, in Venrick U.S. Pat. No. 2,161,440, issued Jun. 6, 1939, reinforcing strips are placed on the underside (or even on the upper surface) of shingles, to (among other things) increase the resistance of the shingles to being bent upwardly by the wind.

In Kalkanoglu et al. U.S. Pat. No. 6,758,019, a reinforcing layer is attached to the rear surface of the shingle below the nail fastening zone, again to increase the resistance of the shingle against having its lower edge bent upwardly by the wind.

Approaches such as those described in the above patents can be costly, and may add undesired bulk to the shingle, and do not adequately deal with another problem, namely, that when shingles are pulled upwardly by the wind (whether or not they are bent), the heads of the roofing nails or other fasteners securing the shingles to a roof tend to pull through the shingle material, causing failure of the shingle.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention, in one of its aspects, to provide a shingle with improved resistance against fastener pull-through.

In one aspect the invention provides a laminated shingle with improved resistance to fastener-head pull-through, comprising:

a) an upper layer having a tab portion having a front edge, and a headlap portion having a rear edge,

b) the headlap portion being adapted to be covered by another shingle and the tab portion being adapted to be exposed to the elements,

c) the tab portion comprising a plurality of tabs separated by spaces, the spaces having rear ends,

d) a lower layer located below said upper layer and extending from approximately said front edge of said upper layer to a position rearwardly of the rear edges of said spaces but forwardly of the rear edge of said upper layer, said lower layer defining with said upper layer a fastening zone of dual thickness for receiving fasteners having heads to hold said shingle on a roof, said fastening zone coinciding with part of said headlap portion,

e) and a reinforcing tape extending longitudinally of said shingle over at least a portion of said headlap portion rearwardly of said fastening zone, said tape being resistant to the head of a fastener being pulled therethrough, so that if a fastener is driven into said headlap portion rearwardly of said fastening zone, then if a wind pulls said shingle upwardly, said tape will resist the tendency of said shingle to pull past the head of said fastener.

Further objects and advantages of the invention will appear from the following description, taken together with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:

FIG. 1 is a perspective view of a shingle according to the invention;

FIG. 2 is an end cross-sectional view of the shingle of FIG. 1;

FIG. 3 is a plan view of a tape used in the FIGS. 1 and 2 shingle;

FIG. 4 is an end view of a modified shingle according to the invention;

FIG. 5 is a perspective view of a further modified shingle according to the invention;

FIG. 6 is an end view of another modified shingle according to the invention;

FIG. 7 is a perspective view of another modified shingle according to the invention; and

FIG. 8 is an end view of the shingle of FIG. 7.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Reference is first made to FIGS. 1 and 2, which show a shingle 10 having an upper layer 11. The upper layer 11 includes a set of tabs 12 which will be exposed to the elements when the shingle is properly installed on a roof, and a headlap portion 14 which is intended to be covered by another shingle when the shingle 10 is installed on a roof. The tabs 12 are covered by protective granules, as is well known, to protect them against the sun.

The shingle 10 has the appearance of a typical laminated shingle, with the tabs 12 being separated by spaces 16. To provide a laminated appearance, as well as necessary protection against the elements, the shingle 10 includes a lower layer or shim 20, which extends from the front edge 22 of the shingle rearwardly to a shim rear edge 24 spaced rearwardly of the rear ends 26 of the spaces 16. However, the rear edge 24 of the shim 20 is located well forwardly of the rear edge 30 of the headlap portion 14 of the upper layer 11.

The upper layer 11 and shim 20 together define a nailing zone 34, which extends from the rear ends 26 of the spaces 16 to the rear edge 24 of the shim 20. If desired, e.g. for esthetic reasons, the front edge 35 of the nailing zone 34 can be spaced slightly rearwardly of the rear ends of the spaces 16.

The nailing zone 34 is a zone of dual thickness. Roofers who install the shingles are instructed to drive their roofing fasteners, here shown as roofing nails 38, through the nailing zone 34, where the fasteners' shanks will extend through two layers of the shingle, namely, the upper layer 11 and the shim 20. If the nails are installed correctly, then if and when a wind bends or pulls the front edge 22 of the shingle upwardly, overcoming other shingle features like an adhesive dot or layer added to the underside of upper layer 11 or to the upper surface of shim 20 to resist lifting during wind actions, then the two layer thickness of the nailing zone 34 will provide increased resistance against the shingle material being pulled through or over the heads 36 of the roofing nails 38 used to attach the shingles to the roof. (The nailing zone 34 and nails 38 in use are normally covered by the shim and tabs of another adjacent shingle on the roof.) Thus, the nailing zone 34 coincides with part of the headlap portion 14.

Unfortunately, roofers are sometimes careless and tend to drive roofing nails or other fasteners through or into the headlap portion 14 rearwardly of the nailing zone 34. This can happen even if lines are marked in the shingle to define the nailing zone. Nails improperly installed in this way extend only through a single layer of the shingle, namely, the part of the headlap 14 behind shim 20, so if a wind or other environmental force (e.g. freeze and thaw cycles) pulls the shingle upwardly, there is only a single layer which will resist the pull-through of the nail-heads 36 to cause removal of the shingle from the roof. (This may be termed “nail-head pull-through”, meaning that the nail-heads are in effect being pulled through the shingle as the shingle is lifted by the wind. It will be realized that in this process, the nail-heads are generally stationary or fixed and the shingles move.) Thus, failure of the shingle is more likely to occur if the nails are not accurately placed.

Therefore, the invention in a preferred embodiment provides a layer of thin, strongly adhesive tape 42 extending along the lower surface of the upper layer 11. The front edge 43 of tape 42 is located immediately rearwardly of the rear edge 24 of the shim and hence immediately rearwardly of the normally defined nailing zone 34. The tape 42 may typically be a conventional strong packaging tape of the kind used by stores and movers to seal boxes. The tape 42 is preferably strongly self-adhesive so that it adheres firmly to the lower surface of the upper layer 11 with strong resistance to being pulled off. The tape 42 may be fiber reinforced, with reinforcing strands running in multiple directions (e.g. cross-wise and lengthwise of the tape) as shown at 44, 46 in FIG. 3. With the reinforcing strands 44, 46, which are preferably closely spaced, the tape 42 will be resistant to tearing. Therefore, when the shingle experiences a lifting force from the wind, the tape 42 will strongly resist being pulled past the nail-heads 36. However, when the nails 38 are applied to install the shingle, if the tip of a nail encounters a strand, then because the nail tip is tapered, the strand will simply move to one side allowing the nail to penetrate the tape 42. The strands 44, 46 may be of any conventional strong material used in packaging tape.

Because the tape 42 is located rearwardly of the nailing zone 34, the nailing zone is effectively made wider without the need for extending the shim 20 rearwardly. Therefore, increased resistance against nail-head pull-through, and against shingle loosening and tearing, is provided, while avoiding the increased weight and greater bulk of a larger shim which could otherwise need to be used to achieve these objectives. The ability to use a smaller shim facilitates shipping, storage and handling of the shingles (they can be thinner over part of their width, and lighter then would otherwise be necessary), and also reduces cost since a larger shim would normally be more expensive then applying the tape 42.

Although the reinforcement against nail-head pull-through has been shown as a tape 42 applied to the undersurface of the upper layer 11, if desired the tape 42 can be embedded in the upper layer 11 during manufacturing of the upper layer, e.g. before the mat which forms the upper layer 11 is impregnated with asphalt. Alternatively, the tape 42 may be of an open weave construction so that it can sink into the hot asphalt which is applied to the top and bottom of the shingles during manufacturing and so that the tape 42 will be embedded in the upper layer 11 (either near the top or the bottom thereof). In that case, the tape 42 need not be self-adhesive.

Although it has been assumed that the shingles 10 are fastened to the roof with nails, other types of fasteners can be used, e.g. screws, or staples, brads or a combination of screws, nails, brads and staples.

The tape 42 can be any woven or non-woven, or rolled or extruded, material, so long as it is a strip of strong material. If desired, when the tape 42 is placed on or near the top of upper layer 11, then the tape 42 can extend forwardly across all or part of the nailing zone 34, as shown at 42′ in FIG. 4, where primed reference numerals indicate parts corresponding to those of FIGS. 1 to 3. An advantage of this is that tape 42′ provides increased resistance against shingle tearing and nail-head pull-through even when the nails are correctly installed in nailing zone 34′ since there are now two shingle layers plus a third layer (the tape layer) to resist nail-head pull-through. Of course the wider tape 42′ adds cost over the tape 42, but if the tape 42′ is on the upper surface of upper layer 11, then the granules normally used on shingle surfaces (for ultra-violet protection) will not or may not stick to tape 42′. Therefore fewer granules are needed for the shingle 10′, thus reducing the cost of the shingle.

If desired, the tape 42 can be attached to the underside of layer 11 and tape 42′ on the topside of layer 11 simultaneously. This provides two extra layers to resist shingle tearing and nail or fastener-head pull-through.

This invention applies equally to shingles made of oxidized asphalt or modified asphalt, or shingles made from a combination of both. Since shingles made with modified asphalt are soft, this invention adds extra protection for such products.

While the invention has been described as applying to laminated shingles, it will be realized that it also applies to specialty shingles, such as hip and ridge shingles, which can be exposed to similar wind forces and actions. Since hip and ridge shingles are sometimes made with modified forms of asphalt, this invention adds extra protection for such products.

In another aspect, the invention provides improved resistance against fastener head pull-through for a single layer shingle, as shown in FIG. 5, where double primed reference numerals indicate parts corresponding to those of FIGS. 1 to 4. FIG. 5 shows a single layer shingle 10″, corresponding to the upper layer 11 and 11′ of FIGS. 1 to 4. As before, the shingle 10″ has a set of tabs 12″ at its front and a rear headlap portion 14″ which will be covered by another shingle. Since there is no shim, a nailing zone 34″ is somewhat arbitrarily marked on the upper surface of the shingle 10″. The front edge 50 of the nailing zone 34″ is located at the rear ends 26″ of the tab spaces 16″. The rear edge 52 of the nailing zone 34″ is spaced rearwardly from the front edge 50. Preferably the nailing zone 34″ does not extend too far rearwardly on the shingle, to reduce the leverage which upwardly directed wind generated forces may have on the fasteners applied to the nailing zone 34″.

In the same manner as described previously, a reinforcing tape 42″ may be adhered or otherwise fastened to the bottom surface of the shingle 10″. The front edge 54 of the reinforcing tape 42″ should not extend forwardly of the read ends 26″ of the spaces 16″, since the spaces 16″ should not be blocked. The rear edge 56 of the reinforcing tape 42″ extends rearwardly of the rear edge 52 of the nailing zone 34″.

Thus, when a roofer drives fasteners such as roofing nails into the nailing zone 34″, then if the roofer is careless and positions some fasteners slightly rearwardly of the rear edge 52 of the nailing zone, these fasteners will penetrate reinforcing tape 42″, which will offer resistance to fastener head pull-through. Therefore, the tape 42″ offers the dual advantage of insuring that there are two layers in the area of the nailing zone to resist fastener head pull-through, and that in an area behind the nailing zone 34″, there are still two layers to resist fastener head pull-through. Therefore the nailing zone 34 has been effectively widened in a light, cost-effective manner, and without interfering with the tabs 12″.

While the reinforcing tape 42″ has been shown in FIG. 5 as located on the bottom surface of the shingle 10″, it may instead be located on the top surface of the shingle, as shown in FIG. 6 where triple primed reference numerals indicate parts corresponding to those of the previous figures. Preferably the tape 42′″ is inset into the upper surface of shingle 10′″ so as not to create a “bump” in the upper surface of the shingle. As before, the tape 42′″ does not extend forwardly of the rear ends 26′″ of the tab spaces, but does extend rearwardly of the rear edge 52′″ of the nailing zone 34′″. As before, this increases the width of the nailing zone in a front to rear direction and adds an extra layer (which is thin and strong) to resist fastener head pull-through.

In some specialty single layer shingles, there may be no tabs, in which case the shingle will simply be a single layer sheet without cutouts, as shown at 10″″ in FIGS. 7 and 8 (where quadruple primed marks indicate parts corresponding to those of FIGS. 1 to 6). The shingle 10″″ comprises a single sheet 11″″ having a front portion 60 covered by protective granules 62, and a headlap portion 14″″ which is normally covered by another shingle when the shingle 10″″ is installed on a roof. The headlap portion 14″″ includes at its front a nailing zone 34″″, as before.

As in the FIGS. 5 and 6 embodiment, a reinforcing tape 42″″ is adhered or otherwise fastened to the bottom surface of the shingle 10″″. The front edge 54″″ of the reinforcing tape 42″″ should not extend forwardly of the nailing zone, since the portion of the shingle forwardly of the nailing zone 34″″ is exposed to the elements and therefore should not have nails or other fasteners driven through it. However, the rear edge 56″″ of the reinforcing tape 42″″ extends rearwardly of the rear edge 52″″ of the nailing zone 34″″.

Therefore, as in the FIGS. 5 and 6 embodiments, if the roofer is careless and positions some fasteners slightly rearwardly of the rear edge 52″″ of the nailing zone, these fasteners will penetrate the reinforcing tape which will offer resistance to fastener-head pull-through. Therefore, the tape 42″″ again offers the dual advantage of ensuring that there are two layers in the area of the nailing zone to resist fastener-head pull-through, and that in an area behind the nailing zone 34″″, there are still two layers to resist fastener-head pull-through.

If desired, the tape 42″″ may be located on the top surface of the shingle, in the same manner as shown in FIG. 6.

While preferred embodiments of the invention have been described, modifications may be made if desired.

Claims

1. A laminated shingle resistant to fastener-head pull-through, comprising:

a) an upper layer having a tab portion having a front edge, and a headlap portion having a rear edge,

b) the headlap portion being adapted to be covered by another shingle and the tab portion being adapted to be exposed to the elements,

c) the tab portion comprising a plurality of tabs separated by spaces, the spaces having rear ends,

d) a lower layer located below said upper layer and extending from approximately said front edge of said upper layer to a position rearwardly of the rear edges of said spaces but forwardly of the rear edge of said upper layer, said lower layer defining with said upper layer a fastening zone of dual thickness for receiving fasteners having heads to hold said shingle on a roof, said fastening zone coinciding with part of said headlap portion,

e) and a reinforcing tape extending longitudinally of said shingle over at least a portion of said headlap portion rearwardly of said fastening zone, said tape being resistant to the head of a fastener being pulled therethrough, so that if a fastener is driven into said headlap portion rearwardly of said fastening zone, then if a wind pulls said shingle upwardly, said tape will resist the tendency of said shingle to pull past the head of said fastener.

2. A shingle according to claim 1 wherein said upper layer has a lower surface, and said tape is self-adhesive and is adhered to the lower surface of said upper layer.

3. A shingle according to claim 2 wherein said tape has a front edge which is located immediately rearwardly of the rear edge of said lower layer.

4. A shingle according to claim 1 wherein said upper layer has an upper surface, and wherein said tape is positioned on or near said upper surface.

5. A shingle according to claim 4 wherein said tape extends forwardly to said rear ends of said spaces.

6. A shingle resistant to fastener head pull-through, comprising:

(a) a layer having a tab portion having a front edge, and a headlap portion having a rear edge,

(b) the headlap portion being adapted to be covered by another shingle and the tab portion being adapted to be exposed to the elements,

c) the tab portion comprising a plurality of tabs separated by spaces, the spaces having rear ends,

(d) said layer having a fastening zone extending from approximately the rear ends of said spaces rearwardly, said fastening zone having a rear edge spaced forwardly of the rear edge of said headlap portion, said fastening zone being adapted to receive fasteners having heads to hold said shingle on a roof,

(e) and a reinforcing tape extending longitudinally of said shingle over at least a portion of said headlap portion in said fastening zone, said reinforcing tape extending rearwardly of the rear edge of said fastening zone and not extending forwardly of the rear ends of said spaces, said tape being resistant to the head of a fastener passing therethrough.

7. A shingle according to claim 6 wherein said reinforcing tape is located on a lower surface of said shingle.

8. A shingle according to claim 6 wherein said reinforcing tape is inset into an upper surface of said shingle.

9. A shingle resistant to fastener-head pull-through, comprising:

(a) a layer having a front portion and a headlap portion behind said front portion, said front portion having a front edge, said headlap portion having a rear edge, and there being a dividing line between said front portion and said headlap portion,

(b) the headlap portion being adapted to be covered by another shingle, and the front portion being adapted to be exposed to the elements,

(c) said layer having a fastening zone extending from said dividing line rearwardly, said fastening zone having a rear edge spaced forwardly of the rear edge of said headlap portion, said fastening zone being adapted to receive fasteners having heads to hold said shingle on a roof,

(d) and a reinforcing tape extending longitudinally of said shingle over at least a portion of said headlap portion in said fastening zone, said reinforcing tape extending rearwardly of the rear edge of said fastening zone and not extending forwardly of said dividing line, said tape being resistant to the head of a fastener passing there through.

10. A shingle according to claim 9 wherein said reinforcing tape is located on a lower surface of said shingle.

11. A shingle according to claim 9 wherein said reinforcing tape is set into an upper surface of said shingle.