Chicken Wire Roof and Method of Insulation

The roof structure of an industrial building typically comprises rafter beams which extend parallel to one another across the building and slope from the center of the building down toward its sides, and purlins which extend parallel to one another and which extend across and are mounted on the rafter beams. Hard sheets of exterior roofing material extend over and are attached to the purlins. In the past, when a roof structure of an industrial building was to be insulated, sheets of insulation material were placed across the purlins and the sheets of hard roofing material were attached to the purlins through the insulation material. The relatively thin sheets of insulation material were applied to the roof structure by the workmen using the sheets of hard roofing material which were already installed in the roof structure as a working surface. Reels of insulation material were first unwound on the hard sheets of roofing material and the long sheets of insulation material were moved by hand over onto the exposed purlins adjacent the hard roofing material and the lengths of the sheets of insulation material extended across the lengths of the purlins. The sheets of insulation material were stretched to prevent sagging between the purlins, and the hard roofing material was then placed over the insulation material and connected to the purlins.

As set forth in my prior U.S. Pat. No. 3,559,914, it has now become common practice to extend the sheets of insulation material along the length of the purlins so as to prevent the seams between adjacent sheets of insulation material from being exposed inside the building. The new procedure as set forth in my patent has reduced hazards to workmen on the roof by maintaining the reels of insulation material in a relatively static and available position on the exposed purlins without exposing long lengths of a sheet of material to the wind, while the workmen remain on the sheets of hard roofing material, so that the occasions when the workmen might be tempted to walk or climb out on the purlins to place or adjust the sheets of insulation material have been reduced. The prior art, however, still does not provide the workmen with a safe working space beyond the installed sheets of hard roofing material adjacent the working area where the reels of insulation material are being placed on the exposed purlins.

The present invention comprises an insulated roof structure for an industrial building and a method and apparatus for more safely forming the roof structure. Reels of wire mesh and reels of sheet material are supported by a framework mounted on the purlins of a roof structure, with a reel of wire mesh and a reel of sheet material positioned over each space between adjacent ones of the purlins. The framework also supports a worker's platform so that a worker can be positioned out over the purlins beyond the hard surface formed by the hard sheets of roofing material. The free ends of the reels of wire mesh and of the sheet material extend from the worker's platform back to the installed roof area so that the wire mesh forms a safety net for the workers.

The wire mesh in the installed roof structure can be supported by a lattice of support straps extending through the purlins, by various connectors which connect the edges of the wire mesh to the purlins, or by other support means, and the wire mesh and sheet material form a supporting surface for additional insulation.

Thus, it is an object of this invention to provide an improved insulated roof structure for an industrial building or the like, wherein an improved support surface is located in the spaces between adjacent ones of the purlins in the roof structure and wherein large thicknesses of heat insulating material can be supported in the spaces between the adjacent purlins.

Another object of this invention is to provide a method and apparatus for reducing the hazards to workers on a roof structure as the roof structure is being assembled.

Another object of this invention is to provide an inexpensive insulated roof structure for an industrial building and a method and apparatus for safely, expediently and economically applying an insulated roof structure to a building.

Other objects, features and advantages of the present invention will become apparent upon reading the following specification, when taken in conjunction with the accompanying drawings.

FIG. 1 is a detailed perspective illustration of the improved roof structure, with portions broken away to show the arrangement of the parts.

FIG. 2 is a detailed perspective illustration of a small portion of the roof structure with portions being removed for clarity, showing an alternate connection feature for the wire mesh.

FIG. 3 is a detailed perspective illustration of a small portion of the roof structure with portions being removed for clarity, showing a second alternate connection feature for the wire mesh.

FIG. 4 is a partial perspective illustration of the apparatus for installing the wire mesh and sheet material.

FIG. 5 is a side cross-sectional view of the apparatus illustrated in FIG. 4.

Referring now in more detail to the drawings, in which like numerals indicate like parts throughout the several views, FIG. 1 illustrates the roof structure 10 which includes a plurality of spaced parallel inclined rafter beams 11 and spaced parallel purlins 12 (only one of each shown). The purlins 12 rest upon and are supported by the rafter beams 11, and each purlin includes a central web 14, lower flange 15, and upper flange 16. The lower and upper flanges terminate in minor flanges or rims 17 and 18 which extend back toward the central web 14. A plurality of openings 20 are formed in vertically spaced groups in the central web 14 of each purlin, with the groups of openings being spaced equally along the length of the purlin. Thus, each group of openings 20 in the purlin illustrated in FIG. 1 will be in alignment with a similar group of openings in an adjacent one of the purlins (not shown) in the roof structure.

A plurality of support straps 21 are located in the group structure, with each support strap 21 being threaded through an opening 20 in each purlin and through the others of the openings aligned with the openings 20 and the other purlins. The support strap 21 in FIG. 1 is illustrated as being threaded through the lowermost opening 20, but it will be understood that the support strap 21 can be inserted through any one of the vertically spaced openings 20. A retainer clip 22 is wedged in the opening through which the support strap extends so as to form a friction connection between the purlin 12 and the support strap 21. The support strap 21 is placed under tension so that it extends in a substantially flat plane between adjacent ones of the purlins. The plurality of support straps 21 form insulation support means in the roof structure, as will be understood from the following description.

A layer of wire mesh 24 is placed on the support straps 21. The layer of wire mesh 24 is of a width substantially equal to the spaces between the central webs 14 of adjacent ones of the purlins 12 so as to span the space between the central webs 14 of the purlins, and the length of the strip of wire mesh 24 extends along the length of the purlins. The particular wire mesh illustrated in the drawing is a "chicken wire" mesh and includes a six-sided net fabricated from wire, such as aluminum wire; however, it will be understood that various other net or mesh material can be used. For example, wire cloth or square mesh or other types of web, net or mesh material can be substituted, if desired. Also, the mesh can be selected from various types of materials, as may be desired for particular installations. In the particular embodiment illustrated, the chicken wire mesh 24 includes a side hem 25 that is substantially straight and which lies adjacent the central web 14 of the purlin 12. The support straps 21 support the mesh 24 at spaced intervals along the lengths of the purlins 12, and tension is applied to the mesh 24 so as to prevent the mesh from sagging extensively between adjacent ones of the support straps.

Sheet material 28 is placed upon the mesh 24. The sheet material 28 is of a width slightly larger than the spaces between the central webs 14 of adjacent ones of the purlins 12 so that the edges of the sheet material 28 tend to lie up against the central web 14 of the adjacent purlins. The length of sheet material extends along the length of the space between the adjacent purlins, and the sheet material 28 can comprise various materials, including a vinyl or other tough vapor impermeable substance, with the particular selection of the material in the sheet 28 depending upon the particular specifications of the roof structure.

A quantity of heat insulation material 29 is inserted in the spaces between adjacent ones of the purlins and onto the sheet material 28. The insulation material 29 can be in the form of blocks of solid material, sheets of material, loose material, or material that was initially loose when placed in the space but sprayed or otherwise mixed with adhesive as or after being inserted into the spaces so as to become substantially rigid. The sheet material 28, wire mesh 24 and support straps 21 form a relatively flat and strong support surface for the insulation material 29, so that a large quantity of the insulation material can be installed in the roof structure, as may be desired.

Additional sheet insulation material 30 is applied to the top surface of the upper flange 16 of the purlin 12, and the hard sheets 31 of roofing material is placed on the sheet insulation material 30 and connected to the purlins 12 by self-tapping screws 32 or other fasteners. The additional sheet of insulation material 30 functions to reduce the transfer of heat between the hard sheets 31 of roofing material and the purlins 12, and the insulation material 29 in the spaces between adjacent ones of the purlins function to inhibit the transfer of heat between inside the building and the hard sheets of roofing material 31 by means of convection and radiation.

As is illustrated in FIG. 2, the wire mesh 24 can be connected to the purlins 12 by alternate connection means, if desired. The central webs 14 of the purlins can have hooks or other fastening elements 35 punched therefrom and the hem 25 of the wire mesh can be inserted over the hooks. This system of supporting the edges of the wire mesh 24 can be used as a substitute for the support straps 21 or in addition to the support straps.

As is illustrated in FIG. 3, another alternate method of supporting the wire mesh 24 is illustrated, wherein a plurality of straps 36 are punched from the central web 14 of the purlin and hog clips 38 are threaded through the hem 25 of the wire mesh and through the straps 36. This system of connecting the wire mesh 24 to the purlins 12 also can be used in place of the support straps 21 of FIG. 1 or in addition thereto, if desired.

Since the strap openings 20, hooks 35 and straps 36 are vertically spaced, the wire mesh and sheet material can be positioned at different distances from the hard sheets of roofing material to accomodate different thicknesses of insulation and hold the insulation close to the hard sheets to roofing material.

As is illustrated in FIGS. 4 and 5, the apparatus 40 for installing the roof structure is placed upon the purlins 12 and includes a framework 41 mounted on guide means 42 which engage each purlin 12. A more complete disclosure of the framework 41 of the apparatus is disclosed in my copending U.S. patent application Ser. No. 649,911. A worker's platform 44 is supported by the framework 41, and support stanchions 45 and 46 extend upwardly from the framework on one side of the platform while support stanchions 47 and 48 extend upwardly from the framework on the other side of the platform. The support stanchions 45-48 function to hold reels of material over the spaces between adjacent ones of the purlins and the free ends of the reels of material extend downwardly into the spaces between the purlins. In the particular embodiment illustrated, two reels 50 and 51 are supported over each alternate space between adjacent ones of the purlins at the leading edge of the apparatus 40 and two similar reels 52 and 53 are supported over the other alternate spaces between adjacent ones of the purlins at the trailing end of the apparatus. The reels 50 and 52 are reels of wire mesh, while the reels 51 and 53 are reels of sheet material, and the free ends 55, 56, 57 and 58 from each reel is directed downwardly into the spaces between the purlins, with the free ends 57 and 58 passing downwardly about bar 59 and with the free ends 55 and 56 passing through the space 60 in the framework 41 below the worker's platform 44 and then downwardly into the spaces between the purlins. The apparatus 40 can be moved along the partially completed roof structure by winch means (not shown) pulling the apparatus from one end of the building or by other driving systems, and as the apparatus 40 moves along the lengths of the purlins, the wire mesh and sheet material is progressively and simultaneously paid out.

The free ends 55 and 57 of the wire mesh from the reels 50 and 52 are paid out beneath the free ends 56 and 58 of the material from the reels 51 and 53 so that the wire mesh is located below the sheet material in the final roof structure. As the wire mesh and sheet material are placed in the spaces between the purlins, the hard sheets 31 of exterior roofing material are applied to the roof structure by other workers working on the hard working surface of the already-completed portions of the roof, and the free ends 55 and 57 of the wire mesh from the reels 50 and 52 span the space between the hard sheets of exterior roofing material 31 to the worker's platform 44, so that the wire mesh 24 functions not only to support the insulation being installed in the roof structure but as a safety net for the workers on the roof, so that if a worker should accidentally slip down between the purlins, the wire mesh 24 would tend to support the falling worker, at least temporarily. Moreover, the open weave of the wire mesh 24 would aid the worker in grasping or catching onto some lifesaving supporting surface. The connecting features illustrated in FIGS. 2 and 3 of the drawings would tend to keep the wire mesh 24 from parting away from the purlins 12 and forming a space to allow the worker to drop from the roof structure.

It will be understood that the foregoing relates only to a disclosed embodiment of the present invention, and that numerous changes and modifications may be made therein within the scope of the invention as defined in the following claims.