CA2007063A1 - Insulation system for metal structures - Google Patents

Abstract

Abstract of the Disclosure An insulation mat for use in insulating the roof or side walls of a metal building includes a fluid-impermeable, flexible plastic top skin and a fluid-impermeable, flexible plastic bottom skin each of which are generally rectangular with a width dimension of approximately 4 feet and a length dimension of at least 100 feet such as would come from a continuous roll. The top and bottom skins are aligned with each other and their leading edge and sides heat sealed so as to define an interior cavity. The interior cavity is filled with an insulation material and when prepared to the desired length, the trailing edge is heat sealed so as to complete the enclosed insulation mat. The fluid-impermeable nature of the top and bottom skins and the fact that all four sides are heat sealed into a fluid-tight enclosure allow the insulation material on the inside to remain dry and unaffected by outside weather conditions. These insulation mats are sized so as to be suitable for applying on standard spacing to the roof or side walls of a metal building. The side edges of each insulation mat are heat-sealed into a tab or flange which may be stapled or otherwise joined to the flange of adjacent mats in order to create, in effect, a one-piece insulation covering for the entire roof.

Description

INSULATION SYSTEM FOR METAL ~UILDINGS

Backaround of the Invention The present invention pertains g~nerally to insulation for metal buildings such as farm outbuildings, warehouses and the like. More particularly, the present invention pertains to an insulation system for a metal building wherein the insulation material is encased in order to prevent moisture from adversely affecting the insulation material and its insulating properties.
A common and widely used construction technique for metal buildings consists of an assembly of metal framework components such as beams, columns, rafters, metal siding and metal roofing that are all preengineered and manufactured off site in order to meet the given specifications required for the particular building. Thermal insulation is almost always another necessary component in order to allow for a finished structure that is economical to heat and/or cool as required based upon its end use and the desired internal atmosphere. For economic reasons, it is important for all com~onents to be designed for quick and efficient on-site construction as well as to meet the physical design requirements.
A typical design and assembly sequence for such metal buildings includes as a first step erecting and fastening large steel support beams to concrete footers and foundation walls. Typically large bolts are anchored in the cured concrete and these bolts are used to secure the support beams. The next step is to assemble and fasten steel cross members to the erected beam structure. Once the steel frame is fabricated, if the building is to be insulated, the next step is to unroll the rolls of fiberglass insulation (batting) over the cross members. Each successive strip of insulation is connected to the adjacent strip by taping or stapling together the edges of each unrolled length. The next step is to place the exterior metal siding or roofing ~,~

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over the insulation and drive screws through the metal siding or roofing and the insulation into the metal cross members. Various trim pieces, gutters, etc. are put in place last.
There are two major factors that limit the effectiveness of the insulation in this type of construction. First, the steps of unrolling and applying insulation and assembling the sheet metal siding or roofing over the insulation typically takes place over several days, weeks or even 1~ months, depending upon the particular size and site of the building. Invariably, there are changing weather conditions during this period of time that will expose the fiberglass insulation to moisture in the form of rain, snow, etc.
Since the insulation is of an open fibrous nature, it readily soaks up such moisture. This can be a severe problem because a moisture impervious vapor barrier is typically on the underside of the insulation (interior of the building) and serves to hold the moisture in by preventing any gravitational draining. Once the sheet metal is applied over the top of the insulation, the water is effectively trapped in the insulation where it can remain - almost indefinitely. The insulating properties of the fiberglass are greatly reduced when the fiberglass is moisture-laden. Further, since the fiberglass is merely draped over the frame structure cross members, the weight of water from a significant water build-up can cause insulation to sag, tear and delaminate.
The second factor is the necessity for driving screws through the outer sheet metal, through the insulation and into the cross members of the structure in order to complete the assembly. This particular approach limits the thickness of the insulation which can be used. Typically, no more than six inches of thickness can be used and more commonly thinner insulation is used to ease assembly. Since the insulating value (R-value) of fiberglass is increased greatly by increasing the thickness, metal structures such ' 200706~

as those described herein are limited to a relatively inefficient insulation compared to most residential home construction where insulation thicknesses of up to 12 inches or greater are commonly used. To further compound this limitation, the insulation thickness is even less at the point where it is pinched (compressed) by the screws joining the sheet metal to the cross members of the frame.
A variety of metal building insulation concepts and structures have been patented over the years and the following list is a sampling of such concepts and structures.
Patent No. Patentee Issue Date 4,700,521 Cover 10/20/1987 4,445,305 Orie, Sr. 05/01/1984 4,434,592 Reneault et al. 03/06/1984 4,399,645 Murphy et al. 08/23/1983 4,303,713 Clemensen et al. 12/01/1981 4,279,112 Bertrand 07/21/1981 4,143,495 Hintz 03/13/1979 4,120,123 Knudson 10/17/1978 3,729,879 Franklin 05/01/1973 Cover discloses thermal insulation for walls, ceilings and floors of building structures comprising alternate layers of low emissivity sheets and batts of low-heat conductive material laminated together to form a single insulation batt. The low-heat conductive material is preferably fiberglass or rock wool. The low emissivity sheets may be a metal foil or a metal which is vacuum deposited on a substrate. The alternating layers are laminated together using a solvent-based pressure-sensitive adhesive.
Orie, Sr. discloses a secondary roof system for application over existing metal roofs of the cleat panel or structural panel type. Elongated expanded polystyrene insulation panels are inserted in the roof pans of the ...:~
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;, existing metal panel roof. A plurality of interlockedsecondary metal roof panels having the same width as the original roof panels is disposed over the insulation panels and the interlocking edges attached to the upwardly projecting joints of the existing metal roof panels.
Reneault et al. discloses a heat and sound-insulating structure for boarding or other non-loading walls. The disclosed structure comprises a heat-insulating panal maintained between an inner metal revetment and an outer metal revetment. The revetments are provided with ribs which project into the panel and the ribs of the two revetments are perpendicular to one another. A thin core of insulating material is applied against one of the revetments by a thin and sold metal sheet.
Murphy et al. discloses bladder insulation which is adapted to be inserted within the wall cavities of existing buildings in order to provide for high-quality insulation having a high R-value. The invention describes a bladder or impervious bag constructed of two thermoplastic sheets of -material hermetically sealed at both ends and on each of the sides. The preferred film used herein is urethane, although - polyethylene of 4-15 mils in thickness may be employed on ~-the inside and/or on the outside of the bladder. This bag can be inflated within the wall cavity and filled with various insulative materials and/or pressurized with various fluorinated hydrocarbon gases. The invention also includes a means for inserting the bladder within the wall of the structure and rigidifying the bladder by adherence to studs or a polymerization technique to form a polyisocyanate on the interior side of the bladder.
Clemensen et al. discloses a roof-insulating structure and a method of making the same. This particular invention is intended for improving the insulation quality of a metal building roof. The disclosed structure includes a self-supporting medium density thermal insulation blanket having elongated slits and notches in the top thereof so that the blanket can be folded into a U-shaped configuration. The U-shaped blanket is received on the tGp and the sides of a pair of adjacent and parallel roof purlins and spans the width therebetween. The U-shaped configuration of the blanket provides means for providing a thick blanket of low-density thermal insulation inside thereof and between the purlins for increasing the insulation R factor of the insulated roof.
Bertrand discloses a method for improving the thermic insulation of a building with the rigid frame structure.
The method is used to insulate a metal building which has a rigid frame structure comprised of metal columns, beams, braces and rafters which are rigidly fixed to each other.
There is a sheet metal roof and sheet metal wall panels which are secured to the frame by metallic fasteners. A
thick layer of insulating material is first placed on the inner surfaces of the roof and wall panels before they are secured to the rigid frame and the insulating material is then pinched between said panels and the frame members.
Then, insulating covers are glued in place on each of the members of the rigid frame to completely cover all exposed portions of such members within the building and under the layer of insulating material. The purpose of this assembly is to reduce heat loss and greatly alleviate the formation of condensate moisture within the building.
Hintz discloses a sound-absorbing panel having a front and a rear sheet, the front sheet being corrugated and perforated, and including a filler of particles of elastic material between the two sheets.
Knudson discloses a structural cap and composite structure for buildings and similar structures. The invention dis~loses a structural cap which fastens along its opposite side edges to the seam structure joining a generally channel-shaped structural panel to adjacent similar panels in order to form a four-sided, closed, generally tubular, composite structure that has considerably ~,, . ~ - -:

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greater load-bearing strength than the connected panel alone. When temperature differentials between the inside and outside are a factor, a body of heat insulation is provided in the closed space as well as heat insulation between the fastening side edges of the cap and connecting seam structures. Each structural cap is preferably made as a one-piece body of sheet metal that is shaped to have an intermediate cover portion that overlies the bottom of the panel and side edge portions on opposite sides o~ the cover portion including side wall sections that recess the cover portion inwardly of the outside of the panel and reinforces side walls of the panel.
Franklin discloses an insulation assembly for a building structure and a device for quickly and easily securing the insulation to wall joists so as to eliminate the job of stapling insulation to the joists. The present insulation assembly consists of a soft wooley insulation material such as fiberglass placed between paper or equivalent sheets which are glued together along their side edges. The side edges on one outer side having a pressure-sensitive adhesive applied thereto which is covered by removable protective strip of paper that can be peeled off to expose the adhesive for placement of the insulation assembly against the wall joists.
Although these listed references clearly disclose a number of insulation concepts for use with metal buildings, none provide the specific construction which is provided by ~-the present invention. Those disclosures which provide hothing more than sandwiching a thickness of insulation between metal surfaces or a sheet metal panel and a frame represent the typical type of prior device that this invention improves upon. The enclosed insulation mats of the present invention are simply not disclosed or suggested by the listed references.
For example, in Murphy et al. which discloses a flexible bladder which is filled with insulation and disposed between "", , , side walls of a building, that would not be appropriate for the metal building construction in view of the fact that the insulation assembly is shaped by the space between the side walls and does not come as an enclosed panel in roll form.
The entire structure of Murphy is geared to insulating a space which is otherwise virtually inaccessible and thus a deflatable bladder is required. None of these aspects are applicable to the metal building construction which is completely open and able to receive insulation panels.
Another reference of interest is Bertrand, but here, in a method considerably different from the present invention, a thick layer of insulating material is actually fixed to the inner surfaces of the sheet metal roof and wall panels before they are bolted onto the rafters of the frame. It is clear from the disclosure that this thickness of insulating material is not encased in a moisture-impermeable envelope but merely covered with insulating covers to protect exposed portions. The only aspect of Bertrand which in any way relates to the concerns over moisture is the described condensation phenomenon and to overcome this particular problem, the exposed parts of the frame structure of the building are insulated with the use of rigid coverings 19 which are made of insulating material.
Finally, the Franklin reference is possibly of some particular interest for its disclosure of an insulation assembly which includes some type of insulation material such as fiberglass placed between long panels of a material such as paper whose outer edges are joined together so as to create a pocket for the insulation material on the interior. One side of the sealed edge is provided with a pressure-sensitive adhesive strip protected by a plastic-coated paper strip. This allows this particular insulation assembly to simply be stuck on or between floor, wall or ceiling studs or joists. This particular technique is intended only to substitute for the stapling procedure which the patent suggests takes a great amount of time, and that technique is to be replaced by an insulation assembly that has self-contained means to attach the insulation to the studs or joists of a building. Again, this particular invention focuses on a situation and problem completely unrelated to the present invention and attempts to satisfy or overcome that problem by a structure and method which is different from the present invention.
An improvement to these aforementioned concepts and structures and one which overcomes the various problems with some of the present insulation methods for metal buildings is offered by the present invention. The present invention provides an improved thermal insulation system for insulating preengineered metal buildings. The thermal insulation system consists of fiberglass batting enclosed in any of a variety of heat-sealable plastic films or metal - foil/film laminates as dicated by the desired thermal performance or physical characteristics of the insulation. ;~
The insulation system of the present invention serves to eliminate the major problem of water saturation that often occurs during installation of the current and most widely used insulation systems. Moisture saturation is a condition that can greatly reduce the insulation R factor and virtually offset the entire value of the insulation. The system of the present invention also eliminates the handling and health concerns associated with exposed fiberglass materials. ;

Summary of the Invention , An insulation mat for use in insulating the roof or side wall of the metal building according to one embodiment of the present invention comprises a fluid-impermeable top skin having a gener.ally rectangular peripheral edge, a fluid-impermeable bottom skin having a generally rectangular peripheral edge, the top and bottom skins being sealed together in the pro~imity of their peripheral edges and defining thereby a sealed interior cavity therebetween and insulation material disposed within the interior cavity.

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2007~63 one object of the present invention is to provide an improved insulation mat for metal buildings.
Related objects and advantages of the present invention will be apparent from the following description.

Brief Description of the Drawing~
FIG. 1 is a partial perspective view of a metal building with insulation mats applied to the roof according to a typical embodiment of the present invention.
FIG. 2 is a partial end elevational view in full section of the roof portion of the FIG. 1 building.
FIG. 3 is a partial side view of the roof portion as taken along plane 3~3 in FIG. 2.
FIG. 4 is a partial perspective view of an insulation mat comprising a portion of the FIG. 1 building.
FIG. 5 is a section view of the FIG. 4 insulation mat showing its attachment to an adjacent insulation mat.
FIG. 6 is a partial, full section view of an alternate joining technique for adjacent insulation mats according to the present invention.

Description of the Preferred Embodiment For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiment illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated device, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one s~illed in the art to which the invention relates.
Referring to FIG. 1, there is illustrated in partial and diagrammatic form a metal building 20 which includes a partially completed roof 21. Roof 21 includes steel cross ,~. , ~

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members 22, insulation mats 23 and ribbed or corrugated sheet metal roofing panels 24. The building 20 includes a lower base 27, upright corner columns 28, outer side braces 29 and interior columns 30.
It is to be understood that building 20 is intended to merely represent one possible construction for a metal building of the type employing insulation material above the -~
roof frame and below the sheet metal roof covering. While virtually any style of metal building will be suitable for 10 the present invention, the specifics of the roof style and side wall construction are important. The roof structure illustrated is believed to be the most representative of the roof style of metal buildings for which the present invention would be used.
Referring to FIG. 2, there is illustrated a partial end view, in full section, of roof 21 as disposed across roof support beams 33, a joined pair of which is illustrated.
There is one support beam secured to the top of each of the columns 28 and 30. The support beams are arranged in pairs 20 extending inwardly and upwardly from opposite sides of the building. Each aligned pair of support beams is jointed at abutment line 34 which is parallel with the apex of the roof which in the exemplary embodiment is a gable roof design.
Although there are four corner columns, the number of 25 interior columns 30 will depend upon the size of the building, predominantly controlled by the length dimension.
However, if the building is particularly high, a greater number of interior columns may be desired as would be expected simply based upon the area between columns.
The support beams extend laterally and generally parallel to each other and the cross members run longitudinally.the length of the building. The cross members 22 which are generally parallel to each other will vary in number depending on the size of the building. The 35 cross members are arranged substantially perpendicular to the support beams. Each cross member is a generally U-shaped channel with the lower side joined to the support beams and the upper, opposite side providing the support surface for the insulation mats 23. The mats are arranged as generally rectangular members which extend longitudinally in a direction and plane substantially parallel to the support beams and substantially perpendicular to the cross members. The final components of roof 21, with the exception of attachment hardware are roofing panels 24.
These generally rectangular panels are arranged to extend longitudinally in the same direction as the insulation mats and substantially parallel to the mats and to the plane of the mats.
FIG. 3 provides a side edge view of the FIG. 2 structure as viewed along line 3-3. As illustrated, the roofing panels 24 are disposed with generally rectangular corrugations 35 and are joined edge to edge in overlapping relation. A plurality of insulation mats 23 are likewise arranged in a side-by-side relation for the full length of the building. As will be described in greater detail hereinafter, each insulation mat is formed by filling an enclosed, water-impermeable envelope with insulation material. The sealed edges of the enclosed envelopes are joined together in order to create an integral insulation covering for at least one-half of the entire roof.
Referring to FIG. 4, a portion of one insulation mat 23 is illustrated. Mat 23 has a length (L) which varies depending on the roof size or wall height but a width (w) which is typically 4 feet for the roof or 6 feet for a side wall. The thickness (t) will range from 1-1/2 inches to 6 inches. Sealed edge 36 extends on the illustrated side for the full length and the opposite side which is not illustrated al~o has a sealed edge. Enclosed envelope 37 has a top skin 38 and an opposite side bottom skin 39.
Disposed between the top and bottom skins is suitable insulation material 40. In this arrangement it is to be understood that the front edge 41 is sealed as will be the rear edge once the length of each individual insulation mat 23 is determined. The individual insulation mats may be cut from a larger rolled strip which may be formed in any length such as a 100-foot length or more and cut to the desired length at the site and then sealed on its trailing edge.
Four-foot wide rolled strips are used for the mats for the roof and six-foot wide strips are used for the side wall mats. A suitable material for top skin 38 and bottom skin 39 is any of a variety of heat-sealable plastic films or metal foil/film laminates such as polyethylene film, polypropylene film, metalized plastic film etc., which are suitable moisture barriers. The interior insulation material may be fiberglass batting or loose, discrete -insulation such as cellulose, or polyurethane. The double-skin, filled envelope design enables the plastic film to be dispensed from rolls and the edges sealed as the insulation is inserted between the two skins. Once the desired length is selected, the trailing edge is sealed, the leading edge having already been sealed at the start of the process of forming the mat 23.
As illustrated in FIGS. 5 and 6, mat 23 is formed with the outer side edges of the top skin 38 and bottom skin 39 pinched together and sealed. In the exemplary embodiment, these outer side edges are heat-sealed and the double thickness of sealed edge 36 may be used to join adjacent mats to each other, if desired, as illustrated in FIG. 5.
This joining step may be achieved by the use of stables or tape or adhesive which is applied as the mats 23 are positioned over the cross members 22. Adhesive may also be used to join the outer side edges of the skins into sealed edge 36. Either with or without being joined together with staples or adhesive or even by heat-sealing, adjacent mats may be closely positioned by turning the abutting sealed edges upwardly or downwardly and pushing the mat bodies close together, as illustrated in FIG. 6. In the preferred approach, the tabs (sealed edges 36) which are formed by heat-sealing the top and bottom skins are turned upwardly and adjacen~ tabs stapled together. This stapling step helps to prevent individual mats from shifting and becoming misaligned during assembly as part of the roof. However, the final assembly step is to drive screws 42 through the outer roofing panels, through the insulation and into the metal cross members. The remainder of the building structure is then completed such as attaching trim pieces, gutters, etc. It is also to be noted that the described apparatus and method with regard to the roof structure is equally applicable to siding panels and the procedure which has been described would be virtually the same.
What is thus provided by the present invention is a very manageable insulation system for metal buildings which not only provide the desired insulation, but which provides that insulation in a simple, efficient and cost-effective manner. First, by encasing the fiberglass insulation or loose, discrete insulation within a fluid-impermeable flexible plastic film envelope, any handling concerns or exposure to the fiberglass is eliminated. This is an advantage not only at the work site but in handling and shipping of the fiberglass to bring it to the work site.
Another advantage is that the encased insulation may be stored at the work site without concerns with regard to environmental conditions and may be installed onto the cross member without particular concern that if the building is not completed, moisture may attack the insulation making it virtually worthless. The presence of the sealed edges on either side of the insulation mat provides a number of desirable options for joining adjacent mats together as well as for assembly of mats to the structure. The encased insulation may be made in virtually any length and actually dispensed in a prefab roll. All of these particular benefits provide a most desirable insulation concept which is not provided by any of the presently existing or known insulation techniques.

;~007063 Another option with the present invention is to ~:
completely encase and seal closed the panel of insulation and then puncture one skin and draw a vacuum. Since the encased fiberglass (or loose, discrete insulation) is 5 flexible and compressible, a much larger thickness can be :
encased and reduced in thickness by drawing the vacuum. :~
While the finished thickness may be the same as the "as-received," nonencased fiberglass, the R-value will be much higher. . :
While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiment has been shown and described and that all changes and modifications that come within the spirit of the invention are desired to be protected.

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Claims (16)

1. An insulation mat for use in insulating the roof or side wall of a metal building comprises:
a fluid-impermeable top skin having a generally rectangular peripheral edge;
a fluid-impermeable bottom skin having a generally rectangular peripheral edge;
said top and bottom skins being sealed together in the proximity of their peripheral edges and defining a sealed interior cavity therebetween; and insulation material disposed within said interior cavity.

2. The insulation mat of claim 1 wherein the sides of the generally rectangular peripheries of the skins are sealed together so as to form a sealed flange extending substantially the full length of said insulation mat.

3. The insulation mat of claim 2 wherein the length dimension of the insulation mat is at least ten times the width of the insulation mat.

4. The insulation mat of claim 3 wherein the top and bottom skins are fabricated of polyethylene film and said insulation material is fiberglass.

5. An insulation system for use in insulating a metal building comprising:
a plurality of generally rectangular insulation mats arranged longitudinally in side-by-side relation, each insulation mat being joined to each adjacent insulation mat and each insulation mat including:
a fluid-impermeable top skin having a generally rectangular peripheral edge;
a fluid-impermeable bottom skin having a generally rectangular peripheral edge;

said top and bottom skins being sealed together in the proximity of their peripheral edges and defining a sealed interior cavity therebetween; and insulation material disposed within said interior cavity.

6. The insulation system of claim 5 wherein the top and bottom skins of each insulation mat are fabricated of metalized plastic film and the insulation material is fiberglass.

7. The insulation system of claim 5 wherein the sides of the generally rectangular peripheries of the skins of each insulation mat are sealed together so as to form a sealed flange extending substantially the full length of the corresponding insulation mat.

8. The insulation system of claim 7 wherein the length dimension of each insulation mat is at least ten times the width dimension of the corresponding insulation mat.

9. The insulation system of claim 8 wherein the top and bottom skins of each insulation mat are fabricated of polyethylene film and the insulation material is fiberglass.

10. An insulated metal building comprising:
a predominantly metal frame including a plurality of support columns and a plurality of angled supports disposed atop said support columns;
a plurality of support members extending substantially the entire length of the building and supported by said angled supports;
a plurality of elongate insulation mats arranged in side-by-side relation and extending in a direction substantially perpendicular to said support members, each insulation mat including:

a fluid-impermeable top skin having a generally rectangular peripheral edge;
a fluid-impermeable bottom skin having a generally rectangular peripheral edge;
said top and bottom skins being sealed together in the proximity of their peripheral edges and defining a sealed interior cavity therebetween; and insulation material disposed within said interior cavity; and a plurality of roofing panels disposed over said insulation mats and secured in place by a plurality of fasteners extending through said panels and through said mats and being received by said plurality of support members.

11. The building of claim 10 wherein the top and bottom skin of each insulation mat are fabricated of metalized plastic film and said insulation is fiberglass.

12. The building of claim 10 wherein the sides of the generally rectangular peripheries of the skins of each insulation mat are sealed together so as to form a sealed flange extending substantially the full length of the corresponding insulation mat.

13. The building of claim 12 wherein the top and bottom skin of each insulation mat are fabricated of polyethylene film and said insulation material is fiberglass.

14. A method of fabricating an insulated metal building comprises the steps of:
erecting a metal frame structure including a series of upright support columns and a series of angled supports;
forming a plurality of fluid-impermeable envelopes;
filling said envelopes with insulation material;

sealing said envelopes closed thereby creating a plurality of insulation mats;
applying said plurality of insulation mats over said support members;
covering said plurality of insulation mats with metal panels; and securing said metal panels to said support members by inserting fasteners through said metal panels, through said insulation mats into said support members.

15. The method of claim 14 wherein said sealing step is performed by heat sealing.

16. The method of claim 15 which further includes the step of joining adjacent insulation mats together as they are applied over said support members.