GB1590450A

GB1590450A - Insulation system for building structures

Info

Publication number: GB1590450A
Application number: GB2309177A
Authority: GB
Original assignee: Johns Manville Corp; Johns Manville
Current assignee: Johns Manville Corp; Johns Manville
Priority date: 1976-06-01
Filing date: 1977-06-01
Publication date: 1981-06-03
Also published as: CA1068868A; AU508089B2; FR2353685A1; FR2353685B1; AU2568377A

Description

(54) INSULATION SYSTEM FOR BUILDING STRUCTURES (71) We, JOHNs-MANvILLE CORPO RATION, a corporation organized under the laws of the State of New York, United States of America, having a place of business at Ken-Caryl Ranch, Jefferson County, Colorado, mailing address P.O. Box 5723, Denver, Colorado 80217, United States of America, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The present invention relates to an insulation system that is easy to install and that thermally isolates most or all of the structural members of a building frorn the interior of the building as well as from the exterior covering of the building.

In the past, building structures such as metal buildings or buildings made from concrete structural members, or buildings made using combinations of concrete and metal structural members have been insulated in many ways. For example, fiber glass blanket insulation has been put between the structural members and held in place with such things as metal straps, chicken wire, etc.

Rigid or semi-rigid boards of felted fibers such as glass fibers, have also been used for insulating metal and concrete buildings, but no attempt was made to isolate the structural members from the interior of the building and such rigid of semi-rigid boards did not provide sufficient insulation to meet the newly emerging standards.

Another insulating system used extensively, particularly in metal buildings, is shown in FIG. 1 and is described in detail in U.S. Patent No. 3 979 537. This insulation product, known in the trade as RIGID ROLL, comprises a layer of bonded glass fibers A which is flexible but yet board-like in that it tends to return to a board-like product after being bent and released. The layer of bonded glass fibers is faced with a vapor barrier B, such as a vinyl film. The facing, along a longitudinal edge, extends beyond the layer of bonded glass fibers to form a tab (not shown). The tab is reinforced so that when the strips of RIGID ROLL are butted together and the tab overlies an adjacent strip, the tab forms a vapor barrier seal between adjacent strips of insulation when the metal roof sheets C are mounted in place over structural members such as D.

While such an insulation system is easy to install and offers many advantages over other systems, compression of the fibrous layer between the outer sheets C and the structural members D seriously reduces the insulating value of the insulation at those areas. As a result, such a system alone will not meet some of the high insulating standards required either by specifications or by economics in many areas of the country.

Another insulation system, which does meet high insulating standards and which may be used in metal buildings is described in U.S. Patent No. 4 014 150. This system shows as in FIG. 2 a first thermal insulation A located between the structural members and the roof covering material 6, a secondboard-like thermal insulation 8 spanning between adjacent structural members, a third thermal insulation 12 having a higher insulating value than the second thermal insulation and located between the second insulation and the covering material, and a fourth insulation means 14 which serves to isolate the support members from the interior of the building and to support the second thermal insulation 8 on either side of a web 3 of support members 2.The chief drawback of this insulation system lies in the fact that in the installation of the system the fourth insulation means 14 must be secured to the support member in the conventional time consuming manner by metal screws, rivets, bolts, etc. -. Also the ease and simplicity of this method is hampered by the fact that the interior ceiling layer of insulation comprises more than one insulation means; for example the board-like insulation 8 and the insulation means 14.

The object of the present invention is to provide an attractive insulating system which can be easily and rapidly installed either in new construction or in the re insulation of old construction, that can be used either alone or in conjunction with prior art insulation systems of the type shown in Figure 1, and that will provide a more efficient insulation system for the types of buildings described above by insulating and isolating all or most of the structural members of the building from the interior of the building, as well as from the exterior covering of this building.

Accordingly, the present invention provides an insulation system for building structures having a plurality of parallel structural members and a covering material spanning the structural members on the exterior side, both the structural members and the covering material having a relatively high coefficient of thermal conductivity.The system comprises first board-like thermal insulation elements for isolating the structural members from the interior of the building, each of said first insulation elements being supported along a first edge portion proximate a lower portion of a first structural member, said first insulation element spanning from proximate the lower portion of said first structural member to an adjacent second structural member, said first insulation element having a second edge portion extending beneath said second structural member, a second thermal insulation element substantially filling the spaces between said structural members and between said covering material and said first insulation element, said second insulation element having a lower density and a higher thermal insulation value than said first insulation, means for urging said second edge portion of said first insulation element into contact with the lower portion of said second structural member and means for providing a support for a first edge portion of an adjacent first insulation element, said urging means and said supporting means being supported by said second structural member only on one side of said second structural member.

FIG. 1 is a fragmentary view, partly in perspective and partly in section of a typical prior art insulation system including some of the structural members and the covering materials, and illustrating a known technique for isolating the covering materials from the structural members.

FIG. 2 is a fragmentary view partly in section and partly in perspective of an insulation system according to the present invention.

FIG. 3 is a fragmentary cross-sectional view of a second embodiment of an insulation system according to the present invention.

FIG. 4 is a cross-sectional view of a mounting clip used in the embodiment shown in FIG. 3.

FIG. 5 is a fragmentary view similar to FIG. 2 of a third embodiment of the insulation system according to the present invention.

FIG. 6 is a fragmentary cross-sectional view of a joint made between insulation boards.

FIG. 7 is a view similar to FIG. 6 of a different type of joint.

FIG. 8 is a fragmentary view in elevation showing how a joint member shown in FIG.

7 is supported.

FIG. 9 is a view similar to FIGS. 2 and 5 of an alternative embodiment of an insulation system according to the present invention.

FIG. 10 is a fragmentary cross-sectional view showing an alternative technique for isolating the covering material from the structural members.

FIG. 11 is a cross-sectional view of a mounting clip used in the embodiment shown in FIG. 9.

Commercial and industrial buildings are frequently of the type shown in U.S. Patent No. 3,121,649 and comprise metal or concrete structures with an outer covering of a material, such as corrugated metal, concrete panels, etc., spanning the structure. Both metal and concrete have a relatively high coefficient of thermal conductivity compared to wood and thermal insulating materials and therefore it usually is desirable, and sometimes essential, that these buildings be insulated with a material having a relatively low coefficient of thermal conductivity to reduce the rate of heat flow either into or out of the building. A coefficient of thermal conductivity of about 1. 5 BTU/sq.ft./in./"F/hr. or less is a relatively low coefficient of thermal conductivity for purposes of defining the terminology herein.

Since the structural members themselves provide paths for substantial heat flow through the walls, insulation systems which do not insulate all or most of the structural members from the interior of the building, and preferably from the covering spanning the structural members of the exterior side of the structural members, permit excessive heat flow through the structural members.

Referring to FIG. 2, one aspect of the present invention insulates and isolates structural members 2, which are illustrated as "S" shaped purlins spanning between conventional supports (not shown). The insulation system of the present invention comprises first board-like insulation means 4 which spans the purlins 2 on the interior of the structure. A covering material such as a corrugated metal sheet 6 forms the exterior layer on the structure.The first insulation 4 may be strips of glass of fiber blankets or boards, strips of foamed plastic material, or any other material having a relatively low coefficient of thermal conductivity, com pated with the coefficient of thermal conductivity of the structural members and of the covering material 6, and having sufficient strength and rigidity to resist significant sagging, say not more than about 1" bow or sag between adjacent purlins which often are spaced about 5' apart. Preferably, no more than 1/2" sag is experienced. A preferable material for the first insulation 4 in the present invention is a board of bonded glass fibers having an apparent density of about 1.75 to 2.5 Ibs./cu.ft. or more, most preferably about 3pcf or more.

In the embodiment of FIG. 2, each of the strips constituting the first insulation means 4 overlies and is supported along one of its edge portions 10 by an adjacent first insulation means 4 and spans to and extends beneath an adjacent structural member 2.

Each of the first insulation means 4 has a second edge portion 12 in which a depression 14 is formed for accommodating a bottom flange 2a of a purlin 2. The depression 14 is sufficiently deep so that when the bottom surface of the flange 2a is in contact with the bottom of the depression 14 an edge rib 15 of the second edge portion 12 extends above the upper surface of the flange 2a to provide support for the first edge portion 10 of an adjacent first insulation 4. The depression 14 can be cut or pressed into a fiber glass board, either being done in a well known manner.

Preferably, a major surface 18 of the first insulation 4 opposite the surface having the depression 14 is coated or faced with a material that will constitute a vapor barrier, such as a vinyl film. This coating or facing 19 also can provide a pleasing appearance to the interior of the building. The facing or coating 19 should extend around and over an exposed edge 20 of the second edge portion 12 and the rib 15, so as to provide a better vapor seal between the overlapped portions of the adjacent boards of the first insulation 4. To enhance the vapor seal, if preferred, a caulking of sealing material can be applied to the rib 15 prior to installing the adjacent first insulation board 4.

In a preferred embodiment of this aspect of the present invention, the first insulation 4 is a vinyl faced, glass fiber insulation board about 1.25 inches thick and having an insulation value or thermal resistance (R, of about 5. The R value of an insulation material, which value expresses the material's ability to resist the transfer of heat, may be determined by the ASTM method C236-66, known as the guarded hot box method.

Any suitable fastening means can be used to hold the first insulation 4 against the flanges 2a. In the embodiment shown in FIG. 2, rivets 22 are used with plastics washers 24, e.g., polyethylene or nylon washers can be used.

A second insulation 8 is positioned above the first insulation 4 and between adjacent purlins 2. Any suitable insulating material having a high insulating value is suitable as the second insulation, e.g., blankets or clumps of glass fibers or mineral wool or equivalents. For ease of installation, it is preferred to use butts or continuous strips of bonded glass fibers or mineral wool having an R-value of R-5 or above, preferably R-19 or above, and most preferably an insulating value of about R-30 or higher.

A third insulation A, which is often an embodiment of the prior art insulation of the type shown in FIG. 1, is provided between the top of the purlin 2 and the covering material 6 to isolate purlins 2 from the covering material 6. This third insulation A completes the isolation of the purlins 2 and minimizes heat transfer from those structural members to the covering material 6, thereby also minimizing moisture condensation problems. When the third insulation is in the form of the insulation A shown in FIG. 2, which occurs particularly when an insulation system according to the invention is used to reinsulate a building structure having prior art insulation of the type shown in FIG. 1, the added second insulation 8 can be thinner because the insulation A of the prior art system cooperates therewith.In some instances, such as when the covering material is always on the hot side of the structure, it is acceptable to have the structural members or purlins 2 in direct contact with the covering material.

FIG. 3 illustrates a modification of the insulation system shown in FIG. 2. In this modification, the second edge portion 12 of the first insulation 4 is fastened to the flange 2a in the depression 14 using an elongated clip 26 that extends along the edge of the first insulation means 4. A bottom portion 28 of the clip 26 supports the bottom face of the second edge portion 12 and extends away from the edge portion 12 past a vertical web 30 of the purlin 2 preferably about an inch or more. An upper portion 32 of the clip 26 supports the first edge portion 10 of the adjacent first insulation means 4.

The longer leg 28 of the clip 26 is designed to support the ends of transversely extending "H" or "T" bars, or the like, between longitudinally adjacent edges of the first insulation means 4 as more fully described below with reference to FIGS.

6-8, inclusive.

As shown in FIG. 4, the clip 26 comprises the longer leg 28, the upper leg 32 which has and edge 34 offset by a web 36 toward the leg 28, the legs 28 and 32 being connected by a web 38 which is wider than the web 36.

As best can be seen in FIG. 3, the clip 26 is openend from its normal configuration and slipped over the rib 16 to embrace the flange 2a and the edge portion 12 of a first insulation board 4 to retain the board 4 firmly in place. The clip 26 can be made of any material having sufficient resilience so that its legs 28 and 32 can be separated to allow for its installation and still try to return to its original configuration with sufficient force to hold the first insulation 4 in its proper position. A preferred material is rigid polyvinyl chloride, preferably having the same or similar color as the facing 19.

One significant advantage of the modification shown in FIG. 3 over the embodiment shown in FIG. 2 is that the insulation system of FIG. 3 can be more easily installed from the exterior sides of the structural members 2, i.e. on top of the roof, than can the embodiment of FIG. 2. This is often important, particularly when reinsulating an existing structure where equipment and other objects permanently in the building would hamper the erection of scaffolds for working below the rafters 2, or in high roofed buildings where it is easier to work from the roof than to erect tall scaffolds that have to be moved frequently during construction. The clip 26 as used in the modification shown in FIG. 3 also provides a continuous support for the first insulation 4 as opposed to the periodic support provided by the fastening means 22 and 24 used in the embodiment shown in FIG. 2.

FIG. 5 illustrates another embodiment of the present invention. This embodiment differs from the embodiment shown in FIG. 3 in that the first insulation 4 does not have a depression. This modification requires that a web 38a of a clip 26 be wider than the web 38 of the clip 26 used in the embodiment shown in FIG. 3. Also, the first insulation 4 lies at a slightly greater angle with respect to the flange 2a of the purlin 2 in this embodiment than in the embodiment shown in FIG.

3. The two important advantages of the embodiment shown in FIG. 5 over the embodiment shown in FIG. 3 are that (1) the purlin 2 is better isolated thermally from the interior of the building due to the fact that the insulation boards 4 do not need a depression like the depression 14 shown in FIG. 3, and (2) the added expense of forming the depression 14 is avoided. An open region 40 resulting from the wider web 38a in this embodiment if desired can be filled with a strip of any suitable insulating material to even further insulate the purlin 2 from the interior of the building. A foaming type insulation also could be injected into the open region 40 after installation.

In the embodiment shown in FIG. 5, the clip 26 is so designed that when in the installed position, the leg 28 fits against the faced surface 18 of the first insulation 4 and the second shorter leg 34 fits against the upper surface of the flange 2a of the purlin 2. In this position, the upper leg 32 of the clip 26 will support the first edge portion 10 of an adjacent first insulation board 4.

Frequently, the structural members 2 are longer than the first insulation boards 4.

When this occurs it is necessary to use more than one board or strip of the first insulation means 4 resulting in a joint between two longitudinally adjacent boards.

FIGS. 6-8 show several suitable methods of providing a vapor barrier seal and support at these joints. In FIG. 6, with either of the embodiments shown in FIGS. 2, 3 or 5, an H-shaped member 42 can be used to provide a vapor barrier at the joint between two adjacent panels 4. The H-shaped member 42 is preferably made of a metal or a plastics material such as a rigid polyvinyl chloride, and at least that portion exposed to the interior of the building is preferably of the same color as the facing 19. A good seal is insured if the combination of the thickness of the insulation board 4 and the facing 19 is slightly thicker than the spaces between the parallel arms of the H-shaped member 42 so that the first insulation boards 4 must be slightly compressed in order to insert them therebetween.When used in the embodiment shown in FIG. 5, the length of the H-shaped member 42 should be the same as the width of the first insulation board 4. In the embodiment shown in FIG. 3 the member 42 will rest on that portion of the leg 28 of the clip 26 extending beyond the web 30 of the purlin 2.

FIG. 7 is a cross-section taken from the same position as FIG. 6 and illustrates the use of a T-shaped member 44 filling the joint between two longitudinally adjacent pieces of the first insulation 4. It can be noted that one end of the T-shaped member 44 rests on an upper surface of the long leg 28 of the clip 26. When used with the embodiment shown in FIG. 5, one end of the T-shaped member 44 can extend completely under the flange 2a of the purlin 2, as shown in FIG. 8.

Preferably, cross bars 46 of the T-shaped members 44 that would rest on the legs 28 and 32 of the clips 26 are removed, as shown in the righthand portion of FIG. 8, to provide a better vapor seal between the first insulation boards 4 and the legs 28 and 32.

Removing those portions of the cross bars 46 aligns the top surface 48 of the bottom member 46 with the upper surfaces of the legs 28, 32, thus eliminating the small gaps 50 shown in FIG. 7.

FIG. 9 illustrates another preferred embodiment of the present invention in which the first insulation means 4 are supported so as to provide a flat ceiling. This modification provides a clip 52 that extends along the edge of the first insulation means 4 similar to clip 26.

As shown in FIG. 11, the clip 52 comprises a long bottom leg 54, an upper leg 56, which has an edge 58 offset by a web 60 toward the leg 54, the legs 54 and 56 being connected by a web 62. The bottom leg 54 has an integral portion 64 extending past the juncture of the leg 54 and the web 62.

Like the clip 26, each clip 52 is fabricated from resilient material so that its legs 54 and 56 together with edge 58 can be moved away from each other and the clip can be slid into embracing relationship to an edge portion 10 of a first insulation means 4 and a flange 2a of a purlin 2 and the edge 12 of the adjacent insulation means 4 is supported by the extending portion 64 as shown in FIG.

9.

In all of the embodiments shown, it is preferred that the second insulation 8 be of sufficient thickness that it must be compressed somewhat when the first insulation 4 is put into the positions shown in the drawings.

When compressed, the second insulation 8 applies a small downward force against the first insulation improving the vapor barrier seal between the facing 19 of the first insulation means 4 and the various supports. Better vapor barriers are desirable, of course, because the structural members may be either significantly cooler or warmer than the interior of the building. If warm air from the interior of the building is permitted to flow up around the structural members, the cooler structural members will cool this warmer air leaving water condensation on the structural members. Such a result is undesirable and can damage both the structural members and the insulation system.

Adhesives, sealing compounds, or pressure sensitive tapes can be used in the vapor sealing areas previously described, but this is usually not necessary in the system of the present invention and therefore would, in most cases, needlessly add to the cost of the installation.

When the insulation system of the present invention is used along with a prior art insulation system, such as that shown in FIG. 1, the structural members 2 are isolated by the prior art insulation system from the covering material 6. When the third insulation A has a vapor barrier layer B on its lower or interior face, the barrier layer can be punctured periodically to prevent trapping moisture between the second insulation 8 and the barrier layer facing on layer A.

As shown in FIG. 10, the third insulation means for isolating the covering material 6 from the structural members 2 may be a strip of material 66, having a relatively low coefficient of thermal conductivity as compared with the covering material 6 and the purlins 2. For example, the insulation material 52 can be strips of glass fiber blanket or board, strips of foamed plastic material, strips of wood, or any other material having a relatively low coefficient of thermal conductivity.

WHAT WE CLAIM IS: 1. An insulation system for building structures having a plurality of parallel structural members and a covering material spanning the structural members on the exterior side, both the structural members and the covering material having a relatively high coefficient of thermal conductivity, said system comprising: first board-like thermal insulation elements for isolating the structural members from the interior of the building, each of said first insulation elements being supported along a first edge portion proximate a lower portion of a first structural member, said first insulation element spanning from proximate the lower portion of said first structural member to an adjacent second structural member, said first insulation element having a second edge portion extending beneath said second structural member, a second thermal insulation element substantially filling the spaces between said structural members and between said covering material and said first insulation element, said second insulation element having a lower density and a higher thermal insulation value than said first insulation, means for urging said second edge portion of said first insulation element into contact with the lower portion of said second structural member and means for providing a support for a first edge portion of an adjacent first insulation element, said urging means and said supporting means being supported by said second structural member only on one side of said second structural member.

2. An insulation system as defined in Claim 1 wherein said urging and supporting means comprises clip means for urging the second edge portion of said first insulation means into contact with said structural member, a portion of said clip means providing a support for a first edge portion of an adjacent first insulation means, said clip means extending from a major surface on said first insulation means opposite said structural member, around a minor surface of said second edge portion and onto an upper surface of the lower portion of said structural member.

3. An insulation system as defined in Claim 2 including a third thermal insulation positioned between said structural members and said covering material.

4. An insulation system as defined in Claim 2 wherein said second edge portion of said first insulation contains a depression means for accommodating the lower portion of said structural member and wherein said clip means holds said second edge portion of

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **.

4 similar to clip 26.

As shown in FIG. 11, the clip 52 comprises a long bottom leg 54, an upper leg 56, which has an edge 58 offset by a web 60 toward the leg 54, the legs 54 and 56 being connected by a web 62. The bottom leg 54 has an integral portion 64 extending past the juncture of the leg 54 and the web 62.

Like the clip 26, each clip 52 is fabricated from resilient material so that its legs 54 and 56 together with edge 58 can be moved away from each other and the clip can be slid into embracing relationship to an edge portion 10 of a first insulation means 4 and a flange 2a of a purlin 2 and the edge 12 of the adjacent insulation means 4 is supported by the extending portion 64 as shown in FIG.

9.

In all of the embodiments shown, it is preferred that the second insulation 8 be of sufficient thickness that it must be compressed somewhat when the first insulation 4 is put into the positions shown in the drawings.

When compressed, the second insulation 8 applies a small downward force against the first insulation improving the vapor barrier seal between the facing 19 of the first insulation means 4 and the various supports. Better vapor barriers are desirable, of course, because the structural members may be either significantly cooler or warmer than the interior of the building. If warm air from the interior of the building is permitted to flow up around the structural members, the cooler structural members will cool this warmer air leaving water condensation on the structural members. Such a result is undesirable and can damage both the structural members and the insulation system.

Adhesives, sealing compounds, or pressure sensitive tapes can be used in the vapor sealing areas previously described, but this is usually not necessary in the system of the present invention and therefore would, in most cases, needlessly add to the cost of the installation.

When the insulation system of the present invention is used along with a prior art insulation system, such as that shown in FIG. 1, the structural members 2 are isolated by the prior art insulation system from the covering material 6. When the third insulation A has a vapor barrier layer B on its lower or interior face, the barrier layer can be punctured periodically to prevent trapping moisture between the second insulation 8 and the barrier layer facing on layer A.

As shown in FIG. 10, the third insulation means for isolating the covering material 6 from the structural members 2 may be a strip of material 66, having a relatively low coefficient of thermal conductivity as compared with the covering material 6 and the purlins 2. For example, the insulation material 52 can be strips of glass fiber blanket or board, strips of foamed plastic material, strips of wood, or any other material having a relatively low coefficient of thermal conductivity.

WHAT WE CLAIM IS: 1. An insulation system for building structures having a plurality of parallel structural members and a covering material spanning the structural members on the exterior side, both the structural members and the covering material having a relatively high coefficient of thermal conductivity, said system comprising: first board-like thermal insulation elements for isolating the structural members from the interior of the building, each of said first insulation elements being supported along a first edge portion proximate a lower portion of a first structural member, said first insulation element spanning from proximate the lower portion of said first structural member to an adjacent second structural member, said first insulation element having a second edge portion extending beneath said second structural member, a second thermal insulation element substantially filling the spaces between said structural members and between said covering material and said first insulation element, said second insulation element having a lower density and a higher thermal insulation value than said first insulation, means for urging said second edge portion of said first insulation element into contact with the lower portion of said second structural member and means for providing a support for a first edge portion of an adjacent first insulation element, said urging means and said supporting means being supported by said second structural member only on one side of said second structural member.
2. An insulation system as defined in Claim 1 wherein said urging and supporting means comprises clip means for urging the second edge portion of said first insulation means into contact with said structural member, a portion of said clip means providing a support for a first edge portion of an adjacent first insulation means, said clip means extending from a major surface on said first insulation means opposite said structural member, around a minor surface of said second edge portion and onto an upper surface of the lower portion of said structural member.
3. An insulation system as defined in Claim 2 including a third thermal insulation positioned between said structural members and said covering material.
4. An insulation system as defined in Claim 2 wherein said second edge portion of said first insulation contains a depression means for accommodating the lower portion of said structural member and wherein said clip means holds said second edge portion of

said first insulation such that the lower portion of said structural member resides in said depression means.
5. An insulation system as defined in Claim 2 wherein said clip means comprises a long leg and a short leg and an upper support portion connected to the short leg by a first web and connected to the long leg by a second web, said second web being longer than said first web. said short leg forming an angle with said long leg when said clip is in a relaxed condition.
6. An insulation system as defined in Claim 2 wherein said first insulation is supported along a first edge portion above a second edge portion of an adjacent first insulation and a portion of a first structural member, said second edge portion having a depression means therein in a major surface for accommodating a bottom of a structural member, and wherein said clip means holds said second edge portion onto said structural member such that a portion of said structural member occupies said depression means.
7. An insulation system as defined in Claim 6 including a third thermal insulation positioned between said structural members and said covering material.
8. An insulation system as defined in Claim 6 wherein said clip means comprises an upper leg and a lower leg and an upper support portion connected to said upper leg by a first web and connected to said lower leg by a second web, said second web being longer than said first web, said upper leg forming an angle with said lower leg when said clip is in a relaxed condition.
9. An insulation system as defined in Claim 2 wherein said clip means supports the adjacent edge portions of two of said first insulation elements in generally the same plane and wherein said clip means extends from an upper surface of the lower portions of said structural members, around the edges thereof, between minor surfaces of adjacent first insulation elements, and beneath a portion of the lower major surfaces of said adjacent first insulation elements.
10. An insulation system as defined in Claim 9 wherein the clip means comprises a long bottom leg and a shorter opposed bottom leg which are substantially in the same plane, and a top leg extending over and spaced from said long bottom leg, said top leg being connected by a web to the line of intersection of said long and shorter bottom legs, said top leg forming an acute angle with said long leg when said hanger is in a relaxed condition.
11. An insulation system substantially as hereinbefore described with reference, and as shown in, any one of the embodiments illustrated in Figures 2 to 11 of the accompanying drawings.