GB2194261A

GB2194261A - Heat insulating roof structure

Info

Publication number: GB2194261A
Application number: GB08620262A
Authority: GB
Inventors: Frederick Charles Coles
Original assignee: Individual
Current assignee: Individual
Priority date: 1986-08-20
Filing date: 1986-08-20
Publication date: 1988-03-02
Anticipated expiration: 2006-08-20
Also published as: GB8620262D0; GB2194261B

Abstract

A thermally insulating inner roof structure particularly intended to form a continuous heat-insulating shell with a thermally insulating wall structure, comprising spaced parallel rafters (14, 16) depending from the roof purlins (18) and thermally insulating panels (20) located between the rafters by means of composite heat-insulating sleeve member (32). The sleeve may be provided with an apertured flange (76 Fig. 2b not shown) for supporting services, and a neoprene sealing strip (70 Fig. 2b nor shown) for sealing between the sleeve and the insulating panels. <IMAGE>

Description

SPECIFICATION Heat insulating roof structure This invention relates to a heat insulating roof structure for a building, more especially a commercial, industrial, leisure or like building.

For industrial and like buildings, various heat insulating roof structures are already known, including inter-purlin heat insulating structures in which the inner ends of the purlins are shielded to prevent heat loss by cold bridging through the purlin from the warm building interior to the cold roof space below the outer roof. An object of this invention is to provide an under-purlin heat insulating inner roof structure whereby very high standards of heat insulation can be achieved.

The inner roof structure according to the invention comprises spaced, parallel steel rafters dependent from the roof purlins, each rafter having a principal web extending normally to the plane of the roof and at its inner lower end a transverse web which extends parallel to the plane of the roof on both sides of the principal web; composite heat insulating inner roof panels each extending the full width between adjacent rafters, each panel having a relatively thick heat insulating layer and a relatively thin lining layer on its under side; and a composite sleeve member located around the transverse web of each column, each sleeve member having a heat insulating inner element and an outer lining element, the inner roof panels being located each with the end regions of its lining layer seated against the sleeve members located around the transverse inner webs of adjacent rafters, thereby thermally to isolate the steel rafters which connect with the roof purlins from the inner building space.

The invention thus provides an inter-rafter heat insulating roof structure wherein cold bridging, i.e. heat loss through the rafters to the cold upper air space, is substantially eliminated.

The heat insulating inner roof structure of this invention is preferably employed in conjunction with a heat insulating wall structure with which it forms a continuous heat insulating building shell. A heat insulating building wall structure suitable for use in combination with the present invention is defined and described in my copending patent Application No.

The steel rafters preferably employed in this invention include or comprise main rafters in the form of I-beams, or lattice-type rafters which may include inturned flanges at the ends of their transverse inner and/or outer webs. The thickness of the inner roof panels may be less than the distance between the lower and upper transverse webs of these main rafters, and packers may be provided beneath the upper transverse webs to urge the panels downwardly into tight engagement with the sleeves around the lower transverse webs, possibly via a neoprene vapour check strip. Optionally, the roof structure may include auxiliary T-section rafters intermediate the main rafters.The end regions of the roof panels may simply seat under gravity against the sleeves surrounding the transverse webs of these intermediate rafters, or alternatively compression clips or the like may be employed at the upper ends of the principal webs of these rafters. Compression clips, or gravity, may also be relied on at the main rafters in order to seat the roof panels against the sleeves.

One possible sleeve member is of a wide Ushape, with inturned flanges at the upper ends of its side limbs. The outer lining element of the sleeve member may be of metal or of plastics material. It is alternatively possible to employ somewhat similar sleeve members but with out-turned flanges. These will preferably be used in conjunction with heat insulating packers fitted in the space which would otherwise be occupied by the inturned flanges. A possible disadvantage of the sleeve with outturned flanges is that pins or other securing means are required to fix the sleeve in position; the sleeve with inturned flanges, on the other hand, hooks around the transverse web of the rafters and is thereby self-supporting.

Another embodiment of sleeve member is of wide U-shape without either in-turned or out-turned flanges. Such a sleeve may be located in position by means of clips which have a part which locates against the transverse web of a rafter and a part which is bolted to the sleeve. The bolt may simultaneously serve to fix in position, on the underside of the sleeve; a support plate which may be equipped with flanges in turn for providing support for services such as electrical wiring.

The inner roof panels are factory fabricated and may have a lining layer on the underside of any convenient material, but preferably a plastics material, and the surface of this lining layer may be provided with any desired finish.

The panels are preferably reinforced at or adjacent their end regions, as by timber inserts located in the regions where the panels seat against the sleeve members. The panels may also incorporate fire-retardant material, e.g. as the inner layer thereof, thereby to reduce heating of the rafters with consequent risk of buckling and roof collapse.

The panels may be inserted into position between the rafters by sliding from between the rafter ends, e.g. from the roof ridge. Alternatively, one end of a panel may be inserted into one rafter at an angle, and the other end swung into position. The latter method is especially suitable when intermediate T-section rafters are employed. Both methods of assembly are preferably carried out before fixing the outer roof, conventionally in the form of corrugated sheeting held down on to the tops of the purlins by fixing hooks.

The inner roof structure in accordance with the invention is exemplified in the accompanying drawings, in which: Figure 1 shows the roof structure in transverse cross-section normal to length of the rafters; Figures 2A and 2B show modifications; Figures 3A and 3B show application of the invention with lattice-type rafters; and Figure 4 shows part of a building provided with a heat insulating continuous shell.

Although for simplicity and clarity in illustrating the invention it is not readily apparent from Figure 1, a building of the kind to which the invention is applied conventionally has a relatively low pitched gable roof. In the drawing, the left-hand end of the figure corresponds to the gable end and the partly shown vertical wall is the gable end wall.

In Figure 1, therefore, the reference 10 denotes one of the spaced parallel roof purlins.

The outer roof 12, conventionally of corrugated sheeting, is held down to the-tops of the purlins by fixing hooks (not shown), again in accordance with conventional practice.

The rafters are fixed in spaced parallel relationship beneath the purlins and, in accordance with the invention, these comprise steel rafters of a cross-section providing a principal web and a transverse lower end web extending to both sides of the principal web. As illustrated, the rafters comprise main I-beam rafters 14 and intermediate T-section rafters 16. Means whereby the rafters 14, 16 are fixed to depend from the purlins 10 are indicated at 18.

Heat insulating inner roof panels 20 form part of an interrafter heat insulating system.

These panels 20 each comprise a thick layer 22 of thermal insulating material, and a relatively thin lining layer 24, for example of plastics material, forming the undersurface.

The panels 20 are supported at their opposite end regions on the transverse webs of the rafters 14, 16, through the intermediary of heat insulating sleeve members 26 which cover said transverse webs.

Each sleeve member 26 has an outer facing 28 of metal or plastics material, which is relatively rigid, and a filler 30 of thermal insulation. Moreover, each sleeve member 20 is of a relatively wide U-shape, with inturned flanges 32 at the ends of its side limbs; whereby it slides or hooks over the transverse web of the rafter 14, 16 to which it is applied in order to be self supporting thereon. The inner roof panels 20 seat against the inturned flanges 32 of the sleeve members 26, and preferably the panels 20 are timber reinforced, for example as indicated at 34, in this region.

Packers 50 may be employed at the main rafters 14 to urge the panels 20 downwardly into tight engagement with the sleeve members 26. If desired, compression clips or the like (not shown) may be used at the T-section rafters 16.

The sleeve members 26 serve to avoid cold bridging between the warm and cold air spaces, i.e. loss of heat through the heat conducting rafters from the warm building interior 36 to the cold air space 38 below the outer roof. Effectively, the rafters 14, 16 are thermally isolated within the inter-rafter heat insulating system.

The panels 20 may be inserted endwise between the sleeved rafters, e.g. from the roof ridge, and at abutting ends may be designed to interlock if desired.

At the left-hand end of Figure 1 is shown the gable end wall 40, which is preferably constructed in accordance with the structure defined and described in my copending Patent Application No. . In conjunction with the wall structure, the heat insulating roof structure of this invention provides the building with a complete shell of thermal insulation, which may also have fire retardant properties.

This is shown more clearly in the cut-away view of Figure 4, wherein reference 52 denotes a wall structure in accordance with the aforementioned copending Patent Application, 54 is the outer roof, 56 the timber or metal purlins, 57 the edges (flanges) of RSJ type rafters, 58 the thermal and possibly fire retardant inner roof panels, and 60 the thermally insulating and possibly fire retardant sleeve members which locate around the inner edges of the rafters. The heat insulating continuous shell formed by the inter-rafter heat insulation and the heat insulating wall structure is readily apparent.

Figure 1 shows in more detail the arrangement at the top of the gable wall, where said wall has a heat insulating wall panel 42 which is partly cut away so as to accommodate the end rafter 14. Reference 44 denotes a gable end trim, also of heat insulating character.

Referring now to Figures 2A and 2B, these figures illustrate modifications using U-shaped composite sleeve members 62 which are not provided with in-turned (or outturned) flanges such as 32 in Figure 1. These sleeve members 62 are located to the transverse rafter webs 64 by the use of locating clips 66 and bolts 68. Reference 70 denotes neoprene vapour check strips. The heat insulating inner roof panels 72 seat against the sleeve members 62 (via the vapour seals 70) under the force of gravity, but compression clips or packers could be provided if preferred.

This modification enables sleeve member support plates 74 to be fixed in position by the same bolts 68, as may be preferred when the inner roof structure is of relatively heavy or substantiai construction. Figure 2B, in particular, shows a development in which the support plates 74 are formed with apertured flanges 76 which form supports for services, e.g. electrical wiring (see also Figure 4B).

Figures 3A and 3B show the use of composite sleeve members 62 analogous to those shown in Figures 2A and 2B, but employed in conjunction with lattice type rafters 78 which conventionally have in-turned flanges 80 at the ends of their transverse webs 82. In Figure 3A, the sleeve members 62, together with sleeve and/or service support plates 74, are located in position by hooked bolts 84. In Figure 3B, bolts 86 and separate locating clips 88 are illustrated. Reference 90 denotes the purlins which carry the outer roof. Reference 92 denotes an optional hold-down clip.

The above described and illustrated embodiments may be modified in various ways within the scope of the invention hereinbefore defined.

Claims

1. An inner roof structure comprising spaced, parallel steel rafters dependent from the roof purlins, each rafter having a principal web extending normally to the plane of the roof and at its inner lower end a transverse web which extends parallel to the plane of the roof on both sides of the principal web; composite heat insulating inner roof panels each extending the full width between adjacent rafters, each panel having a relatively thick heat insulating layer and a relatively thin lining layer on its under side; and a composite sleeve member located around the transverse web of each column, each sleeve member having a heat insulating inner element and an outer lining element, the inner roof panels being located each with the end regions of its lining layer seated against the sleeve members located around the transverse inner webs of adjacent rafters, thereby thermally to isolate the steel rafters which connect with the roof purlins from the inner building space.

2. A structure according to claim 1, in combination with a heat insulating wall structure with which it forms a continuous heat insulating shell.

3. A structure according to claim 1 or claim 2, employing I-beam or lattice-type main rafters having inturned flanges at the ends of their transverse inner and/or outer webs.

4. A structure according to claim 1 or claim 2 or claim 3, wherein the thickness of the inner roof panels is less than the distance between the lower and upper webs of the main rafters, and packers are provided beneath the upper transverse webs to urge the panels downwardly into engagement with the sleeve members around the lower transverse webs.

5. A structure according to claim 4, including neoprene vapour check strips incorporated between the panels and the lower transverse webs.

6. A structure according to any of claims 1 to 5, employing T-section rafters intermediate main rafters.

7. A structure according to any of claims 1 to 6, wherein the panels rest under gravity against the sleeve members on the lower transverse webs of the rafters.

8. A structure according to any of claims 1 to 6, in which the panels are urged against the sleeve members on the lower transverse webs of the rafters by means of compression clips.

9. A structure according to any of claims 1 to 8, wherein each sleeve member is of a Ushape, with inturned or outturned flanges at the free ends of its side limbs.

10. A structure according to claim 9, employing heat insulating packers to fill any space between the flanges of the sleeve members and the main webs of the rafters.

11. A structure according to any of claims 1 to 10, including clips which secure between the sleeve members and the associated transverse web of the rafter at which the sleeve member is located.

12. A structure according to claim 11, wherein the clips are fixed to the sleeve mem bersby securing means also serving to fix in position a supporting means for electrical wiring or other services.

13. A structure according to any of claims 1 to 12, having end edge reinforcement where the panels engage the sleeve members.

14. A structure according to any of claims 1 to 13, wherein the inner roof panels incorporate fire-retardant material.

15. An inner roof structure substantially as hereinbefore described with reference to the accompanying drawings.