EP0270218A2

EP0270218A2 - Roof structure in or for a building module

Info

Publication number: EP0270218A2
Application number: EP87308843A
Authority: EP
Inventors: Stephen Wentworth Stericker; Peter Mansell Roberts; Martin Goss
Original assignee: Portakabin Ltd
Current assignee: Portakabin Ltd
Priority date: 1986-10-07
Filing date: 1987-10-06
Publication date: 1988-06-08
Also published as: GB2196661B; EP0270218B1; GB2196661A; GB8624017D0; GB8723392D0; DE3777561D1; EP0270218A3

Abstract

The structure comprises a pair of spaced parallel roof beams (16) interconnected solely by one or more roof panels, the or each roof panel comprising an insulated structural sandwich having inner and outer skins (41, 42) and having therebetween an insulating infill and at least one transverse reinforcing member (51) disposed intermediate the ends of the panel.

Description

Description of Invention

This invention relates to a roof structure in or for a building module, which may be assembled with further similar modules, to provide a modular building construction. Each module is factory assembled for delivery to a prepared site in an assembled condition complete with at least a roof.
More particularly, the or each module comprises a structural metal frame to which roof and preferably, floor structures are attached. Where such modules are to be assembled together to form a modular building construction, the structural frames are connected together in the desired arrangement.
In the factory or on-site end walls and side walls are secured to the frame, one or more of such end or side walls being omitted if required, to permit full width linking or end-to-end linking of two or more of the modules.
Such building modules will hereinafter be described as "of the type described".
An object of the invention is to provide a new and improved roof structure in or for a building module of the type described.
According to one aspect of the present invention, we provide a roof structure, for a building module, comprising a pair of spaced parallel roof beams interconnected solely by one or more roof panels, the or each roof panel comprising an insulated structural sandwich having inner and outer skins and having therebetween an insulating infill and at least one transverse reinforcing member disposed intermediate the ends of the panel.
By "transverse reinforcing member" we mean a reinforcing member which strengthens the roof panel in a direction perpendicular to the roof beams.
The or each panel may comprise a pair of spaced slide members and the or each reinforcing member may extend between and be connected to the side members.
The or each panel may comprise a pair of spaced parallel end members.
Each side member and/or each transverse reinforcing member may be connected to an associated roof beam preferably by a fastener engaged with the side member and/or each transverse reinforcing member and with the associated roof beam.
The inner skin may comprise a steel sheet and the steel sheet may be provided with a suitable surface finish, such as a coloured plastic coating.
The outer skin may comprise a steel sheet and the steel sheet may be provided with a suitable surface finish, such as a coloured plastic coating.
The infilling may comprise foam plastics material such as polyurethane foam.
The inner and outer skins and infilling may be bonded together.
The or each transverse reinforcing member preferably comprises a steel section and the section is preferably a channel section with the web of the channel extending generally perpendicular to and between the inner and outer skins and one limb of the channel extending generally parallel to and adjacent the outer skin and being of greater length than the other limb, which is disposed closer to the inner skin and generally parallel thereto.
The one limb may have an inturned flange at its free end.
The one limb may project lengthwise of the reinforcing member beyond the web and overlie a portion of the side member at each end of the reinforcing member.
The projecting portion of the limb may be fastened to the associated side member and/or the associated roof beam.
The or each panel may also comprise at least one transverse divider to divide the or each panel into a plurality of sections, each of which is filled with said infilling during manufacture.
A divider may be provided adjacent each transverse reinforcing member.
The or each divider may comprise a base part of relatively rigid material such as plywood and a top part, which may be of less rigid material such as polyurethane foam, of a configuration to conform with the configuration of the internal surface of the outer skin.
The or each panel may comprise a plurality of discrete spacer blocks disposed between the inner and outer skins to maintain the skins in spaced relationship during manufacture and in particular during filling with the insulating infill material.
The or each roof panel may be secured to the roof beams so as to be disposed below the roof beams.
The or each roof panel may be secured to the roof beams so as to be disposed below the roof beams at a distance which increases from one end of the roof structure to the other.
To provide said variation in distance, spacer members may be provided between the roof beams and the/or each roof panel the spacer members being of increasing height from said one end of the roof structure towards the other.
The reinforcing member, the inner skin and the side members of the or each roof panel are preferably all directly connected to the roof beams, for example by bolts or other suitable fasteners, to ensure structural continuity but with the provision of spacer members, as appropriate, to provide the roof panels with a desired slope.
Preferably, insulating infilling is provided between the inner skin and the reinforcing member and may be, additionally, provided between the outer skin and the reinforcing member. The provision of insulating infilling between the reinforcing member and the inner skin eliminates "cold bridging" through the reinforcing member from the exterior of the roof to the interior of the module.
The hereinbefore mentioned bonding of the infilling to the inner and outer skins ensures good structural continuity of the roof panels.
Any tendency to sag in the roof beams may be compensated for by providing spacer members of appropriate length to eliminate any downward deflection of the or each roof panel.
The slope of the roof panels may lie in the range 1 in 120 to 1 in 60.
According to another aspect of the invention, we provide a building module comprising a structural metal frame comprising a pair of lateral vertical sub-frames, each of said sub-frames including an upper member and a lower member, the upper and lower members of each sub-frame being interconnected by uprights, and the lower members of the sub-frames being rigidly interconnected in spaced apart parallel relation by frame cross members which extend between the lower members, and the upper members of the sub-frames comprising said spaced parallel roof beams of a roof structure according to the first aspect of the invention.
A floor structure may extend between and be supported by the lower members of said sub-frames.
Where the or each roof panel extends between and is secured to the roof beam therebelow, the roof beams are wholly external to the habitable voume of the module.
It has been found that the roof or panels provide sufficient strength to hold the sub-frames rigidly apart at their upper ends by virtue of the provision of the reinforcing members. For example, where the reinforcing members are of the channel configuration described hereinbefore, then when a load is applied to the roof deck, for example a snow load, the relatively long one limb of the reinforcing member resists the compressive forces imposed upon the panel whilest the other limb, together with the inner skin, which is preferably made of steel, resists tensile forces. Because of the relatively long one limb, the outer skin is not called upon to contribute to resist the compressive forces and thus the outer skin may be made of any desired material without regard to its ability to resist compressive forces. This permits of the use of a plastic coated steel sheet provided with corrugations in the longitudinal direction, which skin has little ability to resist compressive forces in the transverse direction of the roof structure.
Said sub-frames may define an open side or sides of the module whereby two or more similar modules may be jointed together in side-by-side relation with full width linking, but one or more side wall panels may be secured to the frame so as to provide a module with walls at one or both sides. Alternatively, or additionally, two or more modules may be connected in end-to-end relation if required.
Preferably, the or each side wall panel is secured to the outside of the associated vertical sub-frame so that the members which comprise the associated sub-frame are inside the side walls, and the or each end of the unit may be closed by one or more end wall panels. The or each end wall panel may be received substantially entirely within an end opening defined between the sub-frames so that the members which make up the sub-frames lie peripherally of the end wall panel and wholly external to the habitable volume of the module.
Conveniently, the or each end wall panel may be secured directly to the upright members of said sub-frames.
Desirably, lateral marginal portions of the roof panel and floor structure extend into the end and/or side openings defined by said sub-frames.
The end and/or side wall panels may comprise a structural sandwich comprising an outer metal skin and an inner skin sandwiching therebetween an isulating infilling. The outer metal sheet may comprise steel which may be plastics coated and the infilling may be bonded to the outer skin and may be a rigid foam or expanded plastics material.
The or each end and/or side wall panel may comprise a timber framework to which the inner and outer skins are secured.
The inner skin may comprise hardboard or plasterboard or other suitable material.
The floor structure may comprise a decking supported by a plurality of cross members which extend between and are carried by the lower members of the sub-frames, with thermal insulation below such cross members, such as a foil-faced thermal layer or other similar material fastened to the underside of the cross members. Preferably, the decking, which may be of wood particle board or the like, extends across the upper faces of the lower members of the sub-frames, whilst the cross members extend between and are secured to the inner faces of such lower members.
Conveniently, the lower members and the upper members of the sub-frames each comprise channel section steel beams arranged with the webs thereof extending vertically and the limbs extending horizontally with the open mouth of the channel facing inwardly of the module, although other types of beams may alternatively be utilised.
The upright members of each sub-frame are preferably connected to the ends of the upper and lower members of the sub-frames. Such upright members may comprise channel or hollow section steel columns although again, other constructions are possible.
The ends of the upper and lower members may be each butted against a column and secured to the column in any suitable manner, for example, by means of an angle bracket welded or bolted to the web of the upper or lower member as appropriate and bolted to the inner flange of the channel or hollow section column.
Lifting attachments may be secured to the upper members or uprights of each sub-frame, preferably at a position immediately adjacent to the joint between the respective column and upper member.
The cross members may each comprise a channel section beam, preferably arranged with the web thereof extending vertically and the limbs directed horizontally and each limb having an inwardly directed end flange.
It will be observed that where two units are connected in side-by-side relationship, the floor, roof and end wall structures of the unit are disposed entirely within the metal frame, so that the interior of the unit is free substantially from inwardly protruding beams, and thus aleviating "cold bridging" which otherwise establishes a heat loss path between the interior of the unit and the metal frame through these structures.
The invention will now be described by way of example, with reference to the accompanying drawings, wherein:-

FIGURE 1 is a partial transverse cross-sectional view in a vertical plane through a building module embodying the invention;
FIGURES 2a and 2b are partial longitudinal sections, in a vertical plane through the module of Figure 1;
FIGURE 3 is a partial transverse cross-sectional view in a vertical plane through the module of Figure 1 and illustrating the manner in which two adjoining modules are secured together;
FIGURE 4 is a plan view of a roof panel of the module of Figure 1 with part of the outer skin omitted;
FIGURE 5 is a fragmentary, broken away, perspective veiw illustrating the connection between a roof panel and a roof beam of the module of Figure 1;
FIGURE 6 is a section on the line 6-6 of Figure 4;
FIGURE 7 is a section on the line 7-7 of Figure 4; and
FIGURE 8 is a perspective view of a rigid metal frame of the building module of Figure 1.

Referring to the drawings, a building module in accordance with the invention comprises a rigid frame 10 as shown in Figure 8, preferably constructed from steel beams. The frame 10 comprises two vertical subframes 11a, 11b, each comprising respective horizontal roof beams 12a, 12b and lower horizontal floor beams 13a, 13b interconnected at their ends by uprights 14a, 14b. The two vertical sub-frames 11a, 11b are connected together by a plurality of floor joists 15, of which two extend between the floor beams 13a, 13b at positions adjacent but spaced from the uprights 14a 14b, as shown in Figure 8, and intermediate floor joists 15 are shown in Figures 2a and 2b.
The roof and floor beams 12a, 12b, 13a, 13b are each of channel shape in cross-section and each includes a vertically disposed web 16 (see Figure 1),, the roof beams 12a, 12b having laterally inwardly directed horizontal flanges 17 and 18, and the floor beams 13a, 13b laterally inwardly directed flanges 17a, 18a.
The uprights 14a, 14b are of rolled hollow section or alternatively of channel section. The flanges 17, 18, 17a, 18a, all have inwardly directed lips at their free ends.
The enable the beams 12a, 12b, 13 a, 13b and uprights 14a, 14b to be connected rigidly together, the beams 12a, 12b, 13a, 13b are butted directly against the uprights 14a, 14b and secured thereto by means of an angle bracket B bolted or welded to the web 16 and flange 20 of the uprights 14a, 14b.
The floor joists 15 are also channel shape in cross-section and each comprises a vertical web 23 with horizontal directed flanges 24 and 25, the upper flange 24 having a downwardly directed lip 24ʹ at its free edge.
It will thus be seen that each sub-frame 11a, 11b affords a rectangular aperture defined by the beams and uprights 12a, 13a, 14a and 12b, 13b, 14b, respectively which may be closed by end and side wall panels as hereinafter described.
Lifting eyes 27 are removably secured to the tops of the uprights 14a, 14b by bolts 27a which engage a nut 27b.
Referring now to Figures 1 to 3, the module illustrated includes a floor structure 30 comprising an upper sheet of wood particle board 31 which rests at its lateral margins on the upper flanges 18a of the lower beams 13a, 13b and is supported on the floor joists 15.
A foil faced film or blanket 32 underdraws the floor joists 15 and is secured to the bottom flange 25 thereof of each joist by pneumatically driven nails N and galvanised washers, or self drilling screws or other suitable fasteners.
The foil facings of the thermal blanker, act in combination with the air gap created under the floor deck provided by the board 31 to reflect radiated heat from the floor back into the building. Since the natural direction of convective heat flows upwards, this gives a warm layer of air just below the floor deck 31. The thermal blanket is in one-piece with no gaps and thus prevents draughts.
Possible cold-bridging is avoided as the thermal blanket covers the bottom of the steel joists 15. The thermal blanket 32 has a Class 1 surface spread of flame, which assures a safe fire preformance and has a life in excess of forty years and is not affected by moisture.
To enable the whole structure to be supported on a lorry affording a bed narrower than the overall width of the building module, longitudinal wooden bars 37 are secured in position beneath the joists 15 inwardly of the ends of the module.
A roof panel 40 extends between and is secured to the roof beams 12a, 12b therebelow by attachment to the lower flanges 17 thereof. The roof panel 40 comprises an inner skin 41 or plastic coated steel, and outer skin 42 also of plastic coated steel, a timber perimeter framework, part of which is shown at T, with the space between them being filled by a foamed plastic material 43, which in the present example is polyurethane foam.
The inner skin 41 comprises a plurality of planar plastic coated steel sheets 41a e.g. seven. In the present example, the plastic coating is that commonly known as a "low gloss Dolomite architectural polyester". The seven sheets are disposed side-by-side longitudinally of the roof panel and each sheet extends across the whole of the transverse extent of the roof panel. The adjacent edges of the sheets are crimped together, as shown at 44 in Figures 5 and 6.
The outer skin 42 comprises a plurality of profiled plastic coated steel sheets 42a, e.g. three the plastic coating in the present example providing a silk grey plastisol coating.
Each sheet extends throughout the longitudinal extent of the roof panel and the sheets are disposed in side-by-side relation across the transverse extent of the roof panel with adjacent side portions in overlapping relationship so that the adjacent end two corrugations partially overlap as shown at 45a, 45b in Figure 7.
A sealing strip is provided at the apex of the outer pair of overlapping corrugations as shown at 46. The roof panel is manufactured by assembling the sheets 41a of the lower skin 41 in crimped relationship in a jig, positioning roof blocks 47 of diamond configuration at the locations shown in Figure 4, assembling the peripheral frame T, the members of which are secured together by corrugated plates, on top of the sheets of the lower skin, and positioning dividers 49 adjacent the crimped together seams 44. Each divider 49 comprising a base part 49a of plywood and an upper part 49b of expanded polyurethane foam material, the upper surface of which has a configuration corresponding to the configuration of the profile of the sheets 42a of the upper skin 42. These dividers 49 serve to divide the roof panel into sections which are filled, after assembly of the sheets 42a of the upper skin 42 on top of the previously described components through injection grooves 50 provided on the upper surface of one longitudinally extending member of the frame T.
Also assembled in the jig adjacent each divider 49 is a transversely extending reinforcing member 51 made of steel and of assymetric channel configuration comprising a web 52 disposed vertically so as to extend normal to the general plane of the inner and outer skins 41, 42ʹ, a lower limb 53 of relatively short extent and an upper limb 54 of relatively longer extent, in the present example approximately twice as long as the limb 53. The limbs 53, 54 are disposed so as to extend perpendicular to the web part 52.
If desired the reinforcing member 51 may be disposed at different positions and a different number of reinforcing members may be provided than described above. Each reinforcing member may be of different shape and/or different material than described above.
At each end, the limb 54 projects longitudinally outwardly of the web part 52 and lower limb 53 so as to overlie the longitudinally extending members of the frame T to be received in a rebate 55 formed therein, so that the upper surface of the limb 54 is flush with the upper surface of the longitudinally extending frame member. The lower limb 53 is spaced above the skin 41 so that when foam insulating material, in the present example polyurethane foam, is injected into the sections through the grooves 50, insulating material enters the space between the undersurface of the limb 53 and the upwardly facing surface of the skin 41, so as to avoid cold bridging between the inner and outer skins through the transverse reinforcing members 51.
The sheets 42a of the upper skin 42 stop short of the longitudinally extending members of the frame T and a steel strip 57 is arranged in overlapping relationship with the edge of the sheets 42a adjacent the associated frame member T with a sealant 58 therebetween, whilst the other end of the strip 57 is nailed to the frame member T.
The transversely extending ends of the sheets 42a are nailed in the valleys to the transversely extending members of the frame T where the three sheets overlap so that the bottom roof sheet is penetrated by the nail and the nail head covered by the top sheet. The ends of the sheet which is to provide the upper end of the roof panel, in use, are bent upwardly through 90°, whilst at the other end, the sheet is bent downwardly through an angle of approximately 20° so that water cannot flow from the valleys at the upper end because of the upturn and the downturn facilitates flow therefrom. A weatherproof membrane, e.g. Hypalon sheet H is nailed below the valleys of the bottom sheet at the lower end and the roof member T to provide a discharge path for water.
The plywood base part 49a of the dividers 49 project longitudinally outwardly beyond the upper part 49b and are received in a slot 58 formed in the longitudinal frame members T.
The roof sheets are positioned below the lower flanges 17 of the roof beams with spacers 59 therebetween. The spacers 59 increase in height from one end of the roof panel to the other so that the rood panel is inclined downwardly as the spacers 59 increase in height relative to the roof beams 16 so that water is discharged from the lower end of the roof panel. The angle of inclination may lie in the range 1 in 120 to 1 in 60 depending upon the application of the building.
A suitable trim fitting 61 is provided between the roof beams 16 and the roof panel with a suitable sealant therebetween.
The connection between the roof panel and the beam 16 comprises a plurality of bolts 62 which pass through apertures formed in the lower skin 41, longitudinally extending frame members T, projecting part of the upper limb 54 and the flange 17 of the roof beams 16.
Thus, whilst the vertical sub-frames 11a, 11b of the rigid frame 10 are connected at the bottom by the joists 15, no frame parts interconnect the sub-frames 11a, 11b at the top, the sub-frames being structurally interconnected solely by the roof panel 40.
It has been found surprisingly, that the roof panel 40 described above provides sufficient strength to hold the sub-frames 11a, 11b rigidly apart at their upper ends and thus serve a similar function as would metal frame cross members. This is particularly due to the reinforcing members 51. It has further been found that this construction has advantages compared to conventional structures having metal cross members because cold bridging is reduced, because of the thermally insulating foam in the gaps 56 between the reinforcing members 51 and the inner skin 41, as well as the timber of the periphals frame T being a better insulater than metal. Thus condensation, which can occur in metal framed buildings, is reduced. Another advantage with this construction is that the structure is considerably simplified and costs in producing such building are accordingly reduced.
Secured to the frame are end wall panels 70 and side wall panels 80, although one of the end wall panels 70 and/or side wall panels 80 may be omitted to enable the unit to be lined to other similar units, to provide multi-building construction, by bolting the sub-frames of such adjacent units directly together to bring the floors and end wall panels of such units into direct abutting relation as shown in Figure 3.
The end wall panels 70 are secured to the inside of the uprights 14a, 14b by attachment to the inner flanges 20 thereof so that the panels 70 are received entirely within the metal frame 10. Such end wall panels comprise an outer skin 71 of plastic coated steel, and an inner skin 72 of plasterboard, secured to a framework of timber members 73 and with foamed plastics insulation material 74 therebetween.
The end and side wall panels 70, 80 add further rigidity to the structure. Where two or more units are linked, an internal trim strip may be provided if desired to cover the joint between adjacent end or side wall panels 70, 80.
Whilst one side of the illustrated unit in Figure 3 is left open to provide a full width connection with an adjacent similar unit, the other side is closed by means of a side wall panel 80 (Figure 1) attached to the vertical frame 11a, externally thereof. The side wall panel 80 is of similar construction to the end wall panel 70 and includes an outer skin 81 and an inner skin 82 secured to a framework of timber members 83 with foamed plastics insulation material 84 therebetween.
The edges of the side and end wall panels are masked by appropriate trim strips and a gutter 90 and drain pipe 91 positioned at the lower end of the roof panel.
Although not shown, the end and side wall panels, where provided, may be equipped with all necessary doors and windows, and the windows may be single or double glazed as required.
All required internal fittings, including partition walls, carpeting or other floor covering, and appropriate mains services such as gas, electricity, water supply and sanitation may be be provided so that the complete unit may be delivered to a prepared site, ready for use, subject only to securing adjacent units together where necessary and applying internal trim strips as necessary at the joints between adjacent units, and if required external trims.
When two or more units are connected together in end-to-end configuration, the higher ends may be adjacent with suitable guttering being provided at the lower ends.
If desired, a plurality of roof panels may be provided secured to an below the roof beams instead of a single roof panel.
The features disclosed in the foregoing description, or in the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, may, separately or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

Claims

1. A roof structure, for a building module, characterised by the provision of a pair of spaced parallel roof beams interconnected solely by one or more roof panels, the or each roof panel comprising an insulated structural sandwich having inner and outer skins and having therebetween an insulating infill and at least one transverse reinforcing member disposed intermediate the ends of the panel.

2. A roof structure according to Claim 1 wherein the or each panel comprises a pair of spaced parallel side members and the or each reinforcing member extends between and is connected to the side members.

3. A roof structure according to Claim 2 wherein each side member and/or each transverse reinforcing member is connected to an associated roof beam.

4. A roof structure according to Claim 2 or Claim 3 wherein the or each transverse reinforcing member comprises a channel section with the web of the channel extending generally perpeniduclar to and between the inner and outer skins and one limb of the channel extending generally parallel to and adjacent the outer skin and being of greater length than the other limb, which is disposed closer to the inner skin and generally parallel thereto.

5. A roof structure according to Claim 4 wherein the one limb projects lengthwise of the reinforcing member beyond the web and overlies a portion of the side member at each end of the reinforcing member.

6. A roof structure according to any one of the preceding claims wherein the or each panel comprises at least one transverse divider to divide the or each panel into a plurality of sections. each of which is filled with said infilling during manufacture.

7. A roof structure according to any one of the preceding claims wherein the or each roof panel is secured to the roof beams so as to be disposed below the roof beams.

8. A roof structure according to Claim 7 wherein the or each roof panel is secured to the roof beams so as to be disposed below the roof beams at a distance which increases from one end of the roof structure to the other.

9. A roof structure according to Claim 2 or any one of Claims 3 to 8 when dependent upon Claim 2 wherein the reinforcing member, the inner skin and the side members or the or each roof panel are directly connected to the roof beams to ensure structural continuity but with the provision of spacer members, as appropriate, to provide the roof panels with a desired sloped.

10. A building module comprising a structural metal frame comprising a pair of lateral vertical sub-frames, each of said sub-frames including an upper member and a lower member, the upper and lower members of each sub-frame being inerconnected by uprights, and the lower members of the sub frames being rigidly interconnected in spaced apart parallel relation by frame cross members which extend between the lower members and the upper members of the sub-frames comprising said spaced parallel roof beams of a roof structure according to any one of Claims 1 to 9.

11. A module according to Claim 10 wherein at least one side wall panel is secured to the outside of the associated vertical sub-frame so that the members which comprise the associated sub-frame are inside the side walls and at least one end wall panel is received substantially entirely within an end opening defined between the sub-frames so that the members which make up the sub-frames lie peripherally of the end wall panel and wholly external to habitable volume of the module.

12. A module according to Claim 11 wherein the wall panels comprise a structural sandwich comprising an outer metal skin and inner skin sandwiching therebetween an insulating filling.