EP0058354B1

EP0058354B1 - Portable building unit

Info

Publication number: EP0058354B1
Application number: EP19820100834
Authority: EP
Inventors: Stephen Wentworth Stericker; Peter Woodman; Stephen Walter Newton; Peter Mansell Roberts
Original assignee: Portakabin Ltd
Current assignee: Portakabin Ltd
Priority date: 1981-02-07
Filing date: 1982-02-05
Publication date: 1984-08-01
Also published as: DE3260479D1; EP0058354A1

Description

This invention relates to a portable building unit which may be assembled with further similar units to provide a building construction. Each unit is fully factory assembled for delivery to a prepared site in an assembled condition complete with at least floor and roof.
More particularly, the or each unit comprises a structural metal frame to which the floor and roof structures are attached. Where such units are to be assembled together to form a multi-unit building construction the structural frames are butted or otherwise connected together in the desired arrangement.
I n 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 units.
Such portable building units will hereinafter be described as ,,of the type described".
Such a building unit of the type described is disclosed in DE-A-1,684,851. However, this unit has problems with cold bridging in the roof structure because the cross beams which interconnect the sides at the top and support the roof structure are made of metal and lie inside the habitable volume of the unit. This leads to heat exchange through the roof and condensation where the outside temperature is sufficiently low.
An object of the invention is to provide a new and improved portable building unit of the type described.
According to the present invention we provide a portable building unit 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, a floor structure extending between and being supported by the lower members of said sub-frames, characterized in that the upper members of the sub-frames are interconnected solely by one or more roof panels the or each of which extend between and is secured below the upper members of said sub-frames so that the upper frame members are wholly external to the habitable volume of the unit, and the or each roof panel, or the or each roof panel and the end and/or side wall panels, comprising an insulated structural sandwich having inner and outer sheets.
It has been found that the roof panel or panels can provide sufficient strength to hold the sub-frames rigidly apart at their upper ends and thus serve a similar function as a metal frame cross member would. It has been found further, that this construction has advantages compared to conventional structures having metal cross members because cold bridging is reduced, timber being a better insulator than metal, and thus condensation, which can occur in metal framed buildings, is also reduced. Another advantage with this construction is that the structure is considerably simplified and costs in producing such building are accordingly reduced.
Said sub-frames may define open sides of the unit whereby two or more similar units may be joined 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 unit with walls at one or both sides. Alternatively, or additionally, two or more units 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 unit.
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 be of similar construction to the roof panel or panels described above but the inner sheet may comprise plaster board or the like instead of metal as with the roof panel, if desired.
The floor structure may comprise a timber decking supported by a plurality of timber joists which extend between and are carried by the lower members of the sub-frames, with thermal insulation between such joists, such as a layer of glass fibre or other similar material supported on suitable panels positioned between the joists. Preferably, the decking, which may be of chip board or the like, extends across the upper faces of the lower members of the sub-frames, whilst the joists ' 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 flanges extending horizontally 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 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 bolted to the web of the upper or lower member as appropriate and to the inner flange of the channel section column.
Lifting attachments may be secured to the upper members or uprights of each sub-frame, preferably at respective positions immediately adjacent to the joint between the respective column and upper member.
The frame cross members which connect the lower members of the sub-frames preferably are connected to the sub-frames, at locations adjacent to the lower corners thereof. The cross members may each comprise a channel section beam, preferably arranged with the web thereof extending vertically and the flanges directed horizontally.
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 unit embodying the invention;
Figure 2 is a partial longitudinal section on a vertical plane;
Figure 3 is a horizontal section through an end wall of the unit, also illustrating the manner in which two adjoining units may be secured together;
Figure 4 is a perspective view of a rigid metal frame on which the building is constructed; and
Figure 5 is a fragmentary side view showing an inside detail of a corner joint in such frame.

Referring to the accompanying drawings, a building unit in accordance with the invention comprises a rigid frame 10 as shown in Figure 4, preferably constructed from channel section steel beams. The frame 10 comprises two vertical sub-frames 11 a, 11 b, each comprising respective upper horizontal beams 12a, 12b and lower horizontal beams 13a, 13b interconnected at their ends by uprights 14a, 14b. The two vertical sub-frames 11 a, 11 b are connected together by cross members 15 which extend between the lower beams 13a, 13b at positions adjacent to but spaced from the uprights 14a, 14b.
The upper and lower 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 upper beams 12a, 12b having outwardly directed horizontal flanges 17 and 18, and the lower beams 13a, 13b inwardly extending flanges 17a, 18a.
The uprights 14a, 14b are also of channel shape in section, and each includes a web 19 (Figure 5) and outwardly directed flanges 20 and 21. The flanges 17,18,17a, 18a, 20 and 21 all incorporate inwardly directed lips.
To enable the beams 12a, 12b, 13a, 13b and uprights14a, 14bto be connected rigidly together, the beams 12a, 12b, 13a, 13b are butted directly against the uprights 14a, 14b and secured by means of an angle bracket B bolted to the web 16 and flange 20 of the uprights 14a or 14b.
Alternatively, an end portion of the flanges may be cut away at one side to enable the end portion of the flange 19 of each upright 14a to be brought into face-to-face relation with an end portion of the web 16 of the adjacent beam, and the two webs directly bolted together. If desired, a corner plate may additionally be bolted to the webs of the beams and uprights.
The cross members 15 are also of channel shape in section, as seen in Figure 5, and each comprises a vertical web 23 with horizontally inwardly directed flanges 24 and 25, each having downwardly directed lips 24', 25' respectively at their free edges. An end portion 26 of the web 23 is turned inwardly and bolted directly to the web 16 of the adjacent beam 13a, 13b.
It will thus be seen that each sub-frame 11 a, 11b affords a rectangular aperture defined by the beams 12a, 12b, 13a, 13b and uprights 14a, 14b, for the reception of end and side wall panels as hereinafter described.
Lifting eyes 27 are secured to the tops of the uprights 14a, 14b by bolts 27a which engage a turned-over lip of the flange 20 thereof, and a reinforcing angle 27b as shown in Figure 2.
Referring now to Figures 1 to 3, the unit illustrated includes a floor structure 30 comprising an upper sheet of chip board 31 which rests at its lateral margins on the upper flanges of the lower beams 13a, 13b and is supported on the cross member 15 and further by transversely extending wooden joists 32, which joists are secured directly to the webs 16 of the beams 13a, 13b. Layers of fibre-glass or other similar mineral wool insulation 33 are supported between the wooden joists 32 on bitumen impregnated fibre board sheets 34 which themselves rest in position on staples 35 driven into the joists 32. The joists 32 are additionally supported at their ends on angle section members 36 carried by the webs of the lower beams 13a, 13b.
To enable the whole structure to be supported on a lorry affording a bed narrower than the overall width of the building unit, longitudinal bars 37 are secured in position beneath the joists 32.
A roof panel 40 is secured below the upper beams 12a, 12b by attachment to the lower flanges 17 thereof. The roof panel 40 comprises an inner skin 41 of plastic coated steel and an outer sheet 42 of plywood secured on a timber perimeter framework part of which is shown at T with the space between them filled by a foamed plastics material 43. A waterproof membrane 44 is provided across the upper face of sheet 42, and may also extend around the beams 12a, 12b, although as shown, a cap of weatherproof membrane W caps the beams 12a, 12b in the manner of a trim strip.
It can be seen that the vertical sub-frames 11 a, 11 b of the rigid frame 10 are connected at the bottom by the cross members 15, although no frame parts interconnect the sub-frames 11 a, 11 b at the top.
It has been found, surprisingly, that the roof panels 40 described provide sufficient strength to hold the sub-frames 11 a, 11 b rigidly apart at their upper ends and thus serve a similar function as a metal frame cross member would. This is particularly due to the perimeter members T of the panels 40. It has been found further, that this construction has advantages compared to conventional structures having metal cross members because cold bridging is reduced, timber being a better insulator than metal, and thus condensation, which can occur in metal framed buildings, is also 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 50 and side wall panels 60, although one of the end wall panels 50 and/or sidewall panels may be omitted to enable the unit to be linked to other similar units, to provide a multibuilding 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 50 are secured to the inside of the uprights 14a, 14b by attachment to the inner flanges 20 thereof so that the panels 50 are received entirely within the metal frame 10. Such end wall panels comprise an outer sheet 51 of coated steel, and an inner sheet of plasterboard 52 secured to a framework of timber members 53 and with a layer of foamed plastics insulation material 54 inbetween.
The end and side wall panels 50, 60 add further rigidity to the structure. Where two or more units are linked, an internal trim strip 55 may be provided if desired to cover the joint between adjacent end or side wall panels 60, 50.
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 60 (Figure 1) attached to the vertical frame 11 a, externally thereof. The side wall panel 60 is of similar construction to the end wall panel 50 and includes an outer sheet 61 of coated steel, and an inner sheet of plasterboard 62 secured on a timber sub-frame parts of which are shown at T' with foamed insulation material 64 between the inner and outer sheets 62, 61.
The edges of the side and end wall panels may be masked by appropriate trim strips, 58,59,67,68 and 69 as indicated.
Although not so 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 main services such as gas, electricity, water supply and sanitation may 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.
Although not evident from the drawings, the roof structure slopes slightly from end to end,to facilitate drainage. To achieve this, the vertical uprights 14a, 14b are longer at one end. When two or more units are connected together in end to end configuration, the higher ends may be adjacent, with suitable gutttering being provided at the lower ends.

Claims

1. A portable building unit comprising a structural metal frame (10) comprising a pair of lateral vertical sub-frames (11 a, 11 b), each of said sub-frames including an upper member (12a, 12b) and a lower member (13a, 13b), the upper and lower members (12a, 12b, 13a, 13b) of each sub-frame (11 a, 11 b) being interconnected by uprights (14a, 14b), and the lower members (13a, 13b) of the sub-frames (11 a, 11 b) being rigidly interconnected in spaced-apart parallel relation by frame cross members (15) which extend between the lower members, a floor structure (30) extending between and being supported by the lower members (13a, 13b) of said sub-frames (11 a, 11 b), characterized in that the upper members of the sub-frames being interconnected solely by one or more roof panels (40) the or each of which extend between and is secured below the upper members (12a, 12b) of said sub-frames (11 a, 11 b) so that the upper frame members (12a, 12b) are wholly external to the habitable volume of the unit, and the or each roof panel (40), or the or each roof panel (40) and the end and/or side wall panels (60, 50), comprising an insulated structural sandwich having inner (41) and outer (42) sheets.

2. A unit according to claim 1, wherein said sub-frames (11 a, 11 b) define open sides of the unit whereby two or more similar units may be joined together in side-by-side relation with full width linking.

3. A unit according to claim 2, wherein one or more side wall panels (50) is or are secured to the outside of an associated vertical sub-frame (11 a, 11 b) so as to provide a unit with a side wall (50) at one or both sides with the members which comprise the associated sub-frame (11 a, 11 b) inside the side walls (50).

4. A unit according to any one of claims 1 to 3, wherein the or each end of the unit is closed by one or more end wall panels (60), the or each end wall panel (60) being received substantially entirely within an end opening defined between the sub-frames (11 a, 11 b) so that the members which make up the sub-frames (11 a, 11 b) lie peripherally of the end wall panel or panels (60) and wholly external to the habitable volume of the unit.

5. A unit according to any one of the preceding claims, wherein lateral marginal portions of the roof panel (40) and floor structure (30) extend into the end and/or side openings defined by said sub-frames (11 a, 11 b).

6. A unit according to any one of the preceding claims, wherein the or each roof panel comprises a framework T to which the inner (41) and outer (42) sheets are secured.

7. A unit according to claim 6, wherein the inner sheet (41) of the or each roof panel (40) is a metal sheet (41) and the outer sheet is a timber decking (42).

8. A unit according to claim 6 or claim 7, wherein the end and/or side wall panels (60, 50) are each of similar construction to the roof panel or panels (40).

9. A unit according to any one of the preceding claims, wherein the floor structure (30) comprises a timber decking (31 ) supported by a plurality of timber joists (32) which extend between and are carried by the lower members (13a, 13b) of the sub-frames (11a, 11b), with thermal insulation (33) between such joists (32) supported on suitable panels (34) positioned between the joists (32), the decking (31 ) extending across the upper faces of the lower members (13a, 13b) of the sub-frames (11 a, 11 b) whilst the joists (32) extend between and are secured to the inner faces of such lower members (13a, 13b).

10. A unit according to any one of the preceding claims, wherein the upright members (14a, 14b) of each sub-frame (11a, 11b) are connected to the ends of the upper and lower members (12a, 12b, 13a, 13b) of the sub-frames (11 a, 11 b) and the frame cross members (15) which connect the lower members (13a, 13b) of the sub-frames (11 a, 11 b) are connected to the sub-frames at locations adjacent to the lower corners thereof.

11. A unit according to any one of the preceding claims, wherein the ends of the upper and lower members (12a, 12b, 13a, 13b) are each butted against an upright (14a, 14b) and secured thereto.

12. A unit according to any one of the preceding claims, wherein lifting attachments

(27) are secured to the upper members (13a, 13b) or uprights (14a, 14b) of each sub-frame (11 a, 11 b).