GB2345718A - Construction and location of a modular roof structure containing accommodation spaces - Google Patents

Abstract

A method for constructing a modular roof structure 5 by placing one or more roof modules 1-5 onto a building, the or each module containing space for living, working, storage or building services. The method comprises determining a desired disposition with respect to the building for a first location means, such as rails, attaching said first location means, reproducing said desired disposition in a second location means housed in a separate manufacturing facility, building or configuring the or each roof module on said second location means, transporting said modules to the building and locating said modules upon the first location means. Sealing means may be placed between adjacent modules. A modular roof system and a module for such a system are also disclosed.

Description

Modular Roof Svstem The present invention relates to the design, construction and installation of a modular roof system made up of one or more modules or units, where the resulting roof space is preferably usable as living or working accommodation.

The invention takes as its starting point the constant need for low-cost but goodquality accommodation. This need is felt especially by local authorities responsible for housing families of modest income, but applies of course in many other domestic and commercial circumstances. In most if not all cases, budgetary constraints make it desirable to exploit existing buildings wherever possible but where such buildings are too small for their intended purpose or are in a very poor state of repair, there is pressure to build anew rather than make the best of what is already available. The invention seeks to address this wastefulness of land and other resources by providing a way to use existing buildings for new and better purposes. The invention also seeks visually to enhance existing buildings, to general social benefit.

Many existing buildings have flat roofs, especially among commercial buildings and those used for local authority housing. Flat roofs tend to be unattractive unless they can be used constructively, for example as gardens and/or terraces, and suffer from well-documented disadvantages including poor weatherproofing and insulation that in many cases have led to the early abandonment of buildings that include them. The present invention therefore particularly contemplates a way of using flat roof spaces in a constructive and visually attractive manner, although the invention can also be employed to replace a redundant pitched roof structure if desired. Also, whilst the present invention is primarily concerned with making use of existing building stock, aspects of the invention can be applied to the construction of new buildings, as will become clear.

A building is usually constructed by installing foundations and floors, constructing a framework for the main structure and then fitting the elements that make up the walls, ceiling and roof to form a shell. Mechanical and electrical installations and other finishing operations follow completion of the shell.

Buildings may also be constructed using prefabricated modules built off-site and subsequently transported to the site and assembled in situ. The benefits of this method include assembly of the modules in a factory-controlled environment as well as use of standardised elements, thus reducing manufacturing costs, site construction times, labour costs and hence the ultimate building costs. Modular building units and their methods of construction are well known, as illustrated in, for example, US Patent Nos.

5,644,871 and 5,524,412.

More typically, however, the roof of a building is constructed on-site in component form above ground level, requiring scaffolding, skilled labour, fair weather and so on.

All of these factors add to the cost of this element of the structure and increase the risk of contract penalties due to delay: the roof therefore represents a disproportionately high percentage of the overall cost of a building. Similar considerations apply to the renovation of an existing roof structure. In either case, there is a highly-desirable economic advantage in constructing a roof in modular fashion at ground level and then lifting the or each finished module into position.

US Patent No. 5,274,967 describes a non-transportable roofing assembly which is specifically designed to be assembled on the ground adjacent the building and lifted into position as an assembly using a crane. The invention described therein forms part of a fast construction system and involves some off-site construction of service room modules, such as kitchens and bathrooms. However, the invention of US 5,274,967 suffers from the disadvantage that a substantial amount of space around or near to the building site is required in order to construct the roof assembly, and that such conditions are hardly factory-controlled. Also, there is no suggestion that the assembly is modular and therefore the larger the roof area to be covered, the larger the space required for construction. Lifting a large roof structure a substantial height also incurs problems, including the need to make the roof assembly suitably rigid while minimising the overall weight of the assembly. US 5,274,967 also provides no information as to how the roof assembly is connected to the existing building.

Japanese laid-open Patent Application No. 96093114 describes an invention whose aim is to overcome the problems of building a very large roof structure, such as one weighing several hundred tonnes as may be required, for example, to cover an atrium of an event hall. The roof is assembled on temporary supports beside the corresponding opening that the roof is intended to cover and, when assembled, is slid along rails into position over that opening. Once the roof is correctly positioned, the temporary supports are removed and the roof is fixed in that position. However, the problems addressed by JP 96093114 are peculiar to very large roof structures and it will be noted that assembly of the roof structure still takes place above ground level, with its attendant disadvantages.

In contrast, preferred aspects of the present invention seek to provide means of attaching to the roof of a building one or more factory-built roof modules. This minimises cost, makes use of previously redundant roof space, and enhances the visual aspect of an existing building. More specifically, the invention contemplates the use of lightweight prefabricated inter-linking accommodation modules that are substantially finished before delivery to the site. Each module should be of a size and weight that is transportable using a standard freight vehicle such as a flat-bed lorry or truck and that can be lifted up to at least the eighth floor level by a transportable crane.

Once lifted to roof level, the modules can be linked together to form the proposed accommodation, be it for a residential, commercial or other purpose such as a school extension.

Of course, it has long been known to use prefabricated accommodation modules, notably those sold in the United Kingdom under the trade mark PORTACABIN.

These can be transported by road, hoisted into position beside or atop one another, and linked together to form accommodation of nearly any desired shape or size. However, these modules are of an overtly standardised design which make them suitable for use together but ill-adapt them to integrate with an existing building with all of its dimensional, structural and visual variations. They neither fit an existing building in an integrated manner nor do anything to improve its visual amenity.

From a first aspect, the invention encompasses a method of constructing a modular roof structure by placing one or more roof modules onto a building, the or each module containing space for living, working, storage or building services, the method comprising : determining a desired disposition with respect to the building for a first location means adapted to locate the or each roof module in a desired location with respect to the building; attaching the first location means to the building in said desired disposition; reproducing said desired disposition in a second location means housed in a separate manufacturing facility and substantially corresponding to the first location means; building or configuring the or each roof module on said second location means in a manner to suit the desired location ; transporting the or each built or configured roof module from the second location means to the building; and locating the or each built or configured roof module upon the first location means in said desired location with respect to the building.

This method can preferably be applied to an existing building, in which case the method may further comprise surveying the building to determine its dimensions and load-bearing structure when determining the desired disposition of the first location means. In any case, the first location means can be attached to the building at any time before a module is first located on it.

This aspect of the invention has the great advantage that once built or configured upon the second location means, a roof module will fit the first location means with minimal or no adjustment. This minimises time spent on-site, greatly reduces the costs and inconvenience of construction, and ensures accurate positioning of a module t ( the benefit of weatherproofing and so on.

The desired disposition of the first location means will take into account matters such as the location of load-bearing walls (generally spine or peripheral walls), it being highly advantageous for the location means to feed the weight loads of the roof structure into the load-bearing walls. The disposition of the first location means should also take account of the desirability that the location means comprises one or more rails so that the or each module can be moved along the rail in an appropriate direction during installation.

Attaching the first location means to the building may be achieved by, for example, bolts or other fixing means such as adhesives.

The desired disposition may be reproduced and maintained in the separate manufacturing facility by attaching the second location means in said disposition to a fixed datum such as a jig or the floor of the manufacturing facility.

Whilst it is mainly envisaged that a module will be built on the second location means, it is also possible to configure an already-built module on the second location means to ready it for location on the first location means.

Locating the or each built or configured roof module upon the first location means may be achieved by attaching the roof module to the first location means, preferably by bolts or other positive fixing means. Before final attachment and as mentioned above, the roof module is preferably moved along the first location means during installation. Thus, where the first location means comprises a rail, a roof module can be advanced along the rail into its final position and other modules can similarly be advanced into abutting relationship with each preceding module, whereupon the modules can be attached and preferably sealed to each other to make a space-creating roof structure.

Sealing and/or attachment between modules or between a module and the building may be aided by moving at least part of a module transversely with respect to its general direction of movement during installation. This transverse movement can be achieved by, for example, providing removable wedge or ramp means associated with a rail-based first location means.

A further advantage of a rail-based first location means is that no damage is caused to an existing building as modules are slid into position.

In addition to the attachment of the first location means, an existing building may be prepared to receive a roof module by the provision of accesses through the existing roof for stairs, a lift etc., adaptation of soil and vent pipes and other services, and connection of mechanical and electrical supplies to distribution heads.

Whilst it may be necessary to finish a module after attachment to the first location means on the building, it is preferred that a module is substantially finished and decorated prior to delivery.

The invention also encompasses a modular roof system comprising one or more prefabricated modules located by location means carried by a building, the or each module containing space for living, working, storage or building services, the location means being adapted to receive the or each module when lifted onto the building, to guide movement of the or each module into a desired position with respect to the building during installation and thereafter to feed the weight load of the or each module into the load-bearing structure of the building.

In another aspect, the invention extends to a roof module defining space for living, working, storage or building services, the module comprising at least one variablepitch wall unless the module is an infill to create a larger volume accommodation area.

In order that the present invention may be more easily understood, reference will now be made, by way of example, to the accompanying drawings, in which: Figure 1 is an aerial perspective view of a block of flats or apartments typically built for local authority use, showing the building without a roof to illustrate the position of its load-bearing walls ; Figures 2a and 2b are sectional end views of two embodiments of a roof module of the invention in place on a flat roof, Figure 2a illustrating how a roof module may be placed within an existing parapet on the roof and Figure 2b illustrating a roof module positioned on a roof without such a parapet; Figure 3 is a flow chart outlining the stages of the method from placing an order through to finishing of the new roof structure; Figure 4 is a schematic perspective view showing an embodiment of a roof constructed from a number of inter-linking roof modules; Figures 5 (a) and 5 (b) are sectional end views of a roof module during fabrication in a factory, Figure 5 (a) being a section through the roof module, showing attachment means corresponding to those fixed to the peripheral and spine walls of an existing building, and Figure 5 (b) showing a detail of an edge region of Figure 5 (a) to illustrate the attachment of the roof module to the factory floor which therefore acts as a jig; Figures 6 (a), (b), (c) and (d) are a series of diagrams outlining the installation of first and second roof modules onto a roof, Figure 6 (a) showing one roof module (A) fixed in position on an existing flat roof, Figure 6 (b) showing wedges positioned beside roof module A, Figure 6 (c) showing a second roof module (B) being moved into position beside module A and being ramped into position with the aid of the wedges to facilitate the application of sealant between modules A and B, Figure 6 (d) showing the abutment of modules A and B once the wedges have been removed and including a detail view of the sealant between modules A and B; and Figure 7 is a sectional end detail of the lower edge of one side of a roof module fixed to a wall via attachment means.

Figure 1 shows in perspective a view from above a typical block of flats or apartments 1 built for local authority use, with the common flat roof of such a building having been stripped away to show the peripheral 2 and spine 3 walls that bear the weight of the roof. A stairwell 4 is also visible. A similarly-arranged pitched-roof building would look much the same once the roof structure has been removed: such a building is also a suitable basis for use of the invention. Commercial or industrial units can have a similar structure, although they will usually place less reliance upon spine walls so as to allow a greater uninterrupted floor area between the peripheral walls.

The roof of a building such as that illustrated in Figure 1 represents an opportunity to add on one or more additional floors of accommodation, provided that the structure of the existing building is strong enough to support the extra weight. Adding accommodation units to an existing roof provides additional space for living, working, storage or building services such as air conditioning. However, as will be appreciated and as can be seen in Figure 1, many existing buildings are not of a regular rectangular plan shape, although standard units can be utilised to assist manufacture but may require vary-pitched mansard type gable abutments.

Referring now to Figures 2 (a) and 2 (b), the modular factory-built roof assembly 5 of the present invention can overcome this problem by being tailored at the factory to the exact shape and size of the building in question, although elements of standardisation are retained. For example, individual modules 6 can be adaptable to suit different applications, possibly including means to vary the pitch of the roof from eaves level to match an existing neighbouring roof or to span a gap of particular width. A site-cut soffit board can be used where necessary to finish the structure by matching the selected pitch.

For optimum accommodation while preserving the pleasing appearance of a pitched roof 7, it is preferred that a mansard-style roof is adopted as best shown in Figures 2 (a) and 2 (b). These Figures largely correspond in all respects but it will be seen that the roof module 6 of Figure 2 (a) fits within a peripheral parapet 8 whereas there is no such parapet 8 in Figure 2 (b). Any tendency of the peripheral walls 2 to bulge outwardly under the downward load of the roof module 6 can be countered by a tie linking the peripheral walls 3 just under the roof module 6 as shown in Figure 2 (b).

Figure 3 is a flow chart outlining a preferred method of the invention starting from receipt of a customer order and progressing to completion of the roof structure.

Reference will be made to other Figures of the drawings as necessary to describe the preferred method.

Once an order has been placed, a surveyor attends the site to assess the situation and conduct a detailed site survey. As part of this, the surveyor takes photographs and measures the existing building 1, carries out a detailed survey of the roof and access to it and determines the client's requirements, as well as the position and standard of existing mechanical and electrical supplies and the requirements for connection of modules to the building. At this stage, planning permission will usually be sought and obtained although, if needs be, construction can proceed in the expectation of obtaining such permission.

Once the surveyor has obtained all necessary details, engineering calculations can be performed to determine the feasibility and execution of the planned work. Any necessary adaptations or alterations to standard modules 6 can be collated and presented by draftsmen in the form of detailed manufacturing drawings and given to the factory for construction of the required modules 6.

The factory proceeds to build the modules 6 on location means 10 supported in turn by a jig or even by being bolted directly to the factory floor 23 as shown in Figures 5 (a) and 5 (b), the disposition of the location means 10 in the factory replicating the intended disposition of the corresponding location means 10 that will eventually locate and support the modules 6 in the finished roof structure 5.

In preferred embodiments as illustrated in Figures 5 (a) and 5 (b), the location means 10 take the form of rails of a suitable and preferably standard steel section. The module is built on the rails 10 from decking beams braced with structural framework, all of high strength-to-weight steels such as are sold in the United Kingdom by British Steel under the trade mark SUREBUILD.

Construction of a module 6 on the rails 10 starts with the floor joisting or base of the module 11. This consists of lightweight cold-rolled steel sections and purlins which are laid across the rails 10 and clamped into position. Jumbo metal stud is erected on this base to create external wall elements 12, and proprietary lightweight metal studwork or joisting is fixed to the wall elements to provide a base for the roof covering. Metal stud partition sections are then erected to create internal partitions and soffit framework.

If necessary, the basic structure of the module 6 can be strengthened locally around any planned lifting and mounting points, for example by incorporating additional or thicker structural members. Lifting points can be permanent or temporary, in the sense that they can either be left on the module or removed upon installation.

Next, prefabricated PVUC doors and windows, usually dormer units, are fixed in prepared openings in the wall elements and the external faces of the module are clad with roofing materials that suit the designer's requirements in terms of appearance and function. These materials may, for example, be lightweight artificial slates 19 or other lightweight proprietary roofing systems such as are sold in the United Kingdom by Tufftile Roofing Systems Limited under the trade marks TUFFTILE or TUFFSLATE.

The tiles or slates 19 can be hung on timber battens supported in turn by timber rafters attached to the underlying metal framework.

Voids are maintained in the flooring or partitioning of a module to accept mechanical and electrical services and suitable thermal or acoustic insulation such as slab insulation. That done, floors and walls/ceilings, typically of chipboard and plasterboard respectively, are applied and carpeted or decorated as needs be. Normal second fix applications can be carried out to the standard required for their end use, even to the extent of fitting kitchen and bathroom appliances.

While the factory is building the modules 6 in this way, an enabling team attends the site to prepare the structure 1 for the arrival of the modules 6 from the factory. The enabling team forms access openings through the roof for stairwells, lift voids and so on, making additions and alterations to the stairs and lifts as necessary. The enabling team is also responsible for siting and fitting location means 18 in the form of rails in exact correspondence with the layout of the rails 10 on the factory jig or factory floor 23 and for bringing up mechanical and electrical supplies to distribution heads.

Adaptation to soil and vent pipes and other services is also carried out by the enabling team at this stage.

The rails 18 are fixed to the load-bearing walls 2,3 of the building, notably the peripheral walls 2 and (where applicable) the spine wall (s) 3, thereby to feed loads from the new roof structure 5 to the existing load-bearing elements of the building 1.

When finished, the modules 6 are transported to the site by conventional road transport and lifted to roof level by crane 13. As shown in Figure 6 (a), the first unit 14 is lowered onto the rails 18 placed by the enabling team, slid in a first direction into position and fixed by means such as bolts 9. Subsequent units may then be similarly positioned and fixed. As illustrated in Figure 4, the roof assembly 5 will usually be built up of a number of prefabricated modules 6. However, if the roof area to be covered is not too large, it may be possible to use only one module 6.

Once the or each module 6 is in position, any ancillary works can take place including mechanical and electrical connections to the feeds left by the enabling team, connections being made to prepared tails and jointing points set at convenient locations planned during assembly. During this phase, any abutments required to existing stairwells, lift voids etc. are carried out.

It is preferred that mechanical, electrical and soil connections between modules 6 and between the modules 6 and the supporting building 1 are made via proprietary flexible plug-in adaptors. This provides a measure of tolerance against misalignment and so eases construction, as does the simple plug-in nature of the adaptors.

If the existing building 1 had equipment such as AC modules, transmission or receiving aerials or dishes etc. at roof level, they would be disconnected at the outset by the enabling team, set aside before the modules 6 were craned up to roof level, and re-fixed and connected to pre-prepared mountings incorporated during assembly of the modules 6.

The completed structure 5 is now ready to receive any minor finishing necessary and to be made ready for use.

Where more than one module 6 is required, it is preferred that adjacent modules abut at a partition junction but if this is impractical, a pre-finished face-fixed section can be fitted after installation.

In any event, a good seal between adjacent modules 6 is required to minimise the water seepage and frost damage that would inevitably lead to structural damage of the roof assembly. In this respect, once the first module 14 is fixed in position as show-n in Figure 6 (a), a second, adjacent module 15 is aligned on the rails 18 and moved towards the first module and into mutual abutment as shown in the sequence of diagrams 6 (b) to 6 (d). To aid sealing, it is advantageous if the leading edge 21 of the second module 15 moves transversely to the movement of the second module 15 towards the first module 14 during installation, thereby allowing sealant to be applied to the abutting edges.

In the preferred embodiment of Figures 6 (a) to 6 (d), this transverse movement is achieved by raising the leading edge 21 of the second module 15 upon wedges 17 placed on the rails 18 beside the first module 14 as shown in Figure 6 (b). The second module 15 is moved into position abutting the first module 14 as shown in Figure 6 (c) and sealant 16 is applied to the exposed edges of the modules 14,15 before the wedges 17 are removed and the second module 15 is lowered into place so that, as the module 15 is lowered, the sealant 17 is pulled in between the two modules 14,15to create a good seal as shown in Figure 6 (d) and its associated detail view.

Finally, the detailed sectional view of Figure 7 shows the manner in which a roof module 6 is attached to an existing building 1 via the location and/or attachment means 18 described above. Specifically, the module 6 rests upon and is bolted to a Csection rail 18 that may be bolted or bonded by epoxy adhesive along the top edge of a peripheral wall 2. It can be seen that a fascia and soffit 20 depend like a skirt from the tiled exterior of the module 6 around the eaves, aiding weatherproofing and covering the location and/or attachment means 18 so that the finished structure 5 appears as a typical roof.

The invention in its various aspects minimises disruptive and expensive time on site and provides an elegant solution to the need for new and renovated buildings having additional space for working, living, storage and building services.

It will be appreciated that the present invention may be embodied in other specific forms without departing from its essential attributes.

Claims (28)

1. Claims: 1. A method of constructing a modular roof structure by placing one or more roof modules onto a building, the or each module containing space for living, working, storage or building services, the method comprising: determining a desired disposition with respect to the building for a first location means adapted to locate the or each roof module in a desired location with respect to the building; attaching the first location means to the building in said desired disposition ; reproducing said desired disposition in a second location means housed in a separate manufacturing facility and substantially corresponding to the first location means; building or configuring the or each roof module on said second location means in a manner to suit the desired location ; transporting the or each built or configured roof module from the second location means to the building; and locating the or each built or configured roof module upon the first location means in said desired location with respect to the building.
2. 2. A method according to claim 1, wherein the method is applied to an existing building.
3. 3. A method according to claim 1 or claim 2, and further comprising surveying the building to determine its dimensions and load-bearing structure when determining the desired disposition of the first location means.
4. 4. A method according to any of claims 1 to 3, wherein the first location means is attached to the building at any time before a module is first located on it.
5. 5. A method according to any preceding claim, wherein the first location means feeds the weight loads of the roof structure into the load-bearing structure of the building.
6. 6. A method according to any preceding claim, wherein the first location means comprises one or more rails along which the or each module is moved during installation.
7. 7. A method according to any preceding claim, wherein the first location means is attached to the building by fixing means.
8. 8. A method according to claim 7, wherein the fixing means comprises bolts or adhesives.
9. 9. A method according to any preceding claim, wherein the desired disposition of the first location means is reproduced and maintained in the separate manufacturing facility by attaching the second location means in said disposition to a fixed datum.
10. 10. A method according to claim 9, wherein the fixed datum is a jig or the floor of the manufacturing facility.
11. 11. A method according to claim 9 or claim 10, wherein an already-built module is configured on the second location means to ready it for location on the first location means.
12. 12. A method according to any preceding claim, wherein the or each built or configured roof module is located upon the first location means by attaching the roof module to the first location means.
13. 13. A method according to claim 12, wherein the or each built or configured roof module is attached to the first location means by bolts or other positive fixing means.
14. 14. A method according to any preceding claim, wherein the roof module is moved along the first location means before final attachment.
15. 15. A method according to claim 14, wherein a roof module is advanced along the first location means into its final position and one or more other modules are similarly advanced into abutting relationship with the or each preceding module to make a space-creating roof structure.
16. 16. A method according to claim 15, wherein the modules in abutting relationship with each other are sealed and/or attached to each other.
17. 17. A method according to claim 16, wherein sealing and/or attachment between modules or between a module and the building is aided by moving at least part of a module transversely with respect to its general direction of movement during installation.
18. 18. A method according to claim 17, wherein the transverse movement is achieved by providing removable wedge or ramp means associated with a rail-based first location means.
19. 19. A method according to any preceding claim, wherein an existing building is prepared to receive a roof module.
20. 20. A method according to claim 19, wherein preparation of the existing building includes the provision of accesses through the existing roof for stairs, lift etc., adaptation of soil and vent pipes and other services, and/or connection of mechanical and electrical supplies to distribution heads.
21. 21. A method according to any preceding claim, wherein a module is finished after attachment to the first location means on the building.
22. 22. A method according to any of claims 1 to 20, wherein a module is substantially finished and decorated prior to delivery.
23. 23. A modular roof system comprising one or more prefabricated modules located by first location means carried by a building, the or each module containing space for living, working, storage or building services and being built or configured on second location means housed in a separate manufacturing facility and substantially corresponding to the first location means.
24. 24. A modular roof system according to claim 23, wherein the location means is adapted to receive the or each module when lifted onto the building, to guide movement of the or each module into a desired position with respect to the building during installation and thereafter to feed the weight load of the or each module into the load-bearing structure of the building.
25. 25. A roof module adapted for use in the modular roof system of claim 23 or claim 24.
26. 26. A roof module according to claim 25, wherein the module comprises at least one variable-pitch wall.
27. 27. A method of constructing a modular roof structure, substantially as hereinbefore described, with reference to Figures 3 and 6 of the accompanying drawings.
28. 28. A modular roof system or a roof module for said system, substantially as hereinbefore described, with reference to or as illustrated in any of Figures 2a, 2b, 4,5 and 7 of the accompanying drawings.