EP2872709A1

EP2872709A1 - Pitched roof structures and their methods of assembly and construction

Info

Publication number: EP2872709A1
Application number: EP13747481.3A
Authority: EP
Inventors: Timothy Michael BENSON; Phillip Mark KING
Original assignee: MODULOFT Ltd
Current assignee: Modugroup Ltd
Priority date: 2012-07-10
Filing date: 2013-07-05
Publication date: 2015-05-20
Anticipated expiration: 2033-07-05
Also published as: GB201312153D0; WO2014009702A1; EP2872709B1; GB2504001A; GB2504001B

Abstract

A method of assembly of at least one tiled pitched roof unit module is described, in which a plurality of truss units each incorporating a floor/ceiling joist and roof rafters fixed to the joists are assembled off-site to form a support framework for a roof covering, in which a floor/ceiling is optionally constructed across the floor/ceiling joists of the support framework, and in which the at least one tiled pitched roof unit module is provided with a roof covering of tiles which are fixed to the roof rafters of the roof support framework and in which the tiled pitched roof unit module is transported to, and assembled/installed on the tops of the walls of a building at, a building site. Also described is a method of assembling, on the walls of a building, a tiled pitched roof unit module having a ridge and two ends that face in opposite directions, which includes lifting the tiled pitched roof unit module from said oppositely facing ends and positioning the tiled pitched roof unit module on the tops of the building walls.

Description

Pitched Roof Structures and their Methods of Assembly and Construction

The present invention relates to pitched roof structures and modular pitched roof units for use in loft construction or conversion, to their methods of assembly and construction, to methods of installing such modular pitched roof units as described and claimed in the specification of UK Patent Application No. GB 212279.2 filed 10 July 2012, to an apparatus for use in the assembly of a modular pitched roof unit to be used in the assembly/construction of a modular roof unit for pitched roof construction, loft construction or conversion, to a roof unit module incorporating such an apparatus, and in particular to the apparatus comprising a demountable support beam apparatus table as described and claimed in the specification of UK Patent Application No. GB 212280.0 filed 10 July 2012 and from both of which applications this application claims priority. Such methods have utility in converting the roof space of an existing pitched roof structure or in the reroofing or initial construction of a building, in which the modular pitched roof is assembled/constructed from a single modular pitched roof unit or a plurality of modular pitched roof units. More particularly, but not exclusively, the present invention concerns methods of assembly of modular tiled pitched roof units on the tops of the walls of a building and tiled pitched roof structures formed from a plurality of such modular units.

As is well known, pitched roof structures have a support frame, usually of timber, and a roof covering, for example of tiles of clay or concrete or of sheets of metal such as flat formed or corrugated steel. The timber support frame is typically made from a plurality of truss units which are assembled onto the tops of the walls of a building on-site by fixing them to horizontally extending beams fixed to the walls.

Each truss unit includes two inclined roof rafters fixed at their lower ends to a floor/ceiling joist, as by nail plates, and joined together at their upper ends as by nail plates at what will ultimately be the ridge of roof. The roof rafters of the assembled truss units extend upwardly at an angle in spaced-apart side-by-side relationship from the respective beams, where they overhang to form the roof eaves to the ridge. Typically, the truss units overhang the walls to form the eaves of the roof where a fascia board is fixed to the lower ends of the truss units under the eaves. Guttering is fixed to the fascia board to receive run-off rain water and snow melt from the pitched roof covering. The truss units may be fabricated off-site and transported to the building site where they are assembled on-site to form the pitched roof structure. To guard against roof space condensation and provide a degree of insulation, an underlay such as a water/moisture resistant breather membrane or roofing felt is fixed to upper surfaces of the roof rafters to cover the rafters from the eaves to the ridge and tiling battens are fixed, as by nails, through the breather membrane to the roof rafters. Nowadays floor/ceiling insulation is disposed between the floor/ceiling joists as well as between the roof rafters. Roof tiles, whether plain or contoured, are laid on, and nailed to, the tiling battens from the eaves to the ridge in head-to-tail and side-by-side overlapping relationship. If the roof tiles are provided with hanging nibs, these are hooked over the battens during laying. Roof tiling is completed by laying ridge tiles along the ridge where they overlap along their longitudinal edges with the upper course of roof tiles.

It is known to adapt the existing roof space constituting the attic of a residential dwelling, typically used for storage into an additional living space by the process of loft conversion. This may entail roof window conversion in which windows are introduced into the line of the roof, avoiding the need for structural work to the dwelling. Alternatively, this conversion may entail further structural work, for example a dormer conversion which involves extending the existing roof space, a mansard conversion which the party/gable walls are raised or a hip-to-gable conversion in which the gable wall is built up to the ridge line and a new section of roof is built to fill in the gap to create additional space. It will be appreciated that the dormer and hip- to-gable conversion involve substantial structural changes to the roof.

Such renovations create inconvenience for the homeowner or resident during the process of renovation. Further, during the conversion, the work is at the mercy of the elements which may lead to unexpected delays, in turn leading to further possible inconvenience.

It will be further appreciated that since the conversion, assembly, construction, or installation of a roof unit module is by definition occurring at roof level, there will be health and safety risks to be dealt with for the duration of the period of conversion. For example, the necessity for using scaffolding or ladders can only but increase the danger to builders and tilers working on the conversion, assembly, construction or installation.

The potential for such delays, inconveniences and health and safety risks is also relevant to the assembly/construction of a tiled pitched roof module on the tops of the walls of a building in an initial build and reroofing and/or retiling of tiled pitched roof structures.

There is therefore a need to reduce the time spent in performing the loft conversion/assembly/construction/installation of a pitched roof structure on-site, both to reduce the inconvenience to the homeowner or resident during the conversion/assembly/construction/installation and to reduce the inherent health and safety risks to building persons during the conversion, assembly, construction or installation period.

One solution would be to manufacture the elements of the loft conversion or pitched roof structure assembly/construction off-site and transport these elements to the building site of the loft conversion or assembly/construction/installation work. However, a further problem then presents of constructing a suitably robust construction that will survive transport (and meet the associated safety requirements of such transport) and transfer from a transporting vehicle to the upper storey of a building. It will be understood that the stresses during transport will be different to those during transfer and that existing structures may not survive such stresses without significant remedial work being conducted on the pitched roof structure once in place, assuming the pitched roof structure survived the transfer process.

In order to overcome these problems, methods of assembly of a pitched roof construction apparatus as mentioned in the specification of GB 212279.2, and a modular system of pitched roof construction of which a feature is the demountable support beam apparatus mentioned in the specification GB Patent Application 212280.0, have been developed, both of which have advantages of providing solutions to these problems.

To this end, and from a first aspect, the present invention resides in a method of assembly of at least one pitched roof unit module, in which a plurality of truss units each incorporating a floor/ceiling joist and roof rafters fixed to the joists are assembled off-site to form a roof support framework for a roof covering, in which a floor/ceiling is optionally constructed across the floor/ceiling joists of the support framework, in which the at least one pitched roof unit module is provided with a roof covering of tiles which are fixed to the roof rafters of the roof support framework and in which the tiled pitched roof unit module is transported to, and assembled/installed on the tops of the walls of a building at, a building site.

Expressed in another way, the invention resides in a method of assembling, on the walls of a building, a tiled pitched roof unit module having a ridge and two ends that face in opposite directions, which includes lifting the tiled pitched roof unit module from said oppositely facing ends and positioning the tiled pitched roof unit module on the tops of the building walls. Lifting the tiled pitched roof unit module at its ends avoids the need to patch any incomplete sections of underlay and tiling provided by assembling the pitched roof unit structure on the sides of the tiled pitched roof unit module structure. This in turn avoids unnecessary sections of weakness of patched-up underlay in the tiled pitched roof structure once the tiled pitched roof unit module has been assembled. For a particularly stable and balanced lift, the tiled pitched roof unit module may be lifted by attaching three lifting means to the tiled pitched roof unit module for a three-point lift.

If one of the oppositely facing ends is a gable end, the method may include accessing a lifting point at the gable end through an access opening in the ridge. In that case it is preferable that the ridge of the pitched roof unit module includes ridge tiles and that the access opening is created by means of a space for the gable end ridge tile. This provides access to a lifting point inside the gable end of the tiled pitched roof unit module, thereby enabling a tiled pitched roof unit module having a gable-end to be lifted at both its ends.

Alternatively or additionally, at least one of the two oppositely facing ends of the tiled pitched roof unit module may be provided with two spaced apart rafters providing access to a lifting point though the space between the rafters. The tiled pitched roof structure may optionally form one of a plurality of tiled pitched roof modules for positioning one after the other in end-to-end relationship on the tops of the building walls. This enables multiple tiled pitched roof unit modules to be manufactured off-site in a factory or other centralised location for delivery to a building site for assembly onto the tops of the walls of a building. A particularly long or large roof could be conveniently assembled in this way from multiple such pitched roof unit modules.

The method of assembly/construction/installation ideally includes assembling off-site a plurality of tiled pitched roof unit modules structure by providing divisions extending laterally across the roof support framework between sets of the plurality of truss units, thereby to split the support framework into a plurality of tiled pitched roof unit modules. By means of the invention, there is no need to provide scaffolding on site to complete the pitched roof structure.

In order to facilitate transfer of the tiled pitched roof unit modules onto a transporting vehicle and from the vehicle on to the building wall tops, adjacent split modules are spaced apart from each other to enable the accommodation of lifting means.

Such tiled pitched roof unit modules may be positioned in spaced apart end-to-end relationship by means of a least one spacer. By using a spacer to define a gap between adjacent roof modules, an accurate spacing can be conveniently achieved. Alternatively or additionally, the tiled pitched roof unit modules may be positioned and located in aligned spaced apart end-to-end relationship by means of two spacers having complementary interengaging parts. This creates a convenient means of accurately aligning and locating the roof unit modules when positioning a second module next to a previously laid first module on the building wall tops on the building site.

These complementary interengaging parts of the two spacers may be male and female formations, such as a pin engaging in a hole, and may enable the adjacent tiled pitched roof unit modules to be horizontally anchored and/or vertically aligned in a located position. To guard against relative movement of the truss units of the tiled pitched roof unit modules during lifting of the pitched roof unit modules, the roof support framework is strengthened. To this end, the roof rafters of adjacent modules along the divisions are provided with respective battens which extend along the rafters from the eaves to the ridge.

By this means, the plurality of tiled pitched roof unit modules may be readily transported to the building site and transferred in succession onto the building wall tops.

The roof of the assembled tiled pitched roof structure may be completed by laying, at one or both of the said two oppositely facing ends, tiles from the eaves to the ridge. If there is a plurality of tiled pitched roof unit modules, the roof of the tiled pitched roof structure assembled from the tiled pitched roof unit modules with a gap between the ends of the modules may be completed by sealing an underlay, fitting tiles between the spaced apart roof modules in the gap, and interconnecting gutter portions of the roof modules. These completion activities involve minimal work on site so that the majority of the construction of the roof structure may be done off-site in a controlled factory-type environment, free from the complications of adverse weather conditions and other factors, such as health and safety risks.

The invention may also be expressed as a tiled pitched roof structure assembled on the walls of a building, from at least one tiled pitched roof unit module, in accordance with any of the methods defined above.

Whilst the Applicant has found in practice that provision of affixed roof tiles and, optionally, the provision of strengthening the roof rafters adequately secures the plurality of truss units in the roof support framework and guards against relative movement of the truss units during transport, and lifting transfer, the plurality of truss units may be additionally secured to guard against relative movement by providing and installing releasable securing means which will provide additional support to the tiled pitched roof module whilst being transported to the building site and being transferred and to, lifted onto, and installed on, the building wall tops. This releasable securing means advantageously includes a demountable support and lifting beam apparatus.

Accordingly, the method may include providing and installing releasable securing means additionally to secure/strengthen the plurality of trusses in the roof support framework.

Moreover, in cases where, the roof unit module has not been provided with affixed roof tiles, it may be necessary or desirable to secure the plurality of trusses in the support framework during transport and transfer to the building to provide and install releasable securing means in the roof support framework.

Accordingly, from a second aspect, the present invention resides in a modification of the method of the first aspect of the invention defined above, in which tiles are not fixed to the roof rafters of the roof support framework, and in which releasable securing means are provided and installed to secure the plurality of trusses in the support framework.

Preferably the or each of the releasable securing means locates and retains the plurality of truss units with respect to itself.

It should be appreciated that the expressions used in the specification of Patent Application GB 212279.2, namely 'providing and locating the plurality of truss units in the desired configuration' means 'to form a roof support framework' as used herein and namely 'dressing the roof unit' where it includes 'constructing the exterior of the roof unit module' means 'the pitched roof unit is provided with a roof covering of tiles which are fixed to the roof rafters of the support framework'.

Providing the roof covering of tiles which are fixed to the roof rafters of the roof support framework includes providing and fixing a water resistant membrane and battens or lathes for tiling in position and may further include creating an opening through the rafters of the roof unit module and installing a window unit in the opening.

Dressing the roof unit by constructing the interior of the roof unit module or modules may include carrying out any one or more of fitting interior walls, installing wiring, one or more of creation of fitted furniture, such as shelves and/or wardrobes, creation of a stairwell opening, installation of pipes and in the case of a loft conversion connecting power or any other utilities from an existing lower building story to the installed roof unit module or roof unit modules forming the upper story of the building.

The or each roof unit module may be constructed only to the upper storey of the building.

Clearly, in the case of a loft conversion, the tiled pitched roof unit module or plurality of tiled pitched roof unit modules forms the upper story of the building.

Alternatively, the building has an existing roof structure removed to expose the upper storey. Accordingly, the method may include transferring each of the plurality of roof unit modules in turn, or succession, to and fixing it to the upper storey of the building until the plurality of the roof unit modules to form the pitched modular roof structure.

In a modification of the method defined above a dwelling is constructed to an upper storey and a plurality of roof unit modules are assembled in any of the ways provided hereinabove and transferred to and fixed to the dwelling to form the upper story.

After assembly/installation of the or each roof unit module, the releasable securing means, which ideally may be the demountable support and lifting beam apparatus, if provided, may be released and removed from the or each roof unit module or alternatively be left in position.

Therefore, and according to a still further aspect, the present invention resides in a demountable support beam apparatus including a demountable support and lifting beam and a plurality of releasable bracing members.

Preferably, each of the plurality of truss units includes a floor/ceiling joist and one or more of the plurality of bracing members releasably secures the demountable support and lifting beam to one or more of the floor joists of the support framework. Preferably the demountable support beam is extendable. More preferably the demountable support beam comprises an inner member and at least one outer sleeve. For ease and speed of securing, the releasable bracing members preferably incorporate a set of plate members adapted to be releasably secured together and urged toward one another. More preferably the set of plate members when urged towards one another are secured together about the support beam. More preferably, each of the set of plate members comprises at least one upper plate member and at least one lower plate member.

Alternatively, at least one set of plate members comprises two upper plate members and two lower plate members.

Preferably, at least one set of plate members comprises an upper plate and an L- shaped lower plate.

Preferably the set of plate members are releasably secured together by a threaded fastener. More preferably, the threaded fastener comprises a headed bolt and a nut.

According to a yet another aspect, the present invention resides in a modular roof unit provided with a roof support framework including a plurality of truss units disposed in a prearranged relationship with respect to one another, and at least one demountable support and lifting beam apparatus, in which the plurality of releasable bracing members brace the plurality of truss units to maintain the prearranged relationship of the truss units to one another.

Preferably, each of the plurality of truss units includes a floor/ceiling joist and one or more of the plurality of bracing members releasably secures the demountable support beam to one or more of the floor/ceiling joists.

In order that the invention may be more readily understood, some embodiments in accordance therewith will now be described, by way of example only, with reference to the accompanying drawings, in which:- Figures 1 , 2 and 3 are, respectively, a partial perspective view from the front and one end of a pitched roof unit module, a complete side view of the pitched roof unit module of Figure 1 and a perspective view from the front and one end of the pitched roof unit module of Figure 1 , all without a roof covering of roof and ridge tiles and all showing, in a sample location, a releasable securing means including a demountable support and lifting beam;

Figures 1 a, 2a and 3a, are, respectively a partial perspective view from the front and one end of a pitched roof unit module, a complete side view of the pitched roof unit module of Figure 1 and a perspective view from the front and one end of the pitched roof unit module of Figure 1 , all without a roof covering of roof and ridge tiles and without the releasable securing means including a demountable support and lifting beam;

Figure 4 is a perspective view of the demountable support and lifting beam of Figures 1 to 3, and showing two of its cooperating elements;

Figure 5 is a perspective view of a part of the pitched roof unit module of Figures 1 to 3 and showing one embodiment of the releasable securing means of Figures 1 to 4 including bracing members located between adjacent truss units;

Figure 6 is a perspective view of a part of the pitched roof unit module of Figures 1 to 3 and showing another embodiment of the releasable securing means similar to that of Figure 5:

Figure 7 is a perspective end view of a part of the pitched roof unit module of Figures 1 to 3 and showing the releasable securing means of Figures 5 and 6 adjacent an end truss unit;

Figure 8 is a perspective front view of a central pitched roof unit module of a pitched modular roof unit structure;

Figure 9 is a schematic plan view of adjacent roof unit modules making up a pitched modular roof unit for use in a loft conversion; Figure 10 is a perspective view of two partly-shown, adjacent, split tiled pitched roof unit modules of Figures 1 to 7 and to which roof tiles have been fixed, for transfer from an off-site assembly location to a building site and assembly into a tiled pitched roof modular unit structure onto the tops of the walls of a building;

Figure 1 1 is a perspective view from the front and one end of the left-hand as illustrated tiled pitched roof unit module of Figure 10 being lifted into position adjacent a partly-shown divided right-hand, as illustrated tiled pitched roof unit module onto the building wall tops on a building site;

Figure 12 is a side view of the two adjacent tiled pitched roof unit modules of Figure 1 1 being lifted for transfer;

Figure 12a is a detail view of Figure 12 showing the attachment of the lifting means shown in Figure 12;

Figure 13 is partial perspective view of two adjacent tiled pitched roof unit modules which are in process of being completed to form a tiled pitched roof modular unit structure on the building wall tops on a building site;

Figure 14 is perspective view of the two adjacent assembled pitched roof unit modules of Figure 13; and

Figure 15 is a plan view to an enlarged scale of the two adjacent tiled pitched roof modules of Figures 13 and 14.

Figure 16 is a perspective view from one side and one end of a tiled pitched roof unit module in accordance with the invention showing lifting means for lifting the module so it can be laid onto the walls of a building;

Figure 17 is a side view of the tiled pitched roof unit module of Figure 16 showing the roof support framework; Figure 18 is a perspective view from one side and on end of a gable end tiled pitched roof unit module according to the invention showing lifting means for lifting the module so it can be laid onto the walls of a building; Figure 19 is a top plan view of the gable end tiled pitched roof unit module of Figure 18 showing lifting points where the module can be lifted for laying it onto the walls of a building;

Figure 20 is a top plan view of the roof module of Figure 16 showing lifting points where the module can be lifted for laying it onto the walls of a building;

Figure 21 is a side view of one form of lifting means provided as a rope or cable and a foot in engagement with a roof beam for lifting a tiled pitched roof unit module in accordance with the invention;

Figure 22 is a side view of another form of lifting means in engagement with a roof beam for lifting a tiled pitched roof unit module in accordance with the invention;

Figure 23 is a side view of yet another form of lifting means provided as a sling in engagement with a roof beam for lifting a tiled pitched roof unit module in accordance with the invention;

Figure 24 is a perspective view of the gable end pitched roof unit module of Figure 18 positioned on the tops of the walls of a building;

Figure 25 is a perspective view of two complementary spacers for horizontally aligning two adjacent roof modules in accordance with the invention;

Figure 25A is a top plan view of the two complementary spacers of Figure 15 in an interengaged position;

Figure 26 is a perspective view of two complementary spacers for vertically aligning and horizontally anchoring two tiled pitched roof unit modules in accordance with the invention; Figure 26A is a top view plan of the two spacers of Figure 16 in an interengaged position;

Figure 27 is a front view of three tiled pitched roof unit modules positioned on the tops of the walls of a building in accordance with the invention;

Figure 28 is a front view of a tiled pitched roof unit structure assembled from the three tiled pitched roof unit modules of Figure 27 after roof tiles have been laid in the gaps between the adjacent modules;

Figure 29 is perspective view of a building on which the tiled pitched roof unit modules of Figure 27 have been assembled, after roof tiles have been laid in the gaps between the modules; Figure 30 is a perspective view of a further embodiment of a tiled pitched roof unit module in accordance with the invention; and

Figure 31 is a top plan view of the tiled pitched roof unit module of Figure 30. Referring to Figures 1 to 3 and Figures 1 a to 3a of the drawings, there can be seen a pitched roof unit module 1 , in which a plurality of truss units 2, each incorporating a floor/ceiling joist 4 and inclined roof rafters 6 fixed to the joists 4 at their lower ends and joined together at their upper ends at what will ultimately be the ridge of the pitched roof. The truss units 2 together form a roof support framework (skeleton) 3 for a suitable roof covering (not shown) and define a roof space 7, also known as a loft or attic space. A cross member 8 spans the upper region of the internal roof space 7 between the two inclined roof rafters 6 of each truss unit 2. Substantially vertical upright members 10 also join each of the roof rafters to the associated floor/ceiling joist 4. The floor/ceiling joist 4, roof rafters 6, connection member 8 and uprights 10 may be joined (fixed) together in any suitable manner to form each truss unit 2 of the support framework 3.

In an alternative embodiment, the inclined roof rafters 2 and cross member 8 are disposed as before, but the roof rafters are connected to the floor/ceiling joists 4 by additional inclined members located between the base of the vertical members 10 and the inclined roof rafters.

Indeed, the precise construction of the truss units 2 is not a feature of the invention, though it will be appreciated that the truss units define the internal space within the modular roof unit.

The truss units 2 are mounted on a suitable support and arranged in a desired configuration to form the support framework 3 of a pitched modular roof unit. Moreover, the truss units 2 may be arranged in any suitable pattern, for example incorporating one or more portions in which a single truss unit 2 is spaced from neighbouring truss units 2, and/or one or more portions where two or more truss units 2 are located adjacent one another, the outer truss units 2 of such a portion being spaced from neighbouring truss units 2. Inside the roof space 7, the truss units 2 are connected laterally to the roof rafters 6 by cross-members 12 running substantially perpendicular to the truss units 2. Additionally, battons 14 extend laterally of the truss units 2 along the roof rafters outside the roof space 7, to locate the truss units 2 with respect to one another. Further, a transverse beam 16 (Figure 3) connecting the cross members 8 of the truss units 2 inside the roof space 7 may be provided.

Once the support framework 3 of the modular roof unit 1 has been constructed, further assembling/construction actions may be may be commenced.

Such actions may include initial preparations, which by way of example are laying of netting or other retaining material over and between adjacent floor/ceiling joists 4 to receive a suitable insulating material 20. This can then be covered by suitable flooring/ceiling material 22 such as boarding extending across the floor/ceiling joists 4 of the support framework 3. Other such actions which may be carried out before or after the initial preparation include the utilisation of one or more releasable securing means to secure the plurality of truss units in the roof support framework (desired configuration).

An example of a suitable releasable securing means is shown in Figures 1 to 3, in which demountable support beams 30 are be secured in position at each of the sides of the truss units 2. Conveniently, the support beam 30 is located on the floor/ceiling joists 4 of the truss units 2 and against the roof rafters 6 of the truss units 2. This keeps the support beam 30 out of a working area of the pitched modular roof unit 1. Other locations meeting this requirement may also be used, such as atop the floor joists 4 and adjacent outer faces of the vertical members 10 or between these locations (cf Figures 5 and 6). The support beams 30 extend across a single pitched roof unit module of the pitched modular roof unit and are used to prevent/guard against relative movement of the truss units 2 during transfer of the pitched modular roof unit to a transport vehicle at the off-site assembly location, transport to the building site and subsequent transfer to the tops of the walls of the building on the building site for assembly on the building walls. The releasable securing means has as an advantage that it prevents/guards against the relative movement of the truss units 2 and enables the pitched roof unit modules to withstand the stresses of transport and transfer.

The support beam 30 is provided with a plurality of bracing elements to locate and retain each truss unit 2 in relation to the support beam 30.

Turning to the embodiment of Figure 5, a first arrangement is shown illustrating a plurality of truss units 2 and associated bracing elements. In this embodiment, the bracing elements comprise a set of plate members including a lower set of plates 32 arranged laterally of a truss unit floor/ceiling joist 4 extending to each side thereof and an upper set of plates 34 located transversely of the demountable support beam 30. In each of the lower set of plates, the lower plate 32 is provided with four openings 33 through which the shaft 36 of a headed bolt is adapted to extend. Each opening 33 is such that the head (not shown) of the bolt is retained on one side of the lower plate 32. The platform is of sufficient height to enable each of the bolts to be inserted through a respective opening in the lower plates 32 when the lower plates 32 are located substantially beneath the relevant floor/ceiling joist 4.

In an alternative embodiment which is shown in Figure 6, each of the lower set of plates comprises a pair of plates 32' that locates transversely beneath the relevant floor/ceiling joist 4. Each of the lower plates 32' is provided with an opening 35' through which the shaft 36' of a headed bolt is adapted to extend. Each opening 35' is such that the head of the bolt is retained on one side of the lower plate 32'. Each of the upper set of plates 34' comprises a pair of plates extending laterally of the relevant floor/ceiling joist 4 and transversely across the support beam 30. A nut 40' can then be threaded onto each shaft 36' thereby drawing the lower plates 32' upward toward the upper plates 34' to secure the set of plate members together and locate the truss units 2 with respect to the support beam 30.

The bracing members serve to clamp the support beam 30 to the floor joists 4 to prevent/guard against movement of the truss units 2 during transport and transfer of the pitched roof unit module.

In the embodiment of Figure 6, the upper plates 34' are of a suitable size such that a respective inner face of each of the upper plates 34' abuts a face of the roof rafter 6 of the adjacent truss unit 2. When the nuts 40' are tightened securely on the headed bolts the demountable support beam 30 is clamped to the floor joist 4 of the truss uni 2.

Conveniently the openings 33, 35 in the upper and lower plates may comprise an unshown slot to allow for adjustment of the upper and lower plates when securing the support beam 30 in position with respect to the truss units 2.

The support beam 30 is conveniently adjustable in length. In Figure 4, two parts of a support beam 30 are shown. Such a support beam 30 will comprise at least three parts; an inner portion 50 about which a first and second sleeve members 52, 54 are adjustably located (cf Figures 5 and 6). A retaining bolt extends though the first sleeve member 52 to retain it in relation to the inner portion 50 of the support beam 30, for example passing through suitable aligned openings in the inner portion 50 and associated sleeve member 52, 54. Each of the inner portion 50 and first and second sleeve members 52, 54 may conveniently be formed from an O-bar. Each of the inner portion 50 and first and second sleeve members 52, 54 may conveniently be formed of a suitable casting, for example of a steel.

It will be understood that where appropriate more than a single thickness of material may be used to provide one or more of the upper and lower plates 32, 34. Other arrangements of plates may be used to brace the truss units 2 with respect to the support beam 30.

In Figure 7 the bracing members comprise a set of plates made up of a lower L shaped plate 42 extending transversely of the support beam 30 and an upper plate 34. An outer face of the depending member of the L shaped plate 42 abuts a floor/ceiling joist 4 of a truss unit 2 located at one end of the pitched roof unit module. The other member of the L shaped plate 42 is provided with an opening 43 through which the shaft 46 of a headed bolt 43' extends. The upper set of plates 34 also extends transversely of the support beam 30 and is provided with an opening 45. The bracing members are secured together by threading the shaft 46 of the headed bolt 43' through the opening 43 in the lower plate 42 and the openings 45 in the upper set of plates 34, then providing a nut (not shown) on the headed bolt 43' and tightening this nut to the headed bolt. As will be appreciated from the foregoing, the depending member of the L shaped plate provides a brace to enable the releasable securing means to support the roof unit module laterally.

Preferably the depending member of the L shaped plate 42 is provided with openings by which the L shaped plate 42 may be aligned with suitable openings (whether blind or open) in the joist 4 to allow the passage of fastening members such as bolts 58 to further secure the L shaped plate 42 with respect to the joist 4.

In a further embodiment (not shown) sets of plate members other than those at the ends of the releasable securing means may comprise an upper plate 34 and an L- shaped lower plate 42.

Due to the modular nature of the pitched roof structure, the pitched roof unit modules 1 may be constructed off-site at a factory or at warehouse premises. This has as an advantage that the pitched modular roof units 1 may be constructed in an environment protected from adverse weather conditions reducing delays in on-site construction and health and safety risks.

Further work on the pitched roof unit modules of the pitched modular roof unit structure can be conducted prior to the modules leaving the factory. To this end, and referring to Figure 8, a pitched roof modular structure 59 constructed from two pitched roof unit modules 1 is provided with a waterproof/water resistant breather membrane 60 which covers the roof rafters (not visible) of the roof support framework (not visible). Suitable tiling battens or lathes 62 extend laterally across, and are fixed to the roof rafters through the breather membrane 60 in spaced apart relationship up/down the pitched roof modular roof structure. Roof tiles (not shown) can be fixed to the tiling battens 62 and ridge tiles can be fixed along the roof ridge (not visible) when the pitched roof modular structure 59 has been located in position (Figure 8). In the case of a window conversion, space can be left for a suitably sized opening to be created and a prefabricated window unit 66 installed. The breather membrane 60 may be used to cover the entire pitched modular roof unit structure 59 and be split only when separating/dividing the modular roof unit structure 59 into pitched roof unit modules for transport and transfer to a building site. In Figure 8, the bounds of the two pitched modular roof units with each other are marked by adjacent central battens 64 and with their potential neighbours by peripheral battens 44 on opposite sides respectively of the pitched modular roof unit structure 59.

Ideally, as is preferred, the tiles are laid off-site prior to the pitched roof unit modules 1 leaving the factory, to which end the roof tiles are laid on, and fixed to, the tiling battens 62 through the breather membrane 60, in head-to-tail and side-by-side overlapping relationship from the eaves to the ridge and the ridge tiles (not shown) are laid longitudinally along the roof ridge in overlapping relationship along their side edges with the top course of roof tiles (not shown). In this way, the pitched modular roof unit structure 59 is completed off-site and there is no need to provide scaffolding on-site to complete the pitched roof structure.

Building of interior structures, namely the provision of decoration and of utilities, such as internal wiring for lighting and power sockets, for each roof unit module 1 for a loft conversion are designated in this embodiment as internally dressed roof unit modules 70, 72 and 74 can now be conducted and is preferably conducted prior to transport and transfer. For example the internal walls of a modular loft unit may be provided by drywall or plasterboard. Suitable furnishings may also be installed or created such as integral shelf units or wardrobes, as well as openings in the floor for stairwells or stairways as shown in Figure 9. Once the internal decoration of the pitched modular roof unit structure 59 has been completed the individual roof unit modules 1 are ready to be separated and transported for installation In separating the roof unit modules, divisions are provided extending upwardly the modular roof unit between the sets of the plurality of truss units to split the pitched modular roof unit structure 59 into a plurality of pitched roof unit modules 1. These divisions as noted above will extend thorough the breather membrane 60. Further, if arranging for utilities to extend across internal walls of the roof unit modules 70, 72 and 74, suitable connectors will be provided where the divisions are planned.

It will be understood that the support beam 30 and the plurality of bracing elements together form the releasable securing means constituting the demountable support beam and lifting apparatus. The pitched roof unit modules 1 may be lifted from the suitable support by connecting the left and right hand side releasable securing means constituted by the demountable support beam and lifting apparatus to any suitable lifting apparatus and so transferred from the suitable support to a transport vehicle for transport to the site of the loft conversion or assembly/construction of the pitched modular roof unit structure 59 on the building site.

Further, it will be appreciated that the following actions may occur on an existing building in which the roof structure has been removed to expose the underlying structure (whether or not additional structural reinforcement has been conducted) or for a new build which has been built to a corresponding level. For a loft conversion, the term 'floor' joists 4 is relevant whereas for a new build for example the term 'ceiling' joists 4 may be relevant.

On-site the pitched roof unit modules 1 may be lifted from the transport vehicle by connecting the left and right hand side releasable securing means to any suitable lifting apparatus and so be transferred from the transport vehicle to an installation site

Typically, a first end roof unit module 1 is raised into position, for example above a wall beam or plate of the exposed structure and the truss units 2 fixed to the exposed structure in a suitable manner. It will be appreciated that fixing of the roof unit module 1 to the underlying structure may be achieved in any suitable manner. The releasable securing means in the roof unit module 1 can then conveniently be released from the roof unit module and removed. This has as an advantage that the releasable securing means are then free for reuse. In particular, the bracing members in the roof unit module 1 can then be removed from their associated support beam 30 by releasing the nuts 40, 49 from the headed bolts. The support beam 30 can itself then be removed from within the roof unit module 1 , if necessary by further separating the sleeve members 52, 54 from the inner portion 50. The support beam 30 and associated bracing members are then free for reuse.

The L shaped member 42 can also be released if secured by bolts 58 by the removal of these bolts.

Subsequent roof unit modules 1 may then be moved into position, secured into that position and the support beams 30 and associated bracing members removed, finishing with the final roof unit module 1 being transferred to complete the pitched modular roof unit structure and fixing it in position and the releasable securing means being released and removed. In the case of the final roof unit module 1 , it may not be possible easily to remove releasable securing means, i.e. the support beams 30. However, it is envisaged that an opening or window toward the end of the roof unit module 1 can be created to ease removal of the final releasable securing means/ support beam(s) 30. In practice, since the ends of the roof conversion will be covered with brickwork or similar it is envisaged that this opening or window will not create significant additional work on site.

It will be appreciated that where the modular roof unit replaces an existing structure, scheduling the removal of the existing roof and the fitting of the replacement structure will take a relatively small period of time in comparison with known on site construction/conversion without the use of such a modular roof unit creating advantages for the homeowner and those performing the work.

Finally, with respect to the interior of the roof space 7 with loft conversions, since the provision of utilities has been provided for off-site it remains only for the connections to be made to the relevant supplies within the building eg electricity and water. Thereafter, the final steps including installation of sanitary features (if required) to any preinstalled pipework and installation of the staircase from the underlying structure to the roof space 7, (if not already provided for) can be attended to. With respect to the exterior, suitable tiling, shingles or other weatherproofing roofing can now be affixed to the assembled modular roof unit 1.

The embodiments of Figures 10 to 15 differ from those of Figures 1 to 9 in that roof tiles 80 are laid on, and fixed to, the tiling battens 62 which are fixed through the breather membrane 60 to the roof rafters 6 of the plurality of truss units 2 forming the roof support framework 3 of at least two tiled pitched modular roof units 1 to form the tiled pitched modular roof unit structure 59 with roof rafters of all of the modules are covered being covered by the breather membrane 60. The pitched modular roof unit structure 59 is assembled and split into the tiled pitched roof unit modules 1 off-site prior to leaving the factory where they are assembled. The roof tiles 80 are laid in courses from the roof eaves 82 to the roof ridge 84 in head-to-tail and side-by-side overlapping relationship. Ridge tiles 86 are laid longitudinally along the roof ridge 84 in overlapping relationship along their side edges with the top course 87 of the roof tiles 80. As will be appreciated from Figures 10 to 15, the support framework of the tiled pitched modular roof unit structure 59 is split into a plurality of tiled pitched roof unit modules 1 by at least one division extending along the rafters of the support framework 3 between sets of the plurality of truss units 2. The or each division is made by severing the breather membrane and cutting the tiling battens to produce an eaves to ridge gap 88 between the roof rafters 6 of adjacent truss units 2. Expressed another way, the roof tiles 80, breather membrane 60 and tiling battens 62 do not extend laterally across the gap 88 which is free of roof tiles 80, thereby enabling the tiled pitched roof unit modules 1 to be separated from one another as will be apparent from Figures 14 and 15. The roof rafters 6 of adjacent tiled pitched roof unit modules 1 along the gap 88 caused by the or each division are strengthened by providing respective counter battens 90 which are fixed along the adjacent rafters 6 from the roof eaves 82 to the roof ridge 84. And elongate packing elements 91 are fixed to, and extend along, the roof rafters 6 along the gap 88 beneath the respective counter battens 90 from the roof eaves 82 to the roof ridge 84. The provision of the counter battens 90 and packing elements 91 preserves the gap 88 to provide a space to enable the accommodation of lifting means 92 when two adjacent tiled pitched roof unit modules units 1 are assembled together on the building walls at the building site to the form the tiled pitched modular roof unit structure 59. The adjacent split tiled pitched roof unit modules 1 are located and aligned with respect to each other when lifted by the lifting means 92 and assembled adjacent one another by means of inter-engaging male and female elements in the form of locating pins 93 projecting from one of the packing elements engaging in locating pin holes 94 in the packing element of the adjacent pitched roof unit modules unit 1. The strengthening of the split tiled pitched roof unit modules 1 enables them to be lifted readily without the risk of damage to the unit modules 1.

The lifting means 92 includes four hooks 92a, which are cranked so that the hooks can engage with respective end beams 93 of the support framework 3 roof unit modules 1 substantially within the volume of the roof space 7 and in the space created by the gap 88 between the assembled adjacent roof unit modules 1 and then be disengaged from the end beams. The lifting hooks 92a are attached to lifting lines 92b carried by a spreader beam 92c which is in turn connected to cables 92d for a crane (not shown). The shown arrangement of lifting lines 92b and spreader beam 92c may varied so that the lines 92b extend vertically upwards to avoid sideways unsteady movements of the lifting lines when lifting the roof unit modules 1 and lowering into position on the tops of the building walls.

The eaves to ridge gap 88 between the counter battens 90 of adjacent split tiled pitched roof unit modules 1 is sealed by applying a flexible waterproof seal 95 between the counter battens 90 as will be apparent from Figures 14 and 15 and laying an elongate strip 96 of breather membrane over the waterproof seal 95 and tiling battens 62 and from roof eaves to the roof ridge, as shown in Figures 18 and 19. To complete the tiled pitched roof structure 59, the sealed eaves to ridge gap 88 between the counter battens the remainder of the gap 88 left between the roof tiles 80 of the adjacent tiled pitched roof unit modules 1 is covered by laying filler roof tiles 80 (not shown). It will be appreciated that the demountable support and lifting beams 30, and the associated bracing, as shown in Figures 1 , 2, 3 and 4 to 7 need not be used for the tiled pitched roof module units of Figures 11 to 15. Referring now to Figures 16 and 17, there is shown a tiled pitched roof unit module 150 (hereafter a roof unit module 150) having a roof support framework 151 including a plurality of roof rafters 152 joined to and supported on, floor/ceiling joists 156 by means of which the roof unit modules 150 can be laid on the tops of the walls of a building. The roof rafters 152 extend at an angle from the ends of the joists 156 at the eaves 155 up to the ridge 158 of the roof unit module 150 to form the pitch of the roof. Rafter webs 154 extending between roof rafters 152 and the joists 156 support the roof rafters 152 within the volume of the roof unit module 150 inside the internal roof space 7. Hanging beams 160 extend across the roof rafters 152 between the ends of the roof unit module 150, part-way up the rafters 152, and provide additional support to the roof support framework 151. Beneath the roof apex where corresponding left and right rafters 152 meet and are joined together, a ridge beam 162 extends parallel to the hanging beams 160.

The roof unit module 150 is tiled with roof tiles 164 laid in head-to-tail and side-by- side overlapping relationship from the eaves 155 to the ridge 158 on tiling battens 160 which are fixed to the roof rafters 152 though an underlay, such as a breather membrane, (not shown) laid across the tops of the roof rafters 152 below the roof tiles 164. The tiling is completed by laying ridge tiles 166 along the ridge 158 where their side edges overlap the top course of roof tiles 164. On top of the underlay, the tiling battens 160 (Figure 17) are nailed or otherwise fixed to the roof rafters 152 and the roof tiles 164 are laid on the tiling battens 160 starting at the eaves 155 and ending at the ridge 158. On their undersurfaces, the roof tiles 164 may be provided with hanging nibs (not shown) which hook over the tiling battens 160 to support the roof tiles 164 on the roof and are provided with nail holes (not shown) through which the roof tiles 164 are nailed to the roof rafters 152.

As shown in Figure 16, the roof unit module 150 includes two spacers 168 which are fixed to the end joist 156, and which project from the end joist 156 and the volume of the roof unit module 150. These spacers 168 function to space the roof unit module 150 apart from an adjacent second roof unit module 150 (not shown) when these two modules are lifted to assemble them onto the tops of the walls of a building. The spacers 168 provide an accurate, predefined space 169 between the adjacent tiled pitched roof unit modules 150 when they have been assembled onto the building wall tops. If needs be, two further such spacers (not shown) are at the opposite end of the module for spacing it apart from another module on the opposite side. It will be appreciated, therefore, that this roof unit module 150 is suitable for being laid between at least two other roof unit modules 150 of the roof, taking up an inside position along a serious of modules. The roof unit module 150 is lifted at four lifting points in a balanced lifting arrangement to lay it on the walls of a building. As shown in Figure 16, four lifting means, each comprising a rope or cable 170, are used to lift a beam at each end of the roof unit module 150. At a lower end of each rope or cable 170 is a lifting hook 172 in the form of a rigid metal foot which fits snugly around the underside and one side of the end joist 156. When the lifting hook 172 is engaged with the end joist 156, the hook 172 and rope or cable 170 lie within a region outside the volume of the roof module itself, but not projecting from that volume further that the spacers168. As a result, in this engaged configuration it is the spacers 168 that project the furthest from the roof module, not the lifting hook 172.

Roof unit modules 150 for placement at the end of a roof structure are different to the inner roof unit module 150 already described. The main difference is that end roof unit modules 180 are closed at one end to form a gable end, and as such only have one open end with spacers. A gable end tiled pitched roof unit module 180 of this type is shown in Figure 18, and is hereafter referred to as a gable end roof unit module 180. The closed end is finished and sealed as would be the gable end of a traditional roof structure, and there are no spacers provided at that closed end. As shown, the gable end roof unit module 180 has rafters 152, rafter webs 154, end joists 156, hanging beams 160, a ridge beam 162, roof tiles 164 and ridge tiles 166, and a pair of spacers 168 on the inner end joist 156, as would be the case for an inside roof unit module 150.

However, as indicated by arrow 182, the final ridge tile 166 of the gable end roof unit module 180 is missing. A ridge tile 166 can be fitted at this location after the gable end roof unit module 180 has been laid on the walls of a building, but initially the outermost ridge tile is absent from the gable end module 180. This arrangement provides access for the lifting means to engage the outermost end joist 156 by providing an access opening from outside the roof unit module 180 to the inside of the roof unit module 180 at the closed, sealed end of the gable end roof unit module 180. As shown in Figure 18, the rope or cable 170 of a lifting means is fed through the access opening as indicated by the arrow 182 into the inside of the gable end roof unit module 180 so that the back end joist 156 can be engaged by the lifting means. If the lifting hook 172 of the lifting means does not fit through the access opening, this can be attached to the end of the rope or cable 170 once it has been passed through the access opening and into the gable end roof unit module 180. This creates a lifting arrangement in which the closed end of the gable end roof unit module 180 is lifted at only one lifting point, whilst the open end is lifted at two lifting points. Three lifting points result, and three lifting means are used, which are lifted together as by a crane.

Top views of the gable end roof unit module 180 and inside roof unit module 150 are shown in Figures 19 and 20, respectively. For each roof unit module 150, 180, the roof tiles 164, ridge tiles 166 and spacers 168 are visible in this view. The three lifting points of the gable end roof unit module 180 are indicated by arrows 184 in Figure 19, and the four lifting points of the gable end roof unit module 150 are indicated by arrows 186 in Figure 20. It will be readily appreciated from these top views that the precise number of lifting points can be varied, provided that balanced lifting is achieved. For lifting any given roof unit module 150, 180, at least one lifting point at each end is required. If only two lifting points are used (one at each end), at least one of the lifting points should engage the relevant end joist 156 along a sufficient length of the end joist 156 so as to avoid toppling of the roof unit module 150, 180 and provide balanced lifting. For example, the lifting hook 172 of the lifting means could be elongated along the axis of the end joist 156 and suspended in such a way as to ensure a balanced engagement with the end joist 156 to avoid toppling of the roof unit module 150, 180 about its longitudinal axis parallel to the ridge 158. Notwithstanding this freedom in the total number of lifting points, in the case of a gable end roof unit module 180, it will be appreciated that the access opening at the closed end enables access only to a single lifting point at that end. The engagement of a lifting hook 172 of a lifting means with a end joist 156 is shown in an enlarged side view in Figure 21. As indicated above, the lifting hook 172 is shaped to extend under the end joist 156 to support the underside of the end joist 156, and to extend around the far side of the end joist 156 for effecting a grasping engagement with the end joist 156, to extend around, and engage with, the far side of the end joist 156.. This arrangement ensures a secure lift of the considerable weight of the roof unit module 150, 180.

The lifting hook 172 may be replaced any other suitable means such as an eye screw 188 (or bolt) as shown in Figure 22 or a sling 190 as shown in Figure 23. The eye screw 88 is screwed into the beam 56 and a rope or cable 70 is secured to the eye or loop of the eye screw 188. After the roof unit module 150, 180 has been lifted by the end joist 156 the rope or cable 170 is detached from the eye screw 188 and the eye screw 188 is unscrewed from the end joist 156. With the sling, a separate rope or cable 170 is not necessarily required, although it may be that a rope or cable 170 is attached to the sling 190, for example at a higher location such as nearer the attachment point of a crane. The sling 190 loops around the end joist 156 and is strong enough to support the weight of the roof unit module for secure lifting. In addition to the lifting hook 172, eye screw 188 and sling 190 described, any type of lifting means would be suitable provided that it is capable of secure lifting and does not project from the roof module further than the spacers 168.

With at least two lifting means engaged with the roof unit module 150, 180, the roof module 150, 180 is lifted into position just above the tops of the walls of a building and positioned on the walls before being secured in place. A gable end roof unit module 180 that has been positioned on the building wall tops in this way is shown in Figure 24. The spacers 168 which project from the gable end roof unit module 180 can be seen clearly in this figure and it will be appreciated that this spacing function will create a gap between the positioned gable end roof unit module 180 and the next roof unit module along 150 so that the modules 180, 150 are positioned in spaced apart relationship.

A second roof unit module 150 is then lifted at four lifting points as shown in Figure 16 and positioned on the wall tops next to the previously positioned gable end roof unit module 180 so that an end of the second module 150 is flush with the outermost faces of the projecting spacers 168. Since the spacers 168 project further from the gable end module 180 than the lifting means, the gap 1 12 created between the spaced apart roof unit modules 150, 180 is wider than the lifting means. This enables the lifting means to be accommodated between the roof unit modules 150, 180 so that once the second roof unit module 150 has been laid, the lifting means can be detached from the second roof unit module 150 and drawn upwardly out of the gap between the roof unit modules 150.

Alternatively the spacers 168 may be provided on both the first and the second roof unit modules 180, 150 so that when the second roof unit module 150 is in position the outermost projecting faces of the spacers 168 of each roof unit module 150, 180 are flush with each other. In this case, it is the total width of a spacer 168 of the first roof unit module 180 plus the width of a spacer 68 of the second roof unit module 150 that is wider than the lifting means in order to allow the lifting means to be detached and released through the gap between the spaced apart roof unit modules 150, 180.

With reference to Figure 25, the corresponding spacers 168 may also provide an aligning function. In this case the roof unit modules 150, 180 have corresponding spacers 192 and 194 with female and male formations 196 and 198 which interengage to align the roof unit modules 150, 180 correctly on the building wall tops. Once in aligned engagement, the spacers 192, 194 space the modules apart by a distance d which is the sum of their widths, as indicated in Figure 25A. Referring to Figures 26 and 26A, spacers 100 and 102 provide vertical alignment and horizontal anchorage by means of complementary interengaging male and female formations 106 and 104 respectively. To this end, the female formation 104 has a floor 110 with which the male formation 106 abuts when it is lowered into the female formation 104. In this abutment the spacer 102 cannot move further downwards relative to the spacer 100, and the spacers 100, 102 are vertically aligned. Horizontal anchorage is achieved by virtue of the head 107 engaging in a complementary recess 109.

Regardless of the precise arrangement and form of the spacers 168, 192, 194, 100, 102, the roof unit modules 150, 180 of the roof are lifted and positioned in turn until they are disposed in series on the building wall tops. This creates an assembled tiled pitched roof unit module structure as shown in Figure 27 in which adjacent roof unit modules 150, 180 are positioned in spaced apart, end-to-end relationship. As shown, the spacers 168, 192, 194, 100, 102 define the gaps 1 12 between each pair of adjacent roof unit modules 150, 180.

Referring to Figures 27, 28 and 29, the roof is then completed on-site. All that needs to be done is sealing together overlapping edges of underlay from adjacent modules, retiling of the gaps 1 12 between the middle and the end roof unit modules 150, 180 to close the gaps 1 12, connecting gutters at the eaves of the roof unit modules 150, 180, and fitting a final ridge tile 166 to each of the gable ends of the roof structure.

A further embodiment of the invention enables access to the lifting points of a tiled pitched roof unit module 114, such as a tiled pitched roof unit module 114 (hereafter a roof unit module 1 14), without using spacers. At each end of the roof unit module 1 14, each of the outermost rafters 116 is accompanied, on its inner side, by an additional rafter 1 18, as shown in Figures 30 and 31. For each set of rafters, the additional rafter 1 18 lies parallel to and in spaced apart relationship with the outermost rafter 116 to define a gap 120 between the rafters 1 16, 1 18 for accessing a lifting point of the roof unit module 1 14. A roof unit module 1 14 can be lifted onto the walls of a building and positioned in abutment with a previously laid roof unit module 114. Alternatively, a roof unit module 1 14 an entire tiled roof unit module structure having sets of outermost and additional rafters at its ends could be assembled and lifted onto the walls of a building in this way. In either case, once the roof unit module 114 or whole tiled roof has been laid on the walls of a building, the tiling can be completed by extending it across the rafter pairs.

It will be appreciated by a person skilled in the art that the invention could be modified to take various alternative forms to those described herein, without departing from the scope of the appended claims. Such alternative forms may, for example, include a combination of the above-described embodiments, such as a tiled pitched roof module having a spacer at one end and a set of outermost and additional rafters at the other, or a tiled pitched roof module having a gable end at one end and a set of outermost and additional rafters at the other. It should be appreciated that various modifications may be made to the inventions described herein without departing from the scope of the appended claims.

Claims

1. A method of assembly of at least one tiled pitched roof unit module, in which a plurality of truss units each incorporating a floor/ceiling joist and roof rafters fixed to the joists are assembled off-site to form a support framework for a roof covering, in which a floor/ceiling is optionally constructed across the floor/ceiling joists of the support framework, and in which the at least one tiled pitched roof unit module is provided with a roof covering of tiles which are fixed to the roof rafters of the roof support framework and in which the tiled pitched roof unit module is transported to, and assembled/installed on the tops of the walls of a building at, a building site.

2. A method of assembling, on the walls of a building, a tiled pitched roof unit module having a ridge and two ends that face in opposite directions, which includes lifting the tiled pitched roof unit module from said oppositely facing ends and positioning the tiled pitched roof unit module on the tops of the building walls.

3. A method as claimed in Claim 2, in which the tiled pitched roof unit module is lifted at its ends by attaching three lifting means to the tiled pitched roof unit module for a three-point lift.

4. A method as claimed in Claim 3, in which one of the oppositely facing ends of the tiled pitched roof unit module is a gable end, and including accessing a lifting point at the gable end through an access opening in the ridge.

5. A method as claimed in Claim 4, in which the tiled pitched roof unit module has ridge tiles and in which the access opening is created by means of a space normally occupied by the gable end ridge tile.

6. A method as claimed in Claim 4 or Claim 5, in which the tiled pitched roof unit module has ridge tiles and in which the access opening is created by removing the gable end ridge tile.

7. A method as claimed in any of Claims 3 to 6, in which at least one of the two oppositely facing ends of the tiled pitched roof unit module is provided with two spaced apart rafters providing access to a lifting point though the space between the rafters.

8. A method as claimed in any of Claims 1 to 7, in which the tiled pitched roof unit module has a water resistant breather membrane fixed to the roof rafters of the support framework, tiling battens are fixed through the breather membrane to the roof rafters and tiles are fixed to the tiling battens.

9. A method as claimed in any of Claims 1 to 8, including providing off-site at least one division extending laterally across the support framework between sets of the plurality of truss units, thereby to split the support framework into a plurality of tiled pitched roof unit modules.

10. A method as claimed in Claim 9, including spacing adjacent split tiled pitched roof unit modules apart from each other to enable the accommodation of lifting means to enable the transfer of the plurality of tiled pitched roof unit modules to the building wall tops on-site.

1 1. A method as claimed in Claim 9 or Claim 10, in which the roof tiles, tiling battens and breather membrane do not extend laterally across the at least one division forming an eaves to ridge gap therebetween.

12. A method as claimed in any of Claims 9 to 11 , in which the adjacent split tiled pitched roof unit modules are located and aligned with respect to each other.

13. A method as claimed in any of Claims 9 to 12, in which adjacent tiled pitched roof unit modules are positioned in spaced apart end-to-end relationship by means of a least one spacer.

14. A method as claimed in Claim 13, in which the tiled pitched roof unit modules are positioned and located in aligned spaced apart end-to-end relationship by means of two spacers having complementary interengaging parts.

15. A method as claimed in Claim 14, in which the complementary interengaging parts of the two spacers are male and female formations, such as a pin engaging in a hole,

16. A method as claimed in Claim 14 or Claim 15, in which the complementary interengaging parts of the two spacers enable the adjacent tiled pitched roof unit modules to be horizontally anchored and/or vertically aligned in a located position.

17. A method as claimed in any of Claims 9 to 16, in which the support framework adjacent the at least one division is strengthened.

18. A method as claimed in any of Claims 9 to 17, in which adjacent split tiled pitched roof unit modules are strengthened along the at least one division.

19. A method as claimed in Claim 18, in which the roof rafters of adjacent modules along the at least one division are strengthened by providing respective counter battens which extend along the rafters from the roof eaves to the roof ridge.

20. A method as claimed in any of Claims 9 to 19, in which elongate packing elements are fixed to, and extend along, the roof rafters of the at least one division and beneath the respective counter battens from the roof eaves to the roof ridge.

21. A method as claimed in Claim 12, or any claim dependent thereon, in which the location and alignment is carried out by means of inter-engaging male and female elements of the adjacent elongate packing elements.

22. A method as claimed in Claim 9, or any claim dependent thereon, including sealing of the eaves to ridge gap between the tiling battens and breather membrane of adjacent split tiled pitched roof unit modules.

23. A method as claimed in Claim 22, in which the sealing of the eaves to ridge gap includes applying a waterproof seal and laying an elongate strip of breather membrane over the tiling battens and waterproof seal from roof eaves to the roof ridge.

24. A method as claimed in Claim 23, in which the eaves to ridge gap between the roof tiles of the adjacent split tiled pitched roof unit modules is closed by the laying of roof tiles to complete the tiled pitched roof structure.

25. A method as claimed in any of Claims 1 to 24, and enabling installation of a tiled pitched roof structure on-site from a plurality of tiled pitched roof unit modules assembled/constructed off-site and completion of a tiled pitched roof structure without the use of scaffolding.

26. A method as claimed in any of Claims 1 to 25, and including providing and installing releasable securing means to secure the plurality of trusses in the support framework additionally to that provided by the tiles during transport of the or each tiled pitched roof module to, and installation on the building wall tops at, the building site.

27. A modification of the method as claimed in any of Claims 1 to 26, in which the support framework is without tiles and in which releasable securing means is installed to secure the plurality of trusses in the support framework during transfer of the at least one pitched roof module to, and assembly/installation on the building wall tops at, the building site.

28. A method as claimed in Claim 26 or Claim 27, in which the or each of the releasable securing means locates and retains the plurality of truss units of the support frame with respect to itself.

29. A method as claimed in any of Claims 26 to 28, in which after assembly/installation of the or each roof unit module, the releasable securing means is released and removed from the or each roof unit module.

30. A method as claimed in any of Claims 26 to 28, in which after assembly/installation of the or each roof unit module, the releasable securing means is left in position.

31. A method as claimed in any of claims 1 to 30, including creating an opening through the rafters of the or each roof unit module and installing a window unit in the opening.

32. A method as claimed in any of claims 1 to 31 , in which the or each roof unit module is constructed only to the upper storey of the building.

33. A method as claimed in any of claims 1 to 32, in which the building has an existing roof structure removed to expose the upper storey.

34. A method as claimed in any of Claims 1 to 33, for a loft conversion, in which the at least one pitched roof unit module forms the upper story of the building.

35. A method as claimed in any of Claims 1 to 34, including carrying out off-site any one or more of fitting interior walls, installing wiring, one or more of creation of fitted furniture, such as shelves and/or wardrobes, creation of a stairwell opening, installation of pipes and in the case of a loft conversion connecting power or any other utilities from an existing lower building story to the installed at least one roof unit modules forming the upper story of the building.

36. A method as claimed in any of Claims 1 to 35, including transferring each of aplurality of roof unit modules in turn, or in succession, to and fixing it to the upper storey of the building until the plurality of the roof unit modules form the pitched modular roof structure.

37. A method as claimed in Claims 26 or Claim 27, or any claim dependent on either of these claims, in which the or each of the releasable securing means includes a demountable support and lifting beam apparatus.

38. A method as claimed in Claim 37, in which the demountable support and lifting beam apparatus includes a demountable support and lifting beam and a plurality of releasable bracing members.

39. A method of assembly of at least one pitched roof unit module as claimed in Claim 1 or Claim 2 and substantially as hereinbefore described.

40. A method of assembly of at least one pitched roof unit module as claimed in Claim 1 or Claim 2 and substantially as hereinbefore described with reference to any of Figures 1 to 31 of the accompanying drawings.

41. A tiled pitched modular roof unit structure including at least one pitched roof unit module assembled/constructed/installed by the method of any of claims 1 to 39.

42. A demountable support and lifting beam apparatus including a demountable support and lifting beam and a plurality of releasable bracing members.

43. A demountable support and lifting beam apparatus as claimed in Claim 37, Claim 38 or Claim 42, in which the demountable support and lifting beam is extendable.

44. A demountable support and lifting beam apparatus as claimed in Claim 42 or Claim 43, in which the demountable support and lifting beam comprises an inner member and at least one outer sleeve.

45. A demountable support and lifting beam apparatus as claimed in any of Claims 42 to 44, in which the releasable bracing members comprise a set of plate members adapted to be releasably secured together and urged toward one another.

46. A demountable support and lifting beam apparatus as claimed in Claim 45, in which the set of plate members when urged towards one another are secured together about the support beam.

47. A demountable support and lifting beam apparatus as claimed in Claim 45 or Claim 46, in which each of the set of plate members comprises at least one upper plate member and at least one lower plate member.

48. A demountable support and lifting beam apparatus as claimed in any of Claims 45 to 47, in which at least one set of plate members comprises two upper plate members and two lower plate members.

49. A demountable support and lifting beam apparatus as claimed in any of Claims 45 to 47, in which at least one set of plate members comprises an upper plate and an L- shaped lower plate.

50. A demountable support and lifting beam apparatus as claimed in any of Claims 45 to 49, in which the set of plate members are releasably secured together by a threaded fastener.

51. A demountable support beam apparatus as claimed in Claim 50, in which the threaded fastener comprises a headed bolt and a nut.

52. A demountable support and lifting beam apparatus substantially as hereinbefore described with reference to and as illustrated in Figures 1 to 7 of the accompanying drawings.

53. A modular roof unit comprises a support framework including a plurality of truss units having a prearranged relationship to one another, and at least one demountable support and lifting beam apparatus in accordance with any of Claims 42 to 52, in which the plurality of releasable bracing members brace the plurality of truss units of the support framework to maintain the prearranged relationship of the truss units to one another.

54. A modular roof unit as claimed in Claim 53, in which each of the plurality of truss units includes a floor/ceiling joist and one or more of the plurality of bracing members releasably secures the demountable support and lifting beam to one or more of the joists.