WO2001011161A1

WO2001011161A1 - Self supporting composite roofing panel

Info

Publication number: WO2001011161A1
Application number: PCT/AU1999/000644
Authority: WO
Inventors: Richard George EAST
Original assignee: East Richard
Priority date: 1999-08-10
Filing date: 1999-08-10
Publication date: 2001-02-15
Also published as: AU5271699A

Abstract

A roofing system includes a roof element (12) comprises upper (64) and lower (66) layers of a rigid strong sheet roofing material and includes a layer of insulating material sandwiched between the two layers. In lateral cross section, the element defines two generally planar beam sections (56) disposed either side of an integral central lower roof portion (62). The beam elements connect that central lower roof portion to two integral generally planar upper roof portions (52) extending along and defining each longitudinal edge of the roof element. The longitudinal edges of the roof element define connection means (72) for joining one such roof element to an adjacent roof element such that the join is located at the highest part of the joined elements in cross section.

Description

Title of the Invention

SELF SUPPORTING COMPOSITE ROOFING PANEL Field of the Invention

This invention relates to improvements in the construction of buildings generally, with particular reference to the provision of roofing/shelter elements. Background of the Invention

Although many different methods of construction have been incorporated in buildings, the basic design principals generally employed have not changed significantly over many hundreds of years. Historically, roofs have comprised a framework of rafters, purlins, beams and trusses which are arranged to support a covering or roofing material which currently and in the past have included such diverse materials as stone, thatch, slate, tiles, and metal sheeting in various forms and profiles. The present invention aims to provide improvements and advances in the construction of buildings which enables buildings to be constructed more quickly and more cheaply than traditional systems.

In one aspect, the invention has evolved from a desire on the part of the inventor to provide a system of construction that would enable construction times for simple buildings to be reduced to hours rather than weeks, to negate the need for skilled site labour or outmoded methods of construction, to reduce the use of natural materials and, if required, to enable the construction materials to be quickly recoverable for use elsewhere. Summary of the Invention In its broadest first aspect, the present invention relates to a roof element comprising upper and lower layers of a rigid strong sheet roofing material and including a layer of insulating material sandwiched between the two layers, wherein the roof element in lateral cross section is shaped to define two generally planar beam sections disposed either side of an integral central lower roof portion and wherein the beam elements connect that central lower roof portion to two integral generally planar upper roof portions extending along and defining each longitudinal edge of the roof element, the beam elements providing resistance to bending of the layer along the length of the element and providing rigidity to the element sufficient to make the roof element self supporting over a length of at least 5 m and wherein the longitudinal edges of the roof element define connection means for joining one such roof element to an adjacent roof element, the arrangement being such that with reference to a given horizontally oriented datum line extending along the top of the element when two such elements are joined along their longitudinal side edges, the join is located at the highest part of the joined elements.

Thus the present invention provides a roof element which is shaped so that it can function as both the supporting element for the roof covering, ie, the rafter or the girt beam on a traditional roof, and insulation, as well as the roof covering material. The beam sections of the roof element could, but need not be, vertical and typically may define an angle of about 60-70° with the plane of the roof element.

The roof element of the present invention eliminates the need for bracing and can also eliminate the need for a ceiling since there is no roof supporting structure which needs to be hidden and because the element itself includes insulation.

The upper layer and a lower layer may comprise steel or aluminium sheeting. The insulating material, may be foam. A styrene based foam is preferred for economic reasons and because it will not give off toxic fumes in the event of a fire.

The roof element of the present invention, is suited for most types of buildings, including industrial buildings, and may be utilised for either a flat roof or a sloped roof. By eliminating the need for purlins, bracing and a ceiling, the roofing element can cut out a significant proportion of the costs and times involved in assembling a roof. The upper and lower layers of the roof element can be made from formed sheets of steel, although other metals such as zinc and aluminium could be used instead of either of the steel sheets. Typically, the sheets will be coated by an anti-corrosive, paint finish or the like, for durability. In a preferred embodiment, the element is symmetrical about its longitudinal central axis, and with reference to the given horizontally oriented datum line, each upper roof portion is oriented at an angle of approximately 5° to the horizontal line, the beam sections are oriented at 60 to 70° to the datum line, and a further portion where the angle of the element is approximately 5° below horizontal which further portion extends as far as the central longitudinal axis of the roofing element, the other half of the cross section being a mirror image about the central axis.

Typically, along each lateral edge the upper and lower sheets are folded over to define means for connecting juxtaposed roof elements together.

In particular, along each lateral edge the sheet bends upwards and then back towards the central axis generally parallel to the upper surface of the upper sheet for a few cm. The lower sheet depends away from the plane of the lower sheet and generally perpendicular thereto. When two roof elements are then placed side by side a generally C shaped flashing/securing strip can be used to connect the two top sheets together and provide anchorage of the element. A series of bolts or similar passing through holes in the depending parts lower sheets may be used to connect the bottom sheets together and, optionally, to an anchorage device which may incorporate and over-centre cam. The extreme lateral edges ends of each assembly of juxtaposed roofing elements may be bolted to a wall support cradle or by cam hold down to a wall or other support member.

The invention also provides a support cradle which is a generally planar whose edges define flanges which are generally perpendicular to the plane of the cradle and which may optionally include ventilation louvres. The cradle may be formed from sheet metal. Alternatively, it may be moulded from a plastics material or similar. The cradle support defines a flat base and perpendicular sides and an upper surface which is configured to mate with the lower surface of a roofing element. The cradle element may be fitted under the supporting ends of the roofing element at the apex of the roof or eaves thereof for closing the gap between the roofing element and the wall or the like on which the roofing element sits. In areas subject to extreme weather conditions, two cradle supports can be provided.

The cradle support may also be used in an inverted configuration with the flat base facing upwards. When in that configuration, it is possible for the cradle support to be placed over the join between two juxtaposed roof elements. If the cradle support is made without louvres the cradle supports can in that configuration be used to turn the roof into a series of reservoirs or water traps which, during storms, would slow the rate of run off from the roof and relieve pressure on storm drainage systems.

The inverted cradle on the ridge of the roof can also be used to provide ventilation at that location. Ventilation may be provided by a series of through holes in the roof element, preferably in the lateral end portions adjacent to the lateral edges of the roofing element. Covers/ ducts may be provided and disposed above those through apertures with ventilation being provided by natural convection of air through the panels and along the ducts to the apex of the roof particularly if the roof is angled.

In a preferred embodiment, the covers forming the ducts may be made of polycarbonate as it would also allow natural light into the building through the roof.

To gain full advantage of the system the preferred construction of the supporting structure is of panelized form based on a modular dimensioning configuration.

In a preferred embodiment this panelized form of construction commences at a half module location necessitating the provisions of formed corner panels. This form of construction enables wall/panel support to be provided on initial set up and connection of the upper wall plates. Advantages of the Invention

The invention may utilise commonly available materials manufactured from materials and substances abundantly available in many parts of the world with such materials providing desirable life spans given acceptable environmental conditions.

The invention provides complete compatibility of material finishes to all surfaces exposed to electrolytic action or contaminants. The invention provides a near continuous layer of upper surface sheeting without penetrations other than those for natural lighting and ventilation if provided. Any such openings are contained in a covered plenum space if provided.

Ventilation, by venturi action, and natural lighting can be provided simply and by non-mechanical means.

The invention utilises a longitudinal jointing procedure with the joint being seated at the highest point of the panel profile. Any loading imposed on the panel would result in compression at this location.

The weather capping/locking mould anchors the upper sheeting layer should any de-lamination of that sheet from the insulating material occur.

Securing of the roofing panels is individually effected and with a simple cam operated securing device or hold down provided at each end of the panels at the top and at the upper profile location. Alternatively, securing can be effected at these locations by way of traditional bolting methods coupled with the metal cradles.

The system of securing and sealing at the longitudinal point allows the removal and replacement of individual panels without effecting the adjoining panels should any such action become necessary.

The invention provides for stormwater retention and limiting dispersal by way of inverted non-ventilated "cradles" fixed to the upper roof sheeting. This method of stormwater retention and disposal is to become a requirement for single residential developments generally in Australia. Similar treatment has been a requirement for some years on most other types of new development. The invention being manufactured under controlled industrial processes results in uniform standards of construction and finish with the resultant reduction of "human error" situations occurring resulting in predictable and sustainable quality control in the panels being achievable. The invention provides improvements in quality and construction which enables roofs and subsequently buildings to be constructed considerably quicker and more economically than traditional roofing systems.

The invention for buildings of limited magnitude, comprises low depth to span criteria resulting in a more aesthetically pleasing appearance to such buildings resultant from fascia and other concealing/finishing elements being minimised in height and bulk.

The invention will enable the construction of smaller scale buildings to be undertaken by persons of limited skills following the provision of a base support slab or structural flooring system. Site assembly equipment and tools and personal equipment required for construction is limited to a hammer.

A specific embodiment of the invention will now be described by way of example only and with reference to the accompanying drawings in which; Figure 01 is an isometric drawing of part of a roof embodying aspects of the present invention;

Figure 02 is a transverse sectional view through a non-ventilated roof or part of a roof along an axis parallel to the apex of the roof;

Figure 02A is a similar view to Figure 2 but the section passes through apertures in the roof which define vents; Figure 03 is a longitudinal section along line 03 shown in Figure 2A. Figure 04 is a section through two elements joined side by side with the right hand element also being joined to a fascia which also shows the positioning of ventilation hole covers;

Figure 04a is a similar view to that of Figure 4a but in which the roofing elements are also connected to an anchorage device;

Figure 04b is a large view of fixing details where two roofing elements are joined side by side;

Figure 04c shows the connection of lateral end of a roofing element to a wall or fascia of a roof; Figure 04d is a longitudinal section along line 0X0 shown in Figure 04 illustrates an over-centre cam hold down device for securing the roof to the building;

Figure 04e is a longitudinal section along line 04E shown in /Figure 04; Figure 04f is a longitudinal section along line 04F of Figure 04 and illustrates a gutter mounting;

Figure 05 shows a stylised view of the connection element shown in Figure Aa;

Figure 06 is an end view of a cradle support; figure 01 is a perspective view of the cradle support of figure 6; Figure 0S> is an exploded view of the roof;

Figure 09 is a template for a sleeve;

Figure 10 is a perspective view of a plug being fitted into a sleeve; and Figure 11 is a section through a plug and sleeve. Detailed Description of a Preferred Embodiment Referring to the drawings, Figure 01 shows a pitched roof 10 incorporating roofing elements and other features of the present invention.

A number of features can be seen in the roof. The roof includes a plurality of elongate roofing elements 12 which are juxtaposed in side by side relation and joined together by fixing means which will be described in detail below. There are four such roofing elements making up each half of the roof extending from the eaves 14 to the apex 16. At the left hand side of the roof, as oriented in Figure 1, the roof is finished by a barge board 12>. A gutter fascia 20 of which on a short section is illustrated extends along the lower part of the roof. Some of the roofing elements 12 also define a series of through apertures 22, above which is located a cover 24, to prevent the ingress of rain or the like into the building through the apertures. The cover defines a duct along which air can pass and which creates natural convection in the building with hot air passing up through the apertures 22 and up through the cover 24 to the apex of the roof which would also act to draw air through the lower end 26 of the duct to create a natural draft venturi and help suck hotter air out of the building.

Also illustrated in figure 01 are a series of cradle supports 30 which will be described in more detail below, which are disposed in one orientation, under the eaves and which are adapted to mate with the underneath of the roof elements to close the gap between the roof element and the upper end of the wall 31 and which are used in an upside down configuration (see element 32) where they may act as a support a central duct 34 passing along the apex of the roof and provide exhaust ventilation to that section of the roof. Figures 02 and 02a show sections through the roofing components downhill of a stop end as would be found on a pitched or sloping roof. Figure 02 details a non-ventilated roof while 02a indicates ventilation/light openings 22 and weather covers 24. Figure 03 details a longitudinal section through such openings/covers. Although indicated as a level or flat roof the same detail would be applicable to a pitched or sloping roof.

The system including the supporting structure and comprising a panelised form of construction, ideally, is suited to and based on modular planning. In this connection that dimension indicated as D1 on Figure 02 and Figure 04 will be 900 mm however this dimension is flexible and could be increased or decreased if required. A maximum dimension of 1200 mm would however enable more efficient manufacture and handling to be effected.

With reference to Figure 04 it can be seen that, with reference to a given horizontal^ oriented datum line 50 each roofing element defines a first gently angled portion 52 oriented at approximately 5° to the horizontal which extends to a point 54 where the angle is of the portion 56 of the roof element becomes much steeper, approximately <bO° to 10° to the horizontal before another step 53 is reached where the angle of portion <δO of the element against changes to approximately 5° to the horizontal until it reaches the central longitudinal axis 62. The other half of the element is a mirror of the first half along that axis.

Each roofing element comprises an upper sheet 64 and lower parallel <δ<δ sheet of formed or profiled metal between which a layer of styrene or similar foam is glued to the upper and lower sheets and typically may be 50- 100 mm thick depending on the thermal and or structural requirements of the element. The lateral ends of the roofing elements are finished in a particular fashion as is best illustrated in Figures 04A to 04C. The edge part 65 of the upper sheet of metal is bent upwardly and then back towards the roofing element along a line parallel to the upper surface of the roofing element. The edge 70 of the metal sheet which forms the lower surface of the roofing element is bent downwards. The right hand side of each roofing element is a mirror of the left hand side. Each roofing element is closed by a formed strip of metal 72 which mates with and is attached to the edge piece 63 of the upper sheet and the depending edge piece 70 of the lower sheet. The step 72 closes the element, precents damage to the foam and provides the means for locking the elements together and securing them to the supporting building structure as will be described in more detail below.

Figure 04a shows the first type of fixing means where the lateral edges of the roofing elements are joined together at the point of structural securing by means of a continuous longitudinal weather capping/locking mould 74 which is generaly a C shape in section which joins the two bent over portions of the upper sheet 63 and strip 72 of two juxtaposed roofing elements together. The bottom and securing or hold down method at this point comprises the insertion of a metal stud profiled to secure the upper ends of cam/overcentre hold down device 120 anchored to the structural components supporting the roof elements. Figure 04b shows an arrangement where the same capping/locking mould 74 is provided to the top of the assembly while the bottom projections 10 are secured by means of expanding spring studs, pins or nuts and bolts if required. Figure 04c shows means of attaching an edge of a roofing element to a fascia panel 13 or a wall. The upper end of the fascia panel defines an element which extends upwards and back along the top of the panel so that the weather capping/locking mould 74 can be used to secure the upper surface of the roofing element to the upper surface of the fascia panel. The fascia panel also defines a circular hole 90 behind which is an aperture force driven into tre shape of a truncated cone into the foam layer.

The widest part of the cone is a slighty greater diameter than the hole in the steel plate. A plug 100 best seen in Figure 10 defines a distal end portion 102 which is also in the shape of a truncated cone, a narrower cylindrical middle portion 104 and a wider cylindrical end portion 106 so that the plug can be push fitted into the conical hole in the fascia panel. The plus 100 is typically made of nylon or plastic material and around the outside of the plug there is a sleeve 110 made from an X shaped piece of steel (Fig. 9), which is pressed in shape best seen in Figure 10 and 11. The sleeve takes the load on the join between the fascia and roof element and prevents damage to the roof element. Thus no stress is caused to the nylon/plastic and the plug is prevented from being damaged nylon/plastic being a relativeh soft material, which could be damaged if stressed.

Figures 6, 7 and 3 show the cradle support 30 comprising a generally planar sheet of metal or moulded plastic, the edges of which are bent or moulded to define flanges 122 which are generally perpendicular to the plane of the cradle and which may optionally include ventilation louvres or openings 124. The cradle support defines a flat base 126 and perpendicular sides 123, 130 and an upper surface 132 which is configured to mate with the lower surface of a roofing element. The cradle element may be fitted under the extreme ends of the roofing element at the apex of the roof or eaves thereof for closing the gap between the roofing element and the wall or the like on which the roofing element sits.

The cradle support may also be used in an inverted configuration with the flat base facing upwards. When in that configuration, it is possible for the cradle support to be placed over the join between two juxtaposed roof elements. If the support is made without louvres the cradle supports can in that configuration be used to turn the roof into a series of reservoirs or water traps which, would slow the rate of run off from the roof and relieve pressure on storm drains where such conditions are required or desirable.

The covers for the ventilation apertures 24 may be made from metal such sheeting or from polycarbonate if it is desired to let sunlight through the apertures in the roof.

Although the described roofing element is made of steel filled with a styrene foam, it would be possible to replace the steel with any other strong sheet material which can be formed into the correct shape such as zinc or aluminium and the surface may be coated with an anti corrosive or paint or the like to protect the external base material from corrosion and to provide a more satisfactory bonding of adhesives between the metal and foam internally.

The styrene foam may be replaced by any plastic foam or suitable insulation material which has sufficient form and durability and adhesive qualities.

The roof can be used on either pitched, sloping form or flat roofs regardless of building types or usage. It can be utilised for larger industrial type buildings as indicated in Figure. The system eliminates the need for purlins, beams for bracing and the fitting a ceiling in instance of a saving of over 90% of the time spent fixing a roof is possible.

Where the system is utilised on roofs not requiring the provision of a ridge capping 13 or similar over flashings all fitting, securing and finishing can be carried out from under or outside this roof negating the need for "on roof worker a situation that under current legislation requires the use of expensive balustrades, handrails and the provision of safety harnesses to provide safety to all personnel engaged on roof construction work where heights from the ground exceed 3 metres.

It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the invention as shown in the specific embodiments without departing from the spirit or scope of the invention as broadhy described. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.

Figures 12 and 13 show the construction panel configuration in wall (Fig. 12) and roof elements (Fig. 13).

The walling system is commenced using corner panels 136 to support the upper wall structural plate and enabling intermediate panels X51/1 >S> to be installed prior to horizontal securing of the panels by means of anchor bolts at panel junctions 140.

Figure 13 indicates the roof panel layout relative to the supporting wall structure with securing devices 142 between the upper wall structural plate and the underside of the roof panels.

Claims

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:-

1. A roof element comprising upper and lower layers of a rigid strong sheet roofing material and including a layer of insulating material sandwiched between the two layers, wherein the roof element in lateral cross section is shaped to define two generaly planar beam sections disposed either side of an integral central lower roof portion and wherein the beam elements connect that central lower roof portion to two integral generally planar upper roof portions extending along and defining each longitudinal edge of the roof element, the beam elements providing resistance to bending of the layer along the length of the element and providing rigidity to the element sufficient to make the roof element self supporting over a length of at least 5 m and wherein the longitudinal edges of the roof element define connection means for joining one such roof element to an adjacent roof element, the arrangement being such that with reference to a given horizontally oriented datum line extending along the top of the element when two such elements are joined along their longitudinal side edges, the join is located at the highest part of the joined elements.

2. A roof element as claimed in claim 1, wherein the beam sections of the roof element define an angle of between 90 and 120° with the respect to the horizontally oriented datum line.

3. A roof element as claimed in claim 1 or claim 2 wherein the upper and lower layers are formed from stainless steel or high tensile steel.

4. A roof element as claimed in any preceding claim wherein the element is symmetrical about its longitudinal central axis, and with reference to the given horizontally oriented datum line, each upper roof portion is oriented at an angle of approximately 5° to the horizontal line, the beam sections are oriented at <δO to 10° to the datum line, and a further portion where the angle of the element is approximately 5° below horizontal which further portion extends as far as the central longitudinal axis of the roofing element, the other half of the cross section being a mirror image about the central axis.

5. A roof element as claimed in any preceding claim wherein along each lateral edge, the upper and lower layers are bent to define means for connecting juxtaposed roof elements together.

6. A roof element as claimed in any preceding claim wherein along each lateral edge the upper sheet bends upwards and then back towards the central axis generally parallel to the upper surface of the upper sheet wherein the lower sheet depends away from the plane of the lower sheet and generally perpendicular thereto and so that when two roof elements are placed side by side a generally C shaped clip can be used to connect the two top sheets together and a series of bolts passing through holes in the depending parts lower sheets may be used to connect the bottom sheets together and, optional^/, to an anchorage device. 3. A roofing system comprising a roof element as claimed in any preceding claim and a cradle support having a generally flat base substantially perpendicular sides and an upper surface which is configured to mate with the lower surface of the roofing element the arrangement being such that the cradle support may be filled under the supporting ends of the roofing element for closing the gap between the roofing element and a wall. 9. A vertically supporting structural system is provided by means of a "half module" panel configuration whereby corner structural support elements are placed initially to provide lateral and horizontal support of the structural upper plate supporting and anchoring the roofing components.