Building Panel
Field of the Invention:
This invention relates to a building panel and a method of constructing a building using such panels.
Background of the Invention:
In one of the traditional methods of building construction the primary load-bearing components of the building structure (comprising floors, beams and columns) is first established as a load-bearing "skeleton", after which block-work and/or brickwork is laid around the skeleton so constructed. However, since this construction method requires the laying of individual bricks and/or blocks around the building it is time-consuming, labour- intensive and expensive. Further, since the un-set mortar between bricks or blocks can be washed away if exposed to rain whilst the bricks are being laid, this construction method is also weather-dependent.
In another traditional method of building construction, the brickwork (or the brickwork and the blockwork) is replaced by stud frame Glass Reinforced Cement (GRC) cladding which is attached to the load-bearing skeleton of the building. Fig. 1 A is a transverse section of a wall in which both the brickwork and blockwork have been replaced by stud frame Glass Reinforced Cement (GRC) cladding 10. The stud frame Glass Reinforced Cement (GRC) cladding 10 is hung from the floors 12 of the building (and/or other load-bearing elements of the building structure) by means of angle cleats 14 and bolts (not shown in Fig. 1A) or other suitable mechanisms.
Glass Reinforced Cement (GRC) comprises cement reinforced with alkali resistant glass fibre that can be used for many purposes including the production of a cladding material.
In stud frame GRC cladding 10, a GRC skin 16 is mechanically linked to a steel frame known as a stud frame 18. When attached to a GRC skin 16 the stud frame 18 acts to stiffen the GRC skin 16. The GRC skin 16 is attached to the stud frame 18 by means of gravity anchors 20 and flex anchors 22 (not differentiated in Fig. 1 A). Gravity anchors 20 support the weight of the GRC skin 16 on the stud frame 18 and flex anchors 22 restrain the GRC skin 1 .
In traditional methods of building construction, the load-bearing components of the building structure is designed to bear the load of its own weight and that of the cladding or brickwork/blockwork. The building structure is further designed to bear the load of persons and fittings residing within the building and traffic (vehicular and otherwise) within the building. Collectively, the load from all of these sources acting on the building structure is known as the vertical load. When stud frame GRC cladding 10 is hung from the building structure, the stud frame 18 is designed to enable the stud frame GRC cladding 10 to resist wind forces acting on it, which would otherwise distort the stud frame GRC cladding 10 by causing direct bending and racking or sideways sway.
In both of the above traditional methods of building construction, the interior facades of the walls of the building require finishing by the attachment of insulating material 24 and plasterboard 26. In the case of stud frame GRC cladding 10 insulating material 24 can be inserted into the stud frame 18 itself or attached as an additional layer adjacent to the stud frame 18 as shown in Fig. 1A.
Summary of the Invention
According to the invention there is provided a building panel comprising a substantially rectangular stud frame including a plurality of substantially parallel studs joined at each end by transverse top and bottom tracks, and a glass reinforced cement (GRC) skin attached to one side of the frame, the studs being sufficient in number and dimensions that the panel, when mounted in a vertical plane, is capable of serving as a vertical load-bearing component of a building.
The invention further provides a method of constructing a building using building panels each comprising a substantially rectangular stud frame including a plurality of substantially parallel studs joined at each end by transverse top and bottom tracks and a GRC skin attached to one side of the frame, the method comprising mounting a first building panel substantially vertically on a foundation to serve as a ground floor outer wall of the building, mounting a second building panel substantially vertically above and coplanar with the first panel to serve as a first floor outer wall of the building, mechanically attaching the bottom track of the second panel to the top track of the first panel, mounting a plurality of joist support members along the top track of the first panel, inserting the ends of substantially horizontal joists into respective joist support members, and forming a floor on the joists, the first panel supporting the combined weight of the second panel, the edge of the floor, and the weight of any further building components transmitted vertically down through the second panel, and the second panel supporting the weight of said any further building components.
The invention further provides a building in which the outer walls comprise building panels serving as vertical load-bearing components of the building, each panel comprising a substantially rectangular stud frame including a plurality of substantially parallel studs joined at each end by transverse top and bottom tracks and a GRC skin attached to one side of the frame.
The invention reverses the traditional building techniques described above in that GRC panels may now be used as the primary load-bearing components of the building, avoiding the need for a pre-built load-bearing skeleton to which the panels are merely attached as cladding. This substantially reduces the erection time ands cost of the building.
Brief Description of the Drawings
Embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings, in which:
Fig. 1 A is a transverse section of a traditionally constructed wall employing stud frame GRC cladding;
Fig. 2 is a rear elevation of a non-limitative example of a domestic house embodying the invention;
Fig. 3 is a front elevation of an embodiment of GRC panel according to the invention;
Fig. 4 is a horizontal section of the GE-C panel of Fig, 3, taken along the D-D axis of Fig. 3. looking in the direction of the arrows on the D-D axis;
Fig. 5 is a front elevation of the stud frame of the GRC panel of Fig. 3;
Fig. 6 is a vertical section of the GRC panel of Fig. 3, taken along the E-E axis of Fig. 3, looking in the direction of the arrows on the E-E axis;
Fig. 7 is a vertical section taken along the axis B-B in Fig. 2;
Fig. 8 is a vertical section taken along the axis C-C in Fig. 2; and
Fig. 9 is an exploded perspective view of a second embodiment of building panel according to the invention.
Description of the Preferred Embodiments
For the sake of brevity, a stud frame GRC building panel in accordance with the invention will be designated herein as a load-bearing GRC panel.
In the typical domestic two storey house shown in Fig. 2, each outer wall of the house comprises two vertical load-bearing GRC panels 28, one load-bearing GRC panel 28 forming the part of the outer wall that corresponds with the ground floor of the house and the other load-bearing GRC panel 28, which is mounted vertically upon and coplanar with the first panel, forming the part of the outer wall that corresponds with the first floor of the house. In order to distinguish between the two load-bearing GRC panels 28 which form the ground and first floor outer walls, the former will be referred to as the ground floor panel 29 and the latter as the first floor panel 30.
Fig. 3 is a front elevation of a typical load-bearing GRC panel 28. Such load-bearing GRC panels 28 can be of variable height or width as required for a particular application.
Fig. 4 is a horizontal section of the load-bearing GRC panel 28 of Fig. 3, taken along the D-D axis of Fig. 3, looking in the direction of the arrows on the D-D axis. The GRC panel 28 comprises a GRC skin 16 attached to one side of a stud frame 18. The stud frame 18 is a steel framework comprising a plurality of substantially parallel elongate components known as studs 34 joined at each end by transverse top and bottom tracks 40, 38 respectively (Fig. 5). The studs 34 are typically positioned to be approximately 600mm apart (unless the stud frame 18 is to be used for a wall that includes a window, in which case the studs 34 are positioned around the window as appropriate). The tracks are perpendicular to the studs 34. The inside surface of the skin 16 is recessed to form a cavity 32, the skin 16 being mechanically attached to the frame 18 by gravity anchors and flex anchors as previously described. A combined layer of insulation 24 and plasterboard 26 is attached to the other side of the stud frame, the layer 24/26 being mechanically fixed to the studs 34.
It is the stud frame 18 that confers the necessary vertical load-bearing capability on the GRC panel 28 to allow it to be used as a structural load-bearing component of the building, and also provides the necessary resistance to horizontal loads imposed by wind pressure. Fig. 5 shows the stud frame 18 for a load-bearing GRC panel 28 in more detail. The stud frame 18 comprises a plurality of studs 34 of equal length (e.g. Ayreshire Steel Framing component
CS 100/12) aligned in parallel and having a vertical orientation in use. There is attached at one end of all of the studs 34 a horizontal elongate component known as a bottom track 38 (e.g. Ayreshire Steel Framing component CR100/12). At the other end of all of the studs 34 there is attached a component comprising two elongate heavy-gauge steel members, aligned in parallel and contacting each other along their longer axes, or other suitably designed structural member. This horizontally oriented elongate component is known as a top track 40 (e.g. Ayreshire Steel Framing components CR100/12 and UR200/20). Approximately halfway between the bottom and top tracks a horizontal bracing member 42 (e.g. Ayreshire Steel Framing components CS 100/12) is attached to all of the studs 34. The stud frame 18 may also include diagonal bracing members, not shown.
For ease of description, the outer-most studs 34 in the stud frame 18 are defined as So and their neighbouring studs 34 as S\. The stud 34 neighbouring the left-most Si stud is defined as S2.
In the space between S0 and Si there are provided two gravity anchors 20, each of which is attached to a single stud 34. In the space between SI and S2 there are no gravity anchors 20 attached to the studs 34. In each of the remaining spaces between the studs 34 there is provided a single gravity anchor 20 wherein each gravity anchor 20 is attached to the left- most stud 34 of each of the pairs of studs 34 separated by these remaining spaces. In each case, the gravity anchors 20 are attached to the studs 34 in a position proximal to the bottom track 38.
In the space between S0 and Si four flex anchors 22 are attached to So and four flex anchors 22 are attached to Sj. On both S0 and Si, the flex anchors 22 are positioned to be equi- distantly distributed between the top track 40 and the gravity anchors 20. In practice flex anchors are positioned on a single stud to be separated by approximately 600 mm.
In the space between Si and S2 there are no flex anchors 22 attached to the studs 34. In each of the remaining spaces between the studs 34, there are attached four flex anchors 22 attached to the left-most stud 34 of the stud pair separated by each of these remaining spaces.
The stud frame 18 of the load-bearing GRC panel 28 has a number of features which enables it to confer wind and vertical load-bearing capability on the GRC panel. Of particular note in this regard is the use of the two-membered top track 40 (or other suitably designed structural member) in the stud frame 18 of the load-bearing GRC panel. However in the load-bearing GRC panel the stud frame 18 is required to carry the weight of roof of the building, and in the case of a multi-storey building, the weight of any storeys above the panel. Consequently the top of the stud frame 18 in the load-bearing GRC panel requires the strengthening provided by the two-membered top track 40 (or other suitably designed structural member). The stud frame 18 of the load-bearing GRC panel is also strengthened to support the vertical loads to which the panel is subjected in use through a suitable choice of design variables such as the cross-sectional thickness of the studs 34 and the spacing between adjacent studs 34 in the stud frame 18 (i.e., the number of studs 34). The bracing members do not significantly affect the load-bearing ability of the panel, but are primarily included to resist rhombic deformation.
Fig. 6 is a vertical section of the load-bearing GRC panel 28 of Fig. 3, taken along the E-E axis of Fig. 3, looking in the direction of the arrows on the E-E axis. Fig. 6 shows the two- membered top track 40 and the bracing 42 attached to a stud 34, wherein the stud 34 is attached to a layer of insulating material 24 and the insulating material 24 is attached to a layer of plasterboard 26. Between the stud 34 and the GRC skin 16 there is a cavity 32 and the stud 34 is attached to the GRC skin 16 by means of gravity and flex anchors (neither of which are shown in Fig. 6).
Fig. 7 is a vertical section of the base of the ground floor panel 29 of the house shown in Fig. 2, taken along the axis B-B in Fig. 2. The ground floor panel 29 is mechanically attached to the structural ground beam (foundation) 46 of the house by means of Ml 2 Hilti HSA
expanding bolts 48 (other mechanical attachment means could also be used to suit the specific design requirements of the building in question).
Fig. 8 is a vertical section of the join between the ground floor panel 29 and first floor panel 30 of the outer wall of the house shown in Fig. 2, taken along the axis C-C in Fig. 2. The top track 40 of the stud frame 18 of the ground floor panel 29 is mechanically fixed to the bottom track 38 of the stud frame 18 of the first floor panel 30 by through-bolts 49.
A strengthening rib 50 extends around the periphery of the GRC skin 16 to provide further rigidity to the GRC skin 16. The joint 52 between the strengthening rib 50 of the ground floor panel 29 and that of the first floor panel 30 is sealed with MASTIC or other water-tight means.
A number of steel support members (joist hangers) 54 are mounted at intervals along the top track 40 of the stud frame 18 of the ground floor panel 29. One end of a respective floor joist 56 of the first storey of the house is inserted in each joist hanger 54. The other end of each floor joist (not shown) is inserted within a respective similar joist hanger mounted on the opposite wall of the house which is constructed from panels similar to the panels 29, 30. Other joist support means could also be used to suit the specific design requirements of the building in question. Floorboards are fixed to the joists in conventional manner to form a floor supported by the joists 56.
Having described (with reference to Fig. 8) how a wall is formed through the mechanical attachment of two load-bearing GRC panels, it is useful at this point to compare Figs. 8 and 1 A in relation to the manner by which a floor is brought into engagement with a wall.
Fig. 1 A shows a transverse section of a traditionally constructed wall employing stud frame GRC cladding. In Fig. 1 A it can be seen that the stud frame GRC cladding 10 hangs from the floors 12 by means of angle cleats 14 and bolts (not shown in Fig. 1 A). This can be contrasted with Fig. 8 in which the load-bearing GRC panels 28 replace the traditional
structure of the house and the floors joists 56 are hung from the load-bearing GRC panels 28 by joist hangers 54.
Returning to the description of the construction of atypical domestic house by means of load- bearing GRC panels 28, for the sake of brevity in the following description, the corners of a wall of the house which are closest to the roof of the house will be henceforth known as the top corners of the wall.
Returning to Fig. 2 which is a rear elevation of a typical domestic house, it can be seen that each of the adjoining walls of the house, e.g. the back wall 56 and adjacent side-wall 58, are mechanically attached by means of brackets 60 wherein at least one bracket 60 is provided at each junction between the top corners of each adjoining wall. Such brackets 60 are not normally used when GRC panels are being used for cladding purposes. The brackets are specifically designed to meet the load requirements of a given building through the optimisation of design parameters such as the dimensions of the bracket and the thickness of the steel from which the bracket is made. When all the walls of the house are connected by such brackets 60 the resultant is a self-supporting structure. To complete the house, the roof 62 is mechanically attached to the load-bearing GRC panels 28 in a similar manner to that used for the attachment of a roof 62 to the structure of a traditionally constructed house.
As mentioned, the number and dimensions of the studs 34, which are the primary vertical load-bearing components of the panels 28, are selected such that the ground floor panel 29 supports the combined weight of the first floor panel 30, the edge of the floor comprising the joists 56 and attached floorboards, and the weight of any further building components, such as the roof, transmitted vertically down through the first floor panel 30, while the first floor panel 30 supports the weight of the further building components such as the roof.
Fig. 9 is a perspective exploded view of a second embodiment of load-bearing GRC building panel. In Fig. 9, the same reference numerals have been used for parts which are the same as or equivalent to corresponding parts of the panel 28. It will be understood that the panel
shown in Fig. 9 is a particularly simple panel intended to demonstrate the principles of construction, and is not representative of an actual panel which would be used in constructing a building. For example, the demonstration panel has a small area whereas the corresponding actual panel will have a much larger area. Also, only the outer studs 34 (corresponding to So in Fig. 5) are shown, those in between (such as Si, S ) being omitted but present in practice. In addition, only one gravity anchor 20 and one flex anchor 22 is shown, although there will in the actual panel be many such anchors as indicated in Fig. 5.
In the Fig. 9 panel, the top and bottom tracks 40, 38 respectively are generally U-shaped channels (the top channel being inverted) which embrace the corresponding ends of the studs 34. The layer of insulation material 24 with attached plasterboard 26 is mounted on the stud frame 18 by bolts whose heads are embedded in the material 24 and whose shafts 70 pass through corresponding holes in the frame 18 to be secured by nuts. The inner ends of the gravity and flex anchors 20, 22 are bolted to the studs 34 and their outer ends are embedded in the GRC skin 16. The GRC panel shown in Fig. 9 can be used in the construction of buildings in the same way as described for the panel 28. The dashed lines show how the combined insulation/plasterboard panel 24/26 can be cut away to make room for a joist hanger 54. Although this is shown at one corner of the combined panel, it can be cut away at any point along the top of the panel where it is desired to accommodate a joist hanger.
The invention is not limited to the embodiments described herein which may be modified or varied without departing from the scope of the invention.