GB2564555A

GB2564555A - Connection and alignment of building elements

Info

Publication number: GB2564555A
Application number: GB1809136.3A
Authority: GB
Inventors: Alexander Allen William
Original assignee: Insula Ltd
Current assignee: Insula Ltd
Priority date: 2017-06-03
Filing date: 2018-06-04
Publication date: 2019-01-16
Also published as: GB2563085A; GB201809136D0; EP3409854A1; GB201708885D0

Abstract

A linkage assembly enables an interior building element, such as a concrete slab or wooden joist, to be connected to and aligned with an exterior building element, such as a balcony. The assembly comprises a flat metal plate 100 having a plurality of holes 120, 150, 170 and jigsaw profiled ends 110. In one arrangement, some of the holes receive reinforcing bars to enable the plate 100 to be cast into an edge face of a concrete slab. In another arrangement, some of the holes receive bolts to secure the plate 100 to a pre-cast slab. In yet another arrangement, some of the holes are used to secure the plate 100 to T-plates which are sandwiched between and secured to wooden joists. Other holes on the plate 100 receive and align connectors, such as brackets and thermal breaks, for connection to an exterior building element.

Description

CONNECTION AND ALIGNMENT OF BUILDING ELEMENTS

The present invention relates to connectors for attaching building elements, particularly balconies and similar external elements, to a building.

Attaching an external building element to a building can be achieved by making an aperture in the building envelope and fixing the element to an internal floor surface, such as a concrete slab or timber joist. Balconies are a popular external element and are becoming progressively larger with floor to ceiling windows and glass doors. This creates many problems such as how to create a load bearing connection between the balcony and the internal floor; how to ensure the balcony is aligned accurately; how to securely fix a door/window unit into the aperture; how to distribute the loads generated by the door/window unit back to the load bearing internal floor; how to smoothly link the internal floor surface to the external floor surface; and how to comply with building regulations such as thermal bridging and disability access.

Previous attempts at solving some of these problems have been made. One approach is to cast reinforcing bars (rebar) into the internal floor concrete slab which protrude out of one end of the slab. The ends of the protruding rebar are provided with bolt connectors. A metal linking bracket, which extends the depth of the building envelope, is bolted onto the rebar and the external element is bolted onto the bracket. Disadvantageously, this creates a thermal bridge through the building envelope. Also, since the rebar is unlikely to be accurately aligned within the concrete slab, alignment of the bracket and of the external element can be difficult and time-consuming. The exposed, protruding rebar also creates thermal bridges, interferes with construction processes and typically cannot be achieved with slip form construction processes. UK patent application GB2462830 describes a connection system for providing a thermal break between external structures such as balconies, and the building's internal structure to which they are connected. The connection comprises internal and external metal plates bolted to opposite flanges of an I beam section formed from a thermally insulating material. The connection is located within an insulating cavity of a wall.

In a first aspect, the present invention provides a linkage for enabling connection of an interior building element and an exterior building element, the linkage comprising a linkage plate securable to one of the interior building element and the exterior building element, the linkage plate having a plurality of connector holes for receiving a plurality of connectors, the connector holes arranged to align the received connectors with each other for connection to the other of the interior building element and the exterior building element.

Advantageously, the linkage embodying the present invention can be accurately aligned with a building element. Subsequently, the linkage plate is able to receive and align a plurality of connectors to ensure that an exterior building and an interior building element can be easily and securely connected in proper alignment with each other.

Preferably, each end of the linkage plate has a jigsaw profile to enable a plurality of linkage plates to be connected and aligned with each other. In this way, if a single linkage plate is not long enough to fill the desired span, several linkage plates can be joined together while still ensuring proper alignment of any attached connectors.

In one preferred arrangement, the linkage further comprises a plurality of anchors secured to the linkage plate and extending away from a rear face of the linkage plate enabling the linkage to be fixedly cast into a face of a concrete building element with the plurality of anchors located inside the concrete building element. Casting a linkage into a concrete slab is an effective way of securing the linkage to a building element. When connectors are subsequently fixed to the connector holes on the front face of the linkage plate and connected to another building element, the load is transferred into the concrete slab via the anchors.

Preferably, the front face of the linkage plate is substantially flat, and the anchors do not protrude significantly past the front face of the linkage plate. By having no protruding elements on the front face, construction using the linkage is simplified and slip form construction processes can be used.

Preferably, a face of the linkage plate that is to be cast into a face of a concrete building element further includes a plurality of covers placed over at least some of the connector holes to prevent ingress of concrete slurry into the covered connector holes. The covers prevent the connector holes from being filled with concrete so that connectors can still be inserted into the holes once the concrete is set. The covers are formed from a pliable material which gives way when the connectors are inserted into the holes.

Preferably, at least some of the anchors are each secured to the linkage plate via a female coupling located in a connector hole, the female coupling having a fastener hole for receiving a fastener to secure a connector to the linkage plate and to the associated anchor. In this way, connectors are attached via the linkage plate to anchors located inside a concrete slab and can therefore safely support a large amount of weight.

In a second preferred arrangement, the linkage further comprises a plurality of strap plates arranged at right angles to the linkage plate, each strap plate comprising a plurality of fastener holes for receiving fasteners to secure the strap plate to a first surface of a building element, the linkage plate comprising a plurality of fastener holes for receiving fasteners to secure the linkage plate to a second surface of the building element, perpendicular to the first surface. In this way, the linkage can be securely fastened to a building element such as a pre-cast concrete slab.

Preferably, the linkage plate comprises a plurality of sets of strap plate holes and each strap plate comprises a set of corresponding lugs and wherein the lugs are received by the strap plate holes and welded to secure the strap plates to the linkage plate. This arrangement of holes and lugs ensures that the safety critical junction between the strap plate and the linkage plate can support heavy weights, particularly when the strap plates are aligned with a horizontal surface of a building element and the linkage plate is aligned with a vertical surface of the building element.

Preferably, the fastener holes in each strap plate are arranged to enable fasteners to be inserted so that no two fasteners are in line with each other in a direction perpendicular to the second surface of the building element. This arrangement prevents fracture lines developing in the building element that the strap plate is fastened to.

Preferably, where the building element is a reinforced concrete slab, adjacent fastener holes in each strap plate are spaced apart in a direction parallel with the second surface by a distance equal to half the distance between reinforcing bars in the reinforced concrete slab. In this way, if a fastener inserted through the strap plate encounters a reinforcing bar, the fastener can instead be inserted through an adjacent hole and will be located between adjacent reinforcing bars .

Preferably, each strap plate has a profile that is narrower near the junction between the strap plate and the linkage plate then widens in a direction parallel with the second surface. This creates a ledge parallel with an end face of the building element. When concrete or other floor-finishing material is poured over the building element and the strap plate, the ledge increases the force resisting the linkage from being pulled out of position. For example, each strap plate may have a profile in the shape of a T, the stem of the T being attached to the linkage plate.

In a third preferred arrangement, the linkage further comprises a plurality of T-plates, each T-plate comprising a cross-piece plate and a stem plate fixed together at right angles to each other, the cross-piece plate being secured flat against the linkage plate and the stem plate extending at a right angle away from the linkage plate, the stem plate having a plurality of fastener holes for receiving fasteners to secure the stem to a building element. This arrangement is more suitable for attachment to wooden joists. In particular, where the building element comprises a plurality of pairs of wooden joists, each stem plate is clamped or sandwiched between a pair of wooden joists in use to secure the stem to the building element.

Preferably, each fastener hole in a stem plate is surrounded by a raised, sharpened edge. This sharpened edge digs into the joists either side of the stem plate to better secure the stem plate to the joists.

Preferably, each fastener hole in a stem plate has a diameter larger than the fastener. In this way, the fasteners do not come into contact with the stem plate or the timber joists and do not bear any load which might shear the fastener. Conversely, the fasteners also do not apply any force to the joists which might split the timber along the grain. Loads are instead supported by the raised, sharpened edges which distribute forces in multiple directions on the surface of the joists.

Preferably, each fastener received by a fastener hole in a stem plate comprises a bolt and, in use, a clamping force is applied to sandwich each stem plate between a pair of wooden joists by washers located between each joist and nuts screwed onto the ends of each bolt. This arrangement is an effective way of ensuring a high clamping force to sandwich the stem plate between pairs of joists.

Preferably, the fastener holes in the stem plate are arranged to distribute the clamping force evenly. This arrangement increases the strength of the connection between the stem plate and the joists.

Preferably, each cross-piece plate comprises a plurality of fastener holes which are aligned with connector holes, the aligned holes for receiving fasteners to secured the crosspiece plate to one face of the linkage plate and a connector to the opposite face of the linkage plate. In this way, connectors are attached via the T-plates to the joists and can therefore safely support a large amount of weight.

Preferably, at least one connector received by the linkage plate comprises a thermal break. This ensures that no thermal bridge is formed between the interior and exterior building elements .

Preferably, at least one connector received by the linkage plate comprises a bracket to support a floor surface placed above the bracket. In this way, weight from above the linkage can be supported by the linkage and transferred to the interior building element.

Preferably, at least one connector received by the linkage plate comprises an extension bracket to extend the connector to span the depth of a building envelope. Advantageously, an extension brackets of any desired size can be used to span the required depth.

Preferably, the extension bracket comprises a first plate having a first plurality of fastener holes for receiving fasteners to connect the extension bracket to the linkage plate, the first plurality of fastener holes being slotted in a first direction, and a second plate having a second plurality of fastener holes for receiving fasteners to connect the extension bracket to a building element, the second plurality of fastener holes being slotted in a second direction perpendicular to the first direction. In this way, the extension bracket enables adjustment of the exterior element relative to the interior building element in two perpendicular directions to ensure perfect alignment. Optionally, a thermal break is connected between the extension bracket and the linkage plate. This avoids the creation of a thermal bridge.

In a second aspect, the present invention provides an extension bracket for connecting an interior building element to an exterior building element and spanning the depth a building envelope, the extension bracket comprising: a first plate having a first plurality of fastener holes for receiving fasteners to connect the extension bracket to the interior building element, the first plurality of fastener holes being slotted in a first direction; and a second plate having a second plurality of fastener holes for receiving fasteners to connect the extension bracket to the exterior building element, the second plurality of fastener holes being slotted in a second direction perpendicular to the first direction. Such extension brackets simplify the connection and alignment of exterior building elements to interior building elements whatever the depth of the building envelope.

Preferably a thermal break is connected to one of the first plate and the second plate. This avoids the creation of a thermal bridge.

Preferably, the extension bracket is raked between the first plate and the second plate such that the exterior building element is connected at a different height than the interior building element. Advantageously, this permits a floor height of an exterior building element to be adjusted to match an interior floor height.

Preferably, the extension bracket comprises a water-resistant bead. Preferably the extension bracket has an upper face for supporting a floor surface placed above the extension bracket. Preferably, the extension bracket has a slidable plate extending in the second direction between a pair of the second plurality of fastener holes, the slidable plate for supporting fasteners received by the pair of fastener holes to constrain the fasteners move in tandem within the slots in the pair of fastener holes. Each of these preferred features improves the usefulness and usability of the extension bracket.

Preferred embodiments of the invention will now be described with reference to the accompanying drawings in which:

Figure 1 is a plan view of a cast-in plate;

Figure 2 illustrates a cast-in plate assembled with anchors;

Figure 3 is a top view of the assembly of Figure 2;

Figure 4 illustrates a cast-in plate assembly including components for connecting to an external element;

Figure 5 is a side perspective view of the assembly of Figure 4;

Figure 6 is a side view of a cast-in plate assembly including a decking;

Figure 7 is a bottom view of the assembly of Figure 6;

Figure 8 illustrates a bolt-on assembly;

Figure 9 illustrates a strap plate component of the bolt-on assembly of Figure 9;

Figure 10 illustrates a bolt-on assembly including components for connecting to an external element;

Figure 11 illustrates the bolt-on assembly of Figure 10 connected to a concrete slab and showing a decking and interior floor surface;

Figure 12 illustrates a T-plate assembly and components for connecting to an external element;

Figure 13 illustrates a portion of the T-plate assembly of Figure 12 connected to two timber joists; and

Figures 14 and 15 illustrate an extension bracket.

Embodiments of the present invention enable an exterior building element, such as a balcony, canopy, walkway or similar structure, to be connected to and supported by an interior building element, such as a concrete floor slab or timber joist.

When fixing an external element to a building, the outer envelope (e.g. a brick, stone or timber wall) of the building is pierced and bridged. This envelope is typically at least 200mm thick, but may be over 300mm thick in buildings meeting Passive House standards. Successfully bridging this distance requires accurate alignment of the connection assembly.

The connection must also be strong enough to support the weight of the external element, balcony occupants and any door and/or window units. Floor to ceiling glazed units opening onto balconies may weigh between 500kg and 1500kg. Building envelopes are typically not load-bearing and bringing the window line into the building so that it is supported by the interior floor could compromise the insulation.

Figures 1 to 7 illustrate a linkage comprising a substantially planar and flat cast-in plate 100 and associated components for connecting the cast-in plate 100 between a concrete slab in the interior of a building and an external element such as a balcony. In use, the cast-in plate 100 is cast into the end of a concrete slab so that a front face 105 of the cast-in plate 100 is exposed for connection to an external building element via one or more associated components, but without the cast-in plate 100 protruding significantly away from the end of the concrete slab.

Casting the cast-in plate 100 into an internal concrete slab, such as a floor slab, is preferred, but it will be recognised that the plate could also be cast into a concrete slab forming an external building element. The process for attaching the external element to an internal element of the building nevertheless remains similar to the process described below and is within the capabilities of a suitably skilled person.

The cast-in plate 100 is made from a pressed or cut steel plate galvanised with zinc, or from any other suitable metal or any suitably strong and corrosion-resistant material. It is preferably 150mm to 350mm high and lm to 3.5m in width to match the size of a typical concrete floor slab, though different heights and widths may be used as required. Each end of the cast-in plate 100 has a matching jig-saw profile 110 to enable several cast-in plates 100 to be connected and accurately aligned when used with longer concrete slabs. The cast-in plate 100 is preferably 3mm to 15mm in thickness to be sufficiently strong to support attached connecting elements.

The cast-in plate 100 is provided with a plurality of holes and/or slots which pass through the cast-in plate 100. These are for use in securing the cast-in plate 100 to a concrete slab and for connecting the cast-in plate 100 to an external building element via suitable components. One preferred arrangement of holes and slots is illustrated in the Figures but it will be recognised that different arrangements will be suitable based on different requirements.

One or more sets, preferably pairs, of vertically aligned slots 120 are spaced apart along the width of the cast-in plate 100. In use, each set of slots 120 receives a connector or support component, such as the angled brackets 130 illustrated in Figure 4, on the front face 105 of the cast-in plate 100.

Prior to casting the cast-in plate 100 into a concrete slab, covers made from foam rubber or other suitably pliable material are adhered to the rear face 140 of the cast-in plate 100, over each slot 120. These covers prevent the ingress of concrete into each slot 120 but do not prevent the subsequent attachment of a bracket 130 or other suitable connector.

One or more countersunk or counterbored circular anchor holes 150 are spaced apart along the width of the cast-in plate 100, preferably adjacent to a top edge 155 of the cast-in plate 100. Each anchor hole 150 permits an anchor, such as the wavy tail steel anchors 160 illustrated in Figure 2, to be screwed or bolted onto the rear face 140 of the cast-in plate 100 before the cast-in plate 100 is cast into a concrete slab. The anchors 160 can be any anchor suitable for supporting structural loads.

One or more sets of countersunk or counterbored anchor holes 170 are spaced apart along the width of the cast-in plate 100. Preferably there are two sets of four anchor holes 170, one set adjacent each end of the cast-in plate 100. Each anchor hole 170 receives an anchor such as a length of steel reinforcing bar 180 before the cast-in plate 100 is cast into a concrete slab. Each reinforcing bar 180 is attached to the rear face 140 of the cast-in plate 100 via a female coupler 190. The female coupler 190 permits a connector, such as the thermally broken coupling 200 illustrated in figure 4, to be screwed or bolted to the front face 105 of the cast-in plate 100 through the same set of anchor holes 170.

To cast a concrete slab, a formwork structure is made for receiving a concrete pour. An appropriate rebar structure is arranged in the formwork and tied together with wire at any crossing points. An assembly comprising the cast-in plate 100 together with anchors such as wavy tail anchors 160 and lengths of rebar 180 is placed in the formwork. The front face 105 of the cast-in plate 100 is abutted against a base board at one edge of the formwork. The top edge 155 of the cast-in plate 100 is aligned with what will be the top of the concrete slab. This is most easily achieved by placing the cast-in plate 100 upside-down in the formwork so that the top edge 155 abuts the bottom of the formwork structure. The rebar 180 of the assembly is tied to the rebar structure at any crossing points to secure it in place. Concrete is poured into the formwork. When the concrete is set, the formwork can be removed leaving the cast-in plate 100 embedded in the edge of the resulting slab and secured by the anchors 160 and rebar 180 inside the slab. Casting the cast-in plate 100 into the concrete slab in this way ensures an accurate alignment of the cast-in plate 100 in all three planes of motion and without risk of twisting and greatly simplifies subsequent attachment of an external element.

When the concrete slab is in place in the building, brackets 130, couplings 200 and/or other suitable connector components are attached to the cast—in plate 100. Connector components enable an exterior element to be connected to, aligned with and supported by the concrete slab. Preferred connector components are illustrated in the Figures, but it will be recognised that different arrangements will be suitable based on different requirements and many suitable connectors are known in the art.

Brackets 130 have lugs matching the slots 120 on the cast-in plate 100. The lugs are pushed into the slots 120, pushing aside the foam rubber adhered to the rear face 140 of the cast-in plate 100, then pushed down to securely lock them in position.

The brackets 130 are sized and shaped such that, when in position, the top edges of each bracket 130 are aligned with each other and with the top edge 155 of the cast-in plate 100 and, consequently, with the top edge of the concrete slab.

When in place, each bracket 130 supports loads from above and transfers these loads into the concrete slab via the cast-in plate 100.

Each coupling 200 preferably comprises a thermal break 210 such as the one described in UK patent application GB2462830. The thermal break 210 is offered up to the cast-in plate 100 and bolted through the holes 170 into the female couplers 190 to secure the thermal break 210 to the rebar anchors 180. The thermal break 210 transfers the weight of any attached external element into the concrete slab and also acts as a thermal barrier between the interior and exterior of the building, preventing the creation of a thermal bridge. An extension bracket 220 is bolted to the thermal break 210 and extends the coupling 200. The size of the extension bracket 220 is selected so that the coupling 200 spans the full depth of the building envelope. An external element is bolted to the extension bracket 220.

The couplings 200 are sized and shaped such that, when in position, a top edge of each coupling 200 is aligned with the top edge 155 of the cast-in plate 100 and, consequently, with the top edge of the concrete slab. As well as supporting the weight of an external element, each coupling 200 therefore also support loads from above and transfers these loads into the concrete slab. Since each coupling 200 is connected to rebar anchors 180 extending into the concrete slab, they are able to support large loads, such as the weight of door and window units.

As illustrated in Figures 6 and 7, a floor decking 230 is placed on top of the brackets 130 and couplings 200. The decking 230 also extends over the concrete slab. A groove on the bottom of the decking 230 is provided to aid adhesion between the decking and the building envelope (e.g. brickwork) using a suitable adhesive such as soft mastic.

The decking 230 creates a bridge between the interior of the building and the exterior element and helps ensure a smooth transition between the two. The decking 230 is sized to extend the full width of an opening made in the building envelope, e.g. a door/window unit providing access to a balcony or other exterior element. Matching locking profiles at each side of the decking 230 enable several pieces of decking to be connected so that the decking extends the full depth of the building envelope.

The decking 230 is made from a non-thermally conductive material, preferably a rigid composite material, to prevent the creation of a thermal bridge. Grooves in the top surface of the decking 230, running parallel with the cast-in plate 100, provide grip and enable water to run off each end of the decking 230 without pooling on the surface.

When the decking 230 is in place, it can be used as a baseline for creating an interior floor surface on top of the concrete slab. For example, a layer of cement can be poured over the concrete slab and levelled to match the top surface of the decking 230.

Figures 8 to 11 illustrate a linkage comprising a bolt-on assembly 500 and associated components for connecting the bolt-on assembly 500 between a concrete slab in the interior of a building and an external element such as a balcony. The bolt-on assembly 500 comprises one or more, preferably two, substantially flat and planar strap plates 510 and a substantially flat and planar connector plate 520 at right angles to the strap plates 510.

In use, each strap plate 510 is bolted to an upper, substantially horizontal surface of a previously cast concrete slab 530. The connector plate 520 is bolted to a side, substantially vertical edge of the concrete slab 530. A front face 540 of the connector plate 520 is available to receive one or more connection components for connection to an external building element.

Bolting the bolt-on assembly 500 to an internal concrete slab, such as a floor slab, is preferred, but it will be recognised that the assembly 500 could also be bolted onto a concrete slab forming an external building element. The process for attaching the external element to an internal element of the building nevertheless remains similar to the process described below and is within the capabilities of a suitably skilled person.

The strap plates 510 and connector plate 520 are each made from a pressed or cut 3mm-15mm thick steel plate galvanised with zinc, or made from any other suitably strong and corrosion-resistant material. The strap plate 510 is approximately 300mm to 400mm in length and width. The connector plate 530 is preferably 150mm to 350mm high and lm to 3.5m in width to match the size of a typical concrete floor slab, though different heights and widths may be used as required. Each end of the connector plate 530 has a matching jig-saw profile 550 to enable several connector plates 530 to be connected and accurately aligned when used with longer concrete slabs.

The strap plates 510 and connector plate 520 are welded together, preferably MIG welded, to form the bolt-on assembly 500. This weld is placed under high loads and is safety critical. To ensure that the bolt-on assembly 500 is able to support such loads, the strap plate 510 is provided with a plurality of lugs 560, preferably three or more. The lugs 560 are received by and protrude through corresponding holes 570 in the connector plate 520. The junction is welded on both sides to secure the strap plate 510 to the connector plate 520 .

The connector plate 520 is provided with a plurality of holes and/or slots which pass through the connector plate 520. These are for use in securing the connector plate 520 to a concrete slab and for connecting the connector plate 520 to an external building element via suitable components. Figure 8 show a minimal arrangement of holes but it will be recognised that different arrangements will be suitable based on different requirements .

Although not shown in Figure 8, the connector plate 520 may be provided with one or more sets of vertically aligned slots similar to the slots 120 shown in Figure 1. In use, each pair of slots receives a support component, such as the angled brackets 580 illustrated in Figure 10, on the front face 540 of the connector plate 520.

One or more slab bolt holes 590 are provided on the connector plate 520. Preferably there are two sets of four bolts holes 590, one set adjacent each end of the connector plate 520. In use, the connector plate 520 is bolted to the concrete slab 530 through the bolt holes 590. Optionally an adhesive or chemical anchor is used to help secure the bolts in place.

One or more connector holes 600 are provided on the connector plate 520. Preferably there are two sets of four connector holes 600, one set adjacent each end of the connector plate 520, located within each set of four slab bolt holes 590. In use, a connector, such as the thermally broken coupling 610 illustrated in figure 10, is screwed or bolted to the front face 540 of the connector plate 520 through the connector holes 600. Preferably, the connector holes 600 are countersunk or counterbored on a rear surface of the connector plate 520 so that the coupling 610 can be screwed or bolted to the connector plate 520 from the rear side without leaving any protrusion which would prevent the connector plate 520 from lying flat against the side of the concrete slab 530.

The strap plate 510 is provided with a plurality of bolt holes 620. In use, the strap plate 510 is bolted to the concrete slab 530 through some of the bolt holes 620. Optionally an adhesive or chemical anchor is used to help secure the bolts 630 in place.

The bolt holes 620 are arranged in at least three rows which run parallel to the side edge of the concrete slab 530 when the strap plate 510 is bolted into position. Each row is spaced apart by 100mm. Each row comprises one or more bolt holes 620 spaced apart by integer multiples of 50mm. In a preferred arrangement, the first row has a single bolt hole 620 located centrally along the width of the strap plate 510. The second and third rows each have an identical set of four holes located at 50mm and 100mm on each side of the centre point.

This arrangement of bolt holes 620, and other similar arrangements, enable the strap plate 510 to be bolted to a concrete slab 530 with five bolts 630 arranged in a V-shape. Between rows of bolts 630, no two bolts are in line with each other. This avoids strings of parallel holes being drilled into the concrete slab 530 to receive the bolts 630 and reducing the likelihood of fracture lines developing in the concrete slab 530.

Typically, the concrete slab 530 will have rebar cast inside it and each length of rebar will be 100mm apart. If, through poor luck, rebar is encountered when drilling into the concrete slab, a hole can instead be drilled 50mm to the side knowing that there will not be rebar at that position. An alternative set of bolt holes 620 in the strap plate 510 can then be used to bolt the strap plate 510 to the concrete slab 530. As a consequence, some of the bolts 630 will be in line with each other, but having sufficient bolts to create a strong connection is a more important consideration.

When the concrete slab 530 is in place in the building, brackets 580, couplings 610 and/or other suitable connectors are attached to the connector plate 520. Connectors enable an exterior element to be connected to, aligned with and supported by the concrete slab 530. Preferred connectors are illustrated in the Figures but it will be recognised that different arrangements will be suitable based on different requirements and many suitable components are known in the art.

Brackets 580 have lugs matching slots on the connector plate 520. The lugs are pushed into the slots and the bracket 580 is then pushed down to securely lock it in position. The brackets 580 are sized and shaped such that, when in position, the top edges of each bracket 130 are aligned with each other and are above the upper surface of the concrete slab 530. In particular, the top edge is higher than the bolts 630 used to connect the strap plate 510 to the concrete slab 530. When in place, each bracket 580 supports loads from above and transfers these loads into the concrete slab 530 via the bolt-on assembly 500.

Each coupling 610 preferably comprises a thermal break 640 such as the one described in UK patent application GB2462830. The thermal break 640 is bolted or screwed to the connector plate 520 through the connector holes 600, preferably from the rear before the bolt-on assembly 500 is bolted onto the concrete slab 530. The thermal break 640 transfers the weight of any attached external element into the concrete slab and also acts as a thermal barrier between the interior and exterior of the building, preventing the creation of a thermal bridge. An extension bracket 650 is bolted to the thermal break 640 and extends the coupling 610. The size of the extension bracket 650 is selected so that the coupling 610 spans the full depth of the building envelope. An external element is bolted to the extension bracket 650.

The couplings 610 are sized and shaped such that, when in position, a top edge of each coupling 610 is aligned with the top edges of the brackets 580. The extension bracket 650 is raked upwards to raise the top edge above the top surface of the concrete slab 530 and the bolts 630 through the strap plate 510. As well as supporting the weight of an external element, each coupling 610 therefore also support loads from above and transfers these loads into the concrete slab 530.

As illustrated in Figure 11, a floor decking 660 is placed on top of the brackets 580 and couplings 610. The decking 660 also extends over the concrete slab 530 and is raised above it and over the bolts 630 through the strap plate 510. A groove on the bottom of the decking 230 is provided to aid adhesion between the decking and the building envelope (e.g. brickwork) using a suitable adhesive such as soft mastic.

The decking 660 creates a bridge between the interior of the building and the exterior element and helps ensure a smooth transition between the two. The decking 660 is sized to extend the full width of an opening made in the building envelope. Matching locking profiles at each side of the decking 660 enable several pieces of decking to be connected so that the decking extends the full depth of the building envelope.

The decking 660 is made from a non-thermally conductive material, preferably a rigid composite material, to prevent the creation of a thermal bridge. Grooves in the top surface of the decking 660, running parallel with the connector plate 520, provide grip and enable water to run off each end of the decking 660 without pooling on the surface.

When the decking 660 is in place, it can be used as a baseline for creating an interior floor surface or screed 670 on top of the concrete slab 530. For example, a layer of cement can be poured over the concrete slab, covering the strap plate 510 and bolts 630, and levelled to match the top surface of the decking.

The strap plate 510 is preferably shaped to be wider at the end furthest from the edge of the concrete slab 530. Most preferably, the profile of the strap plate 510 is T-shaped, with the stem of the T connected to the connector plate 520. When cement or other screed is poured over the concrete slab 530, a ledge of screed is formed in front of the crossbar of the T. This ledge opposes movement of the strap plate 510 towards the edge of the concrete slab and helps reduce shear loads on the bolts 630.

Figures 12 and 13 illustrate a linkage comprising a T-plate assembly 1000 and associated components for connecting the T-plate assembly 1000 between timber joists 1010 in the interior of a building and an external element such as a balcony. The T-plate assembly 1000 comprises one or more, preferably two, T-plates 1020 and a substantially flat and planar connector plate 1030.

Each T-plate 1020 is similar in shape to a capital letter T having a substantially planar stem plate 1040 and a substantially flat and planar crossbar plate 1050 at right angles to each other, the T-plate 1020 being symmetrical about a plane through the stem 1040. A plurality of countersunk or counterbored holes 1055 are provided on the crossbar 1050. When the T-plate assembly 1000 is assembled, the crossbar of each T-plate 1020 is screwed or bolted to a rear surface of the connector plate 1030 through the holes 1055. Optionally an adhesive or chemical anchor is used to help secure the screws/bolts in place. The stem 1040 extending at right angles away from the connector plate 1030.

The stem 1040 of the T-plate is provided with a plurality of bolt holes 1060 having a diameter of approximately 40mm to 50mm. In use, each T-plate 1020 is sandwiched or clamped between two internal timber joists 1010 of a building and bolted to the joists 1010 through the bolt holes 1060. The connector plate 1030 is aligned parallel with end faces of the joists, with no deflection, and is available to receive one or more connection components for connection to an external building element.

Bolting the T-plate assembly 1000 to internal joists is preferred, but it will be recognised that the assembly 1000 could also be bolted onto joists forming an external building element. The process for attaching the external element to an internal element of the building nevertheless remains similar to the process described below and is within the capabilities of a suitably skilled person.

The T-plates 1010 and connector plate 1020 are each made from pressed or cut 3mm-15mm thick steel plates galvanised with zinc, or made from any other suitably strong and corrosion-resistant material. The plates forming the stem 1040 and crossbar 1050 of the T-plate 1010 are securely welded together. The connector plate 1020 is preferably 150mm to 300mm high, to match the size of typical timber joists, and and lm to 3.5m in width to match the size of a balcony, though different heights and widths may be used as required. Each end of the connector plate 1020 has a matching jig-saw profile 1070 to enable several connector plates 1020 to be connected and accurately aligned when used with longer external elements .

The stem 1040 is approximately lm to 1.5m in length and approximately the same height as the connector plate 1020. The crossbar 1050 is also approximately the same height as the connector plate 1020 and is at least approximately 80mm wide, and preferably approximately 250mm wide to provide a sufficient large area for the crossbar 1050 to be securely connected to the connector plate 1020.

Each bolt hole 1060 on the stem 1040 is provided with a steel ring which protrudes approximately 6mm either side of the surface of the stem 1040. Both sides of each ring are bevelled, preferably by grinding, to an angle of 45° to provide sharp edges. When the stem 1040 is sandwiched between timber joists 1010, these sharp edges dig into the timber and transfer loads placed on the T-plate assembly 1000 to the joists 1010.

The diameter of the bolts 1080 is much less than the dimeter of the bolt holes 1060 and less than holes drilled through the joists 1010 to receive the bolts 1080. This ensures that the bolts 1080 are not in contact with the joists 1010 and do not support or transfer any loads in order to remove the risk of the bolts 1080 breaking under shear forces or of the timber splitting along the grain under contact pressure from the fasteners .

Instead, loads are supported by the steel rings which provide efficient distribution of loads in multiple directions into the surface of the timber joists.

Large, flat washers 1090, preferably hexagonal plate washers, located between the bolts 1080 and the joists 1010 ensure that a strong and evenly distributed clamping force is applied to the joists 1010 as the nuts 1100 are tightened. This ensures that the rings around the bolt holes 1060 dig deeply into the timber joists 1010 to create a secure fixing. Preferably the nuts 1100 are nylon-insert lock nuts.

The bolt holes 1060 are distributed over the full area of the stem 1040 of the T-plate 1020 to ensure an even distribution of clamping forces and to resist turning motion of the T-plate assembly 1000 relative to the joists 1010 under loads. Preferably there are at least three pairs of vertically aligned bolt holes 1060 and one or more individual bolt holes 1060 located centrally along the height of the stem 1040.

The connector plate 1030 is provided with a plurality of holes and/or slots which pass through the connector plate 1030.

These are for use in securing the connector plate 1030 to the crossbar 1050 of the T-plate 1040 and for connecting the connector plate 1030 to an external building element via suitable components.

Connection components enable an exterior element to be connected to, aligned with and supported by the joists 1010. Preferred connection components are illustrated in the Figures but it will be recognised that different arrangements will be suitable based on different requirements and many suitable components are known in the art.

The connector plate 1030 may be provided with one or more sets of vertically aligned slots 1110. In use, each pair of slots receives a support component, such as an angled bracket 1120, on a front face of the connector plate 1030. The brackets 1120 have lugs 1125 matching the slots 1110 on the connector plate 1030. The lugs 1125 are pushed into the slots 1110 and the bracket 1120 is then pushed down to securely lock it in position. The brackets 1120 are sized and shaped such that, when in position, the top edges of each bracket 1120 are aligned with each other and with an upper surface of the joists 1010. When in place, each bracket 130 supports loads from above and transfers these loads into the joists 1010 via the T-plate assembly 1000.

One or more sets of holes are provided on the connector plate 1030 to enable the crossbar 1050 of the T-plate 1020 to be screwed/bolted to the connector plate 1030. Preferably there are two sets of four bolts holes, one set adjacent each end of the connector plate 1030, matching the holes 1055 on the crossbar 1050. In use, a connector 1130, preferably a thermally broken connector, is also screwed or bolted to the front face of the connector plate 1030 through the same holes 1055 when fixing the T-plate 1020 to the connector plate 1030.

Each connector 1130 preferably comprises a thermal break 1140 such as the one described in UK patent application GB2462830. The thermal break 1140 is bolted or screwed to the T-plate assembly 1000 through the holes 1055, preferably from the rear at the same time as the crossbar 1050 is bolted/screwed to the connector plate 1030, and using the same bolts/screws. The thermal break 1140 transfers the weight of any attached external element into the joists 1010 and also acts as a thermal barrier between the interior and exterior of the building, preventing the creation of a thermal bridge. An extension bracket 1150 is bolted to the thermal break 1140 and extends the connector 1130. The size of the extension bracket 1150 is selected so that the connector 1130 spans the full depth of the building envelope. An external element is bolted to the extension bracket 1150.

The connectors 1130 are sized and shaped such that, when in position, a top edge of each connector 1130 is aligned with the top edges of the brackets 1120. If required, the extension bracket 1150 is raked at an upwards angle to place the top edge of the extension bracket 1150 in the desired position. As well as supporting the weight of an external element, each connector 1130 therefore also support loads from above and transfers these loads into the joists 1010.

Floor decking, such as those described above in connection with Figures 6, 7 and 11, is placed on top of the brackets 1120 and connectors 1130. The decking also extends over the joists and creates a bridge between the interior of the building and the exterior element, ensuring a smooth transition between the two. The decking extends the full width of an opening made in the building envelope. The decking is made from a non-thermally conductive material to prevent the creation of a thermal bridge.

When the decking is in place, it can be used as a baseline for creating an interior floor surface 670 on top of the joists 1010. For example, a layer of chipboard flooring the same thickness as the decking can be laid over the joists 1010 to create a level floor.

Figures 14 and 15 show details of an extension bracket 1500 which may be used as the extension bracket 220, 650, 1150 illustrated in Figures 4, 10 and 12.

As previously described, the extension bracket 1500 extends a connector fixed to an internal building element (e.g. a concrete slab or timber joist) so that the connector spans the depth of the building envelope. This enables the connector to be easily adapted to be useful with many different designs of building.

Optionally, as depicted in Figures 14 and 15, the extension bracket 1500 is raked at an upwards angle to a desired height. Alternatively, the extension bracket 1500 has a level upper surface as shown on the extension bracket 220 of Figure 4.

The extension bracket 1500 includes a rear plate 1510. In use, the rear plate 1510 is connected to a cast-in plate 100 or connector plate 520, 1030, preferably via an intervening thermal break 210, 640, 1140. The rear plate 1510 has a plurality of holes 1520, preferably four, to enable the bracket 1500 to be connected to the thermal break with bolts 1525 or other suitable fasteners.

The extension bracket also comprises a front plate 1530. In use, the front plate 1530 is connected to an external building element such as a balcony. The front plate 1530 has a plurality of holes 1540, preferably four, to enable the bracket 1500 to be connected to the external element with bolts or other suitable fasteners.

The holes 1520 in the rear plate 1510 and the holes 1540 in the front plate 1530 are slotted by approximately 20mm to permit alignment of the extension bracket 1500 relative to connected components. In Figures 14 and 15, the rear plate holes 1520 are slotted vertically to permit vertical alignment of the extension bracket 1500 and the front plate holes 1540 are slotted horizontally to permit horizontal alignment of the extension bracket 1500. In general, the slots in the rear plate holes 1520 are parallel with each other and at right angles to the slots in the front plate holes 1540.

Slidable plates 1545 are located against the rear face of the front plate 1530. Each slidable plate has a pair of holes which are spaced apart by the distance between fastener holes in the exterior element which is to be attached to the extension bracket 1500. The holes in each slidable plate 1545 are aligned with pairs of slotted holes 1540 in the front plate 1530 and support fasteners 1525 passed through the front plate holes 1540. The slidable plates 1545 ensure that pairs of fasteners 1525 move in tandem, simplifying the task of aligning and attaching an exterior building element to the extension bracket 1500. The slidable plates 1545 also help prevent the fasteners from being pulled through the front plate holes 1540 by the weight of the exterior building element.

It is possible to fix the previously described cast-in plate 100 and connector plates 520, 1030 to interior building elements with high positional accuracy and the plates will typically be well aligned with the interior elements. The additional alignment opportunities provided by the slotted holes 1520, 1540 in the extension bracket 1500 permit precise levelling, particularly in situations where it is the interior elements that are not quite level.

The rear plate 1510 and front plate 1530 are joined by an angled bracket 1550, which rises upwards between the rear plate 1510 and front plate 1530 to transfer loads back into the interior building element. The angled bracket 1550 has holes cut into it to allow the slidable plates 1545 to slide freely. A top surface 1560 of the extension bracket 1500 is provided with water stop bead 1570 to prevent water from penetrating the building envelope.

Claims

CLAIMS :

1. A linkage for enabling connection of an interior building element and an exterior building element, the linkage comprising a linkage plate securable to one of the interior building element and the exterior building element, the linkage plate having a plurality of connector holes for receiving a plurality of connectors, the connector holes arranged to align the received connectors with each other for connection to the other of the interior building element and the exterior building element.

2. The linkage of claim 1, the linkage plate further comprising a plurality of anchor holes, each anchor hole for receiving and securing an anchor extending away from a rear surface of the linkage plate, thereby enabling the linkage to be fixedly cast into a face of a concrete building element in use with the plurality of anchors located inside the concrete building element.

3. The linkage of claim 1 or claim 2, the linkage further comprising a plurality of anchors extending away from a rear surface of the linkage plate, each anchor received by and secured within an anchor hole in the linkage plate, thereby enabling the linkage to be fixedly cast into a face of a concrete building element with the plurality of anchors located inside the concrete building element.

4. The linkage of claim 2 or claim 3 wherein a front surface of the linkage plate is substantially flat, and the anchors do not extend past the front face of the linkage plate.

5. The linkage of any of claims 2 to 4 wherein the rear surface of the linkage plate further includes a plurality of covers, each cover covering at least one connector hole, to prevent ingress of concrete slurry into the covered connector hole .

6. The linkage of any of claims 2 to 5 wherein at least some of the anchors are each secured to the linkage plate via a female coupling located in an anchor hole, the female coupling having a fastener hole for receiving a fastener to secure a connector to the linkage plate and to the associated anchor.

7. The linkage of claim 1 further comprising a plurality of strap plates arranged at right angles to the linkage plate, each strap plate comprising a plurality of fastener holes for receiving fasteners to secure the strap plate to a first surface of a building element, the linkage plate comprising a plurality of fastener holes for receiving fasteners to secure the linkage plate to a second surface of the building element, perpendicular to the first surface.

8. The linkage of claim 7 wherein the linkage plate comprises a plurality of sets of strap plate holes and each strap plate comprises a set of corresponding lugs and wherein the lugs are received by the strap plate holes and welded to secure the strap plates to the linkage plate.

9. The linkage of claim 7 or claim 8 wherein the fastener holes in each strap plate are arranged to enable fasteners to be inserted so that no two fasteners are in line with each other in a direction perpendicular to the second surface of the building element.

10. The linkage of any of claims 7 to 9 wherein the building element is a reinforced concrete slab and wherein adjacent fastener holes in each strap plate are spaced apart in a direction parallel with the second surface by a distance equal to half the distance between reinforcing bars in the reinforced concrete slab.

11. The linkage of any of claims 7 to 10 wherein each strap plate has a profile that is narrower near the junction between the strap plate and the linkage plate then widens in a direction parallel with the second surface.

12. The linkage of any of claims 7 to 10 wherein each strap plate has a profile in the shape of a T, the stem of the T being attached to the linkage plate.

13. The linkage of claim 1 further comprising a plurality of T-plates, each T-plate comprising a cross-piece plate and a stem plate fixed together at right angles to each other, the cross-piece plate being secured flat against the linkage plate and the stem plate extending at a right angle away from the linkage plate, the stem plate having a plurality of fastener holes for receiving fasteners to secure the stem to a building element.

14. The linkage of claim 13 wherein the building element comprises a plurality of pairs of wooden joists and wherein, in use, each stem plate is sandwiched between a pair of wooden joists to secure the stem to the building element.

15. The linkage of claim 14 wherein each fastener hole in a stem plate is surrounded by a raised, sharpened edge.

16. The linkage of claim 15 wherein each fastener hole in a stem plate has a diameter larger than the fastener.

17. The linkage of claim 15 or claim 16 wherein each fastener received by a fastener hole in a stem plate comprises a bolt and, in use, a clamping force is applied to sandwich each stem plate between a pair of wooden joists by washers located between each joist and nuts screwed onto the ends of each bolt.

18. The linkage of claim 17 wherein the fastener holes in the stem plate are arranged to distribute the clamping force evenly.

19. The linkage of any of claims 13 to 18 wherein each crosspiece plate comprises a plurality of fastener holes which are aligned with connector holes, the aligned holes for receiving fasteners to secure the cross-piece plate to one face of the linkage plate and a connector to the opposite face of the linkage plate.

20. The linkage of any preceding claim wherein at least one connector received by the linkage plate comprises a thermal break.

21. The linkage of any preceding claim wherein at least one connector received by the linkage plate comprises a bracket to support a floor surface placed above the bracket.

22. The linkage of any preceding claim wherein at least one connector received by the linkage plate comprises an extension bracket to extend the connector to span the depth of a building envelope.

23. The linkage of claim 22 wherein the extension bracket comprises a first plate having a first plurality of fastener holes for receiving fasteners to connect the extension bracket to the linkage plate, the first plurality of fastener holes being slotted in a first direction, and a second plate having a second plurality of fastener holes for receiving fasteners to connect the extension bracket to a building element, the second plurality of fastener holes being slotted in a second direction perpendicular to the first direction.

24. The linkage of claim 23 wherein a thermal break is connected between the extension bracket and the linkage plate.

25. The linkage of any preceding claim wherein each end of the linkage plate has a jigsaw profile to enable a plurality of linkage plates to be connected and aligned with each other.