GB2393978A

GB2393978A - Wall tie connection for securing an outer masonry wall to a steel frame

Info

Publication number: GB2393978A
Application number: GB0323401A
Authority: GB
Inventors: Graham Law
Original assignee: Ancon Ltd
Current assignee: Leviat Ltd
Priority date: 2002-10-10
Filing date: 2003-10-07
Publication date: 2004-04-14
Also published as: GB0323401D0; IE20030741A1; GB0223511D0

Abstract

A connection comprises an anchor (12, 212), a fastener (36) and spacer means (14, 16). The anchor may be a channel section having a longitudinal extending slot defined by flanges (20). A first end of a wall tie (22, 222) may engage the anchor channel by twisting and a second end (28, 228) may be embedded in brickwork (102). The fastener may be a self tapping screw which engages with the steel frame. The spacer means may include at least two legs (214, 216) which project from the anchor and engage against the metal frame when the fastener is tightened.

Description

À Or 1 2393978

1 STEEL FRAME TIE

3 This invention relates to structural connections, 4 and relates more particularly but not exclusively to 5 wall ties for securing an outer wall of brickwork to 6 an inner metal substructure of a building, such as 7 steel studding. This invention also relates 8 particularly but not exclusively to a method of 9 fabricating a building which has a metal 10 substructure and is brick-clad.

12 Steel-framed housing is widely known, and current 13 levels of use of steel-framed housing in the United 14 Kingdom are expected to increase within the 15 foreseeable future. Steel-framed housing has the 16 advantages of allowing precision fabrication in a 17 factory, i.e. centralized fabrication within a 18 controlled environment remote from the eventual site 19 of the housing, which allows optimization of 20 fabrication procedures. Conversely, prefabrication 21 allows increased rates of construction on site' and

r 1 it has been found that construction times can be 2 reduced by half.

4 In steel-framed housing, wall ties are required to 5 tie the outer brickwork cladding of the housing to 6 the vertical steel members of the steel frame. Wall 7 ties in steel-framed housing are also required to 8 hold cavity insulation in place, such insulation 9 typically being rigid and having a thickness in the 10 range of 35 - 50 mm. In steel-framed housing, the 11 vertical steel members are typically formed as 12 vertically mounted channels or Z sections which are 13 mutually horizontally spaced at appropriate 14 intervals, typically 600 mm. One manufacturer's 15 system uses channels typically measuring 90 mm wide 16 and 31 mm deep, with the channel steel having a 17 thickness of about 1.2 mm, but other dimensions are 18 also used.

20 It is an object of the invention to provide improved 21 structural connections, and to provide an improved 22 method of prefabricating a building.

24 According to a first aspect of the present invention 25 there is provided a structural connection 26 particularly but not exclusively for enabling the 27 securing of an outer wall of brickwork or blockwork 28 to an inner steel frame, the structural connection 29 comprising an anchorage means for a wall tie, 30 fastening means for fastening the anchorage means to 31 the steel frame, and spacer means for spacing the 32 anchorage means substantially at a predetermined

1 distance from the steel frame when the anchorage 2 means is fastened to the steel frame by the 3 fastening means.

5 The anchorage means may comprise a length of channel 6 section having a longitudinal slot or other opening 7 enabling insertion into the interior of the channel 8 section of part of a wall tie when the wall tie is 9 in a first alignment relative to the channel section 10 while preventing withdrawal of the inserted part of 11 the wall tie when the wall tie is in a second 12 alignment relative to the channel section. The 13 longitudinal slot may have lips which engage with 14 slots on the wall tie to prevent withdrawal of the 15 wall tie. The lips may be locally deformed at the 16 end to restrain the wall tie in the channel.

18 The spacer means may comprise a plurality of legs or 19 other projections preferably integral with or 20 permanently secured to the anchorage means. The 21 legs or other projections may be welded to the 22 anchorage means, or may be attached to the anchorage 23 means by any suitable means, for example by brazing, 24 adhesive bonding, interference fit or screw thread 25 connection. The legs or other projections may be 26 formed integrally with the anchorage means by 27 casting or stamping and bending, or by any other 28 suitable means. The legs or other projections are 29 preferably formed to be insulation-piercing. The 30 spacer means preferably provides at least three 31 points of contact with the steel frame when the 32 anchorage means is fastened to the steel frame, such

1 contact conveniently being achieved by providing at 2 least three legs or other projections. The legs or 3 other projections may be secured to the length of 4 channel section constituting the anchorage means in 5 such a manner as to close the opposite ends of the 6 length of channel. Alternatively, the legs or other 7 projections may be secured to the length of channel 8 section in such a way as to allow the inserted part 9 of the wall tie to slide within the channel section 10 past the legs or other projections. In a preferred 11 embodiment the spacer means comprises two or more 12 pairs of legs. Preferably the legs of each pair of 13 legs are spaced transversely with respect to the 14 length of channel section. Each pair of legs may be 15 formed from a u-shaped member inserted through 16 apertures in the length of channel sections and 17 secured to the channel section by, for example, 18 welding, brazing or bonding.

20 The fastening means may comprise any suitable form 21 of fastener, and in a particularly simple form, the 22 fastening means comprises a single self-drilling and 23 self-tapping screw passing through a suitably 24 dimensioned and preferably central hole in the 25 anchorage means, the screw being of sufficient 26 length to reach and penetrate the steel frame to an 27 adequate depth despite the distancing effect of the 28 spacer means.

30 According to a second aspect of the present 31 invention there is provided a wall tie assembly for 32 securing an outer wall of brickwork or blockwork to

1 an inner steel frame, the wall tie assembly 2 comprising a structural connection according to the 3 first aspect of the present invention, in 4 combination with a wall tie adapted at an inner end 5 thereof to be anchored in the anchorage means and 6 adapted at an outer end thereof to be embedded in 7 the brickwork.

9 The wall tie may comprise the non-channel component 10 of any suitable channel-anchored wall tie system, 11 the inner end of the wall tie being, for example, 12 dovetailed or side-slotted or mushroom-ended for 13 anchorage in a channel section, and the outer end of 14 the wall tie being shaped for embedment in a mortar 15 course of the brickwork. The wall tie preferably 16 incorporates a drip-promoting means intermediate the 17 inner and outer ends for inhibiting the passage of 18 moisture along the wall tie. Suitable forms of wall 19 tie are shown in Figure 7 of GB2255358A (the wall 20 tie assemblies disclosed therein being per se 21 unusable on steel-framed buildings).

23 According to a third aspect of the present invention 24 there is provided a method of fabricating a building 25 clad in brickwork or blockwork, the method 26 comprising the steps of assembling a metal 27 substructure of a building, providing a plurality of 28 structural connections according to the first aspect 29 of the present invention, fastening individual ones 30 of the structural connections to the substructure 31 frame at respective selected locations thereon, 32 progressively assembling a cladding of brickwork or

l Clockwork around the substructure by successive 2 superimposition of bricks or blocks, and as an upper 3 edge of the cladding approaches a given selected 4 location during assembly of the cladding, anchoring 5 the inner end of a wall tie in the anchorage means 6 of the structural connection fastened to the 7 substructure at that selected location and embedding 8 the outer end of the wall tie in an adjacent portion 9 of the cladding.

11 The entire plurality of structural connections may 12 be fastened to the substructure prior to commencing 13 assembly of the cladding, or individual ones of the 14 structural connections may be fastened to the 15 substructure immediately prior to their required 16 incorporation into the building, or some at least of 17 the plurality of structural connections may be 18 fastened to the substructure after commencement of 19 cladding assembly but prior to their being 20 individually required. The structural connections 21 are preferably fastened so that the slots extend 22 vertically. The structural connections may be 23 provided in discrete lengths or may be provided as 24 continuous lengths extending substantially over the 25 height of the cladding.

27 Slabs or mats of thermal insulation can be placed 28 between the core and the cladding, the insulation 29 preferably being secured in place by being clamped 30 against the substructure by the anchorage means of 31 the structural connections. The spacer means of the 32 structural connection may pierce the insulation at

1 the respective location where the insulation is 2 clamped by that structural connection. Holding 3 clips may be attached to the structural connections 4 to assist in holding the insulation against the 5 substructure.

7 According to a fourth aspect of the present 8 invention there is provided a building which is 9 steel framed and brick clad, the building having 10 been fabricated by the method according to the third 11 aspect of the present inventions so as to 12 incorporate a plurality of wall tie assemblies 13 according to the second aspect of the present 14 invention, each said wall tie assembly comprising a 15 respective structural connection according to the 16 first aspect of the present invention.

18 Embodiments of the invention will now be described 19 by way of example, with reference to the 20 accompanying drawings wherein: 22 Figure 1 is a perspective view of a wall tie 23 assembly in accordance with a first embodiment of 24 the present invention; 26 Figures 2 and 3 are respectively an elevation and an 27 end view of a length of channel section forming part 28 of the wall tie assembly of Figure 1; 30 Figures 4 and 5 are respective plan views of two 31 complementary spacers forming an integral part of 32 the wall tie assembly of Figure 1;

1 Figure 6 is a plan view of a wall tie forming part 2 of the wall tie assembly of Figure 1; 3 Figure 7 is a side elevation of the wall tie 4 assembly of Figure 1 in use to tie brick cladding to 5 a steel frame; 7 Figure 8 is a perspective view of a wall tie 8 assembly in accordance with a second embodiment of 9 the present invention; 11 Figure 9 is a perspective view of the end of the 12 wall tie assembly of Figure 8 with an alternative 13 end detail; 15 Figures 10 and 11 are respectively an elevation and 16 an end view of a length of channel section forming 17 part of the wall tie assembly of Figure 8; 19 Figure 12 is a plan view of a wall tie forming part 20 of the wall tie assembly of Figure 8; 22 Figure 13 is a partial perspective view of the wall 23 tie assembly of Figure 8 in use to tie brick 24 cladding to a steel frame; and 26 Figures 14 and 15 are cross-sectional views of the 27 channel section of Figure 10 showing a holding clip 28 during and after installation respectively.

30 Referring first to Figures 1 to 6, a wall tie 31 assembly 10 in accordance with the invention 32 comprises a short length of channel section 12 to

1 respective opposite ends of which a single-legged 2 spacer 14 and a twolegged spacer 16 are welded (see 3 Figure 1). The spacers 14, 16 may be affixed by 4 other means, for example bolting, if so required.

5 The channel section 12 has a shallow rectangular C 6 shaped crosssection (see Figure 3) with a wide slot 7 18 in one major face. The slot 18 has inturned lips 8 20 which allow the anchoring of a wall tie 22 whose 9 inner end 24 is provided with side slots 26 10 dimensioned to be a sliding fit on the channel lips 11 20. The outer end 28 of the wall tie 22 is formed 12 with an axially elongated hole 30 to assist in the 13 embedment of the outer end 28 in the inter-brick 14 mortar of a brick wall (not shown in Figure 1 but 15 schematically illustrated in Figure 7). A full 16 width transverse downward projection 32 is formed in 17 the wall tie 22 inboard of the hole 30 but outboard 18 of the inner end 24 in order to encourage moisture 19 travelling inward along the wall tie 22 to drip off 20 the lowest level of the downward projection 32 and 21 thereby inhibit dampness reaching the interior of 22 the building.

24 A hole 34 which is centrally formed in the channel 25 section 12 allows the insertion of a fastening screw 26 36 by which the channel section 12 can be fastened 27 to the steel frame of a building, as will 28 subsequently be described with reference to Figure 29 7. The screw 36 is conveniently in the form of a 30 self-drilling, self-tapping screw of a kind known 31 per se, which can be directly inserted into 32 unprepared sheet steel. However any other fastener

1 suitable for engaging with a steel frame member may 2 - be used.

4 Referring now to Figures 4 and 5 in particular, 5 these Figures clearly show how the spacers 14 and 16 6 are complementary in shape, i.e. when nested, the 7 spacers 14 and 16 combine to form a rectangle such 8 that they can be cut from strip stock substantially 9 without wastage of metal. The spacer 14 has a 10 single central leg 38 with a pointed end 40. The 11 spacer 16 has a bilaterally spaced pair of legs 42 12 with each leg 42 having a respective pointed end 44.

13 The points 40 and 44 facilitate penetration of 14 insulation by the spacer legs 38 and 42, as will 15 subsequently be detailed with reference to Figure 7.

16 The components 12, 14, 16 and 22 are conveniently 17 formed by known techniques from sheet metal, the 18 sheet metal from which the channel 12 is formed 19 preferably having a thickness of about 1.5 mm, the 20 sheet metal from which the spacers 14 and 16 are 21 formed preferably having a thickness of about 2 mm, 22 and the sheet metal from which the wall tie 22 is 23 formed preferably having a thickness of about 2 mm.

24 Typically the channel section 34 has a length of 80 25 or 90 mm, a width of 25 mm and a depth of 9 or 14 26 mm, while the tie 22 typically has a length of 120 27 mm and a width of 20 mm. The spacers 14, 16 28 typically have a length of 50 mm. However it is to 29 be understood that the dimensions are given by way 30 of example only, and the components may be provided 31 in any suitable dimensions to suit the

1 constructional dimensions of the building in which 2 they are to be used.

4 The material or materials from which the components 5 of the wall tie assembly are formed can be stainless 6 steel, or some other suitable steel which may be 7 galvanized, phosphated, or coated in a manner to 8 obviate or mitigate corrosion. Other metals or 9 alloys may also be used, particularly if the 10 building frame is of a material other than steel, 11 for example aluminium alloy.

13 Referring now to Figure 7, this is a simplified and 14 semi-schematic diagram illustrating the installation 15 and use of a wall tie assembly 10 (as previously 16 detailed with reference to Figures 1 to 6). In 17 Figure 7, the reference loo designates part of the 18 metal substructure of a building (the remainder of 19 which is not shown). In the example the 20 substructure is a frame of steel studding, but the 21 substructure can be any metal substructure, frame or 22 core. The term "steel frame" when used in the 23 specification is to be understood to encompass any

24 metal frame or substructure.

26 A short distance outside the steel frame 100 (to the 27 right of the steel frame 100 as viewed in Figure 1) 28 is brickwork cladding 102 comprising successively 29 applied courses of bricks 104, 106 and 108 (only the 30 upper part of the course 104 being depicted in 31 Figure 7). Conventional layers of mortar 110 and 32 112 are applied between the successive courses 104,

1 106 and 108. The term brick is to be understood to 2 include any blocktype building component.

4 It is assumed for the purpose of the exemplary wall 5 tie installation illustrated in Figure 7 that the 6 brickwork cladding 102 is to be tied to the steel 7 frame 100 at a location which is selected to be 8 vertically between the courses 104 and 106, the 9 location also being selected to be horizontally 10 located in the vertical sectional plane depicted in 11 Figure 7. Immediately prior to installation of the 12 wall tie assembly 10, it is assumed that either the 13 cladding 102 is entirely absent, or that the course 14 104 has been laid but the courses 106 and 108 have 15 not yet been laid. It is also assumed that a slab 16 114 of rigid thermal insulation is to be installed 17 in the cavity between the steel frame 100 and the 18 cladding 102.

20 Wall tie installation commences with the provision 21 of a structural connection comprising the integral 22 assembly of the channel section 12 and the spacer 23 assembly comprising the rigidly-attached spacer legs 24 14 and 16 ( i. e. the structural connection consists 25 of the wall tie assembly 10 minus the wall tie 22 26 and minus the fastening screw 36). Installation 27 commences with the emplacement of the insulation 28 slab 114 against the exposed exterior of the steel 29 frame 100 at the intended location of the 30 insulation.

1 The structural connection is then placed against the 2 exterior surface of the emplaced insulation slab 114 3 (the right side of the slab 114 as viewed in Figure 4 7), the structural connection being vertically 5 located such that the channel slot 18 vertically 6 overlaps the top of the course 104 wherein the wall 7 tie 22 is intended eventually to be embedded (as 8 will subsequently be explained in detail). The 9 structural connection is then forced inwards 10 (leftwards as viewed in Figure 7) such that the 11 points 40 and 44 penetrate the insulation slab 114, 12 followed by the spacer legs 38 and 42, until the 13 points 40 and 44 come into contact with the exterior 14 surface of the steel frame 100 (the rightward 15 surface as viewed in Figure 7). It is to be noted 16 that whereas the spacer legs 38 and 42 readily 17 penetrate the insulation slab 114, there is 18 substantially no penetration of the steel frame 100 19 by the spacer legs 38 and 42. Although the ends of 20 the spacer legs 38, 42 are shown as points 40, 44, 21 it is envisaged that the ends may be rounded, flat 22 or square.

24 The first stage of installation is completed by 25 providing the fastening screw 36 (of suitable 26 dimensions), pushing the screw 36 through the 27 central hole 34 in the back of the channel section 28 12 and through the underlying insulation until the 29 point of the screw 36 contacts the exterior surface 30 of the steel frame 100, and thereafter applying a 31 suitable combination of torque and axial pressure to 32 the screw 36 such that the screw 36 initially self

1 drills a hole into the steel frame 100 and then 2 self-taps that hole, with the screw 36 subsequently 3 being screwed into that now-threaded hole finally to 4 hold the structural connection firmly against the 5 steel frame 100. The spacers 14 and 16 hold the 6 channel section 12 away from the steel frame 100 by 7 about the thickness of the insulation slab 114 such 8 that the insulation is not crushed flat by the 9 installation of the wall tie assembly. The points 10 40 and 44 provide three-point contact with the steel 11 frame 100 such that although only a single fastening 12 screw 36 is utilized, the channel section 12 is 13 firmly fastened in a fully stable position. The 14 points 40 and 44 may indent the steel frame 100 just 15 sufficiently to enhance stability of position by 16 inhibiting skidding of the spacer legs 38 and 42 17 across the outer surface of the steel frame 100.

19 Once the structural connection is securely installed 20 (as detailed above), wall tie installation is 21 completed by the additional steps of providing an 22 initially separate wall tie 22, holding the tie 22 23 longitudinally horizontal but turned so that its 24 major faces are substantially vertical, placing the 25 inner end 24 of the wall tie 22 through the slot 18 26 to be located inside the channel section 12, and 27 turning the tie 22 through a quarter-turn until the 28 slots 26 engage around the lips 20 of the slot 18 of 29 the channel section 12. The quarter-turn is 30 necessarily in a direction which causes the 31 projection 32 to point downwards at the finish of 32 installation in order to provide effective shedding

1 of inward-travelling moisture. Alternatively, the 2 wall tie 22 could be double-cranked such as to form 3 a bi-directional drip which will be functionally 4 effective whichever face of the member 22 finishes 5 uppermost. 7 Finally, the mortar layer 110 is applied to the 8 upper face of the brickwork course 104, and the 9 outer end 28 of the tie 22 is embedded in the mortar 10 of this layer 110, "hereafter the next brickwork 11 course 106 is laid on top.

13 Compared to full-height channels, the channel 14 section 12 is relatively short, with consequent 15 savings of metal. The channel section 12 is only 16 long enough to make its installation location 17 minimally critical, i.e. the installation location 18 needs only to vertically overlap the top of the 19 brickwork course 104. However, by making the length 20 of the channel section 12 just greater than the 21 vertical separation of two successive mortar layers, 22 the cladding 102 could, if desired, be tied on both 23 vertical sides of a given course by anchoring two 24 wall ties at vertically spaced locations in a single 25 channel section, thereby to form a double wall tie 26 assembly. For example, with reference to Figure 7, 27 a second wall tie (not shown) could be anchored in 28 the upper end of the channel section 12 and embedded 29 in the mortar layer 112 on the other side of the 30 brickwork course 106 from the mortar layer 110 in 31 which the wall tie 22 is embedded.

1 Referring now to Figures 8 to 12, a second 2 embodiment of a wall tie assembly 210 in accordance 3 with the invention is shown. The assembly 210 and 4 its components function in the same manner as the 5 wall tie assembly 10 described above with reference 6 to Figures 1 to 7 and its method of use in steel 7 frame constructions, being the same, will not be 8 described here. However the method of fabrication 9 differs slightly.

11 The wall tie assembly 210 comprises a short length 12 of channel section 212 near respective opposite ends 13 of which spacers 214, 216 are fixed. Each pair of 14 spacers 214, 216 is formed from a U-shaped rod or 15 wire 218 which is inserted through apertures 240 in 16 the channel section 212. Typically the spacers 214, 17 216 are of 3 mm diameter and have flat or pointed 18 ends to pierce the insulation. If required the ends 19 of the spacers 214, 216 can be provided with 20 insulating caps to reduce cold bridging. The rod 21 218 may be affixed by welding, brazing, adhesive 22 bonding or any other suitable means. The channel 23 section 212 has a shallow rectangular C-shaped 24 cross-section (see Figure 11) with a wide slot 18 in 25 one major face. The slot 18 is provided at each 26 side thereof with inturned lips 20 which allow the 27 anchoring of a wall tie 222 whose inner end 224 is 28 provided with side slots 226 dimensioned to be a 29 sliding fit on the channel lips 20. The inner end 30 224 is also provided with a cut-out portion to 31 enable the tie to slide along the channel over the 32 heads of the screws 36. The outer end 228 of the

1 wall tie 222 is formed with a plurality of holes 230 2 and recesses 234 to assist in the embedment of the 3 outer end 228 in the inter-brick mortar of a brick 4 wall, as described above with reference to Figure 7.

5 A full-width transverse downward projection 232 6 forms a drip in the wall tie 222 as described above 7 with reference to Figure 6.

9 In the embodiment of Figure 8 the end portions 238 10 of the lips 20 of the channel section 212 are bent 11 down to prevent the wall tie 222 from sliding out of 12 the channel slot 18, since the lugs 236 formed at 13 the inner end 224 of the wall tie 222 are too large 14 to pass the bent end portions 238. In the 15 embodiment of Figure 9 the bent end portions 238 are 16 replaced by depressed portions 239 which serve the 17 same function. Alternatively, the end portions 238 18 can be deformed upwards or downwards so the side 19 slots 226 in the wall tie cannot pass the end 20 portions 238.

22 A hole 34 which is centrally formed in the channel 23 section 212 allows the insertion of a fastening 24 screw 36 by which the channel section 12 can be 25 fastened to the steel frame of a building, as 26 described above with reference to Figure 7.

28 The material or materials from which the components 29 of the wall tie assembly are formed can be stainless 30 steel, or some other suitable steel which may be 31 galvanized, phosphated, or coated in a manner to 32 obviate or mitigate corrosion. Other metals or

1 alloys may also be used, particularly if the 2 building frame is of a material other than steel, 3 for example aluminium alloy.

5 Figure 13 illustrates a further embodiment of the 6 invention. The channel section 312, which is 7 similar in all other respects to the channel 212 8 shown in Figures 8 to 12, is provided in a 9 continuous length and self drill self tap screws 36 10 are provided, typically at 450 mm centres, through 11 pre-drilled holes 34 to fix the channel 312 and the 12 insulation material 114 to the steel studding 100.

13 Spacers 214, 216 are secured to the channel 312, 14 typically at 225 mm centres. Ties 22, 222 are 15 installed at the spacing required by local 16 conditions and building regulations. The system 17 offers the advantage that the channel 312 can be 18 fixed well in advance of the construction of the 19 brickwork or blockwork 102.

21 In certain circumstances the vertical joints between 22 adjacent sheets of insulation material 114 may 23 coincide with the positions of the vertical channel 24 sections 312. In such cases the channel sections 25 may not be wide enough to hold the sheets during 26 installation, and it has been found beneficial to 27 provide holding clips 250, as shown in Figures 14 28 and 15, which engage in a snap fit manner around the 29 channel section 312. The flanges of the holding 30 clips serve to hold the edges of the sheets of 31 insulation material 114 against the steel studding 32 100. To fit the holding clip 250, it is brought up

1 against the channel 312 to the position shown in 2 Figure 14. The clip 250 is then pressed onto the 3 channel 312 until it is in the position shown in 4 Figure 15, in which the flanges of the clip 250 are 5 coplanar with the web of the channel 312, so that 6 both the flanges of the clip 250 and the web of the 7 channel 312 abut the sheets of insulation material 8 114. The clips 250 increase the effective width of 9 the channel section 312. The clips 250 may be used 10 to aid the fixing of the channels over joints in the 11 sheets of insulation. Once the channels 312 are 12 fixed they may be removed and reused, if required.

14 While certain alternative forms of the invention 15 have been described above, the invention is not 16 restricted thereto, and other modifications and 17 variations can be adopted without departing from the 18 scope of the invention.

Claims

1 CLAIMS

3 1. A structural connection for securing an outer 4 wall of brickwork or clockwork to an inner metal 5 frame, the structural connection comprising an 6 anchorage means for a wall tie, fastening means for 7 fastening the anchorage means to the steel frame, 8 and spacer means for spacing the anchorage means 9 substantially at a predetermined distance from the 10 steel frame when the anchorage means is fastened to 11 the steel frame by the fastening means.

13

2. A structural connection according to claim 1, 14 wherein the anchorage means comprises a length of 15 channel section having a longitudinal opening 16 enabling insertion into the interior of the channel 17 section of part of a wall tie when the wall tie is 18 in a first alignment relative to the channel section 19 while preventing withdrawal of the inserted part of 20 the wall tie when the wall tie is in a second 21 alignment relative to the channel section.

23

3. A structural connection according to claim 2, 24 wherein the longitudinal slot has lips which engage 25 with slots on the wall tie to prevent withdrawal of 26 the wall tie.

28

4. A structural connection according to claim 3, 29 wherein the lips are locally deformed at at least 30 one end of the length of channel section to restrain 31 the wall tie in the channel.

1

5. A structural connection according to any 2 preceding claim, wherein the spacer means comprises 3 a plurality of legs projecting from the anchorage 4 means in a direction substantially opposite to the 5 wall tie.

7

6. A structural connection according to claim 5, 8 wherein the legs comprise the legs of a U-shaped 9 member secured to the anchorage means.

11

7. A structural connection according to claim 6, 12 wherein legs of the U-shaped member extend through 13 apertures provided in the anchorage means.

15

8. A structural connection according to any of 16 claims 5 to 7, wherein the spacer means comprises 17 two or more pairs of legs.

19

9. A structural connection according to claim 8, 20 wherein the legs of each pair of legs are spaced 21 transversely with respect to the longitudinal length 22 of the anchorage means.

24

10. A structural connection according to any 25 preceding claim, wherein the fastening means 26 comprises one or more self-drilling and self-tapping 27 screws, each passing through a hole in the anchorage 28 means.

30

11. A wall tie assembly for securing an outer wall 31 of brickwork or Clockwork to an inner steel frame, 32 the wall tie assembly comprising a structural

1 connection according to any of claims 1 to 10 and 2 one or more wall ties adapted at an inner end 3 thereof to be anchored in the anchorage means and 4 adapted at an outer end thereof to be embedded in 5 the outer wall.

7

12. A wall tie assembly according to claim 11, 8 wherein the anchorage means comprises a length of 9 channel section having a longitudinal opening 10 enabling insertion into the interior of the channel 11 section of part of one of said wall ties when the 12 wall tie is in a first alignment relative to the 13 channel section while preventing withdrawal of the 14 inserted part of the wall tie when the wall tie is 15 in a second alignment relative to the channel 16 section.

18

13. A wall tie assembly according to claim 12, 19 wherein the wall tie has an inner end being 20 dovetailed or side-slotted or mushroom-ended for 21 anchorage in the channel section, and an outer end 22 being shaped for embedment in a mortar course of the 23 brickwork.

25

14. A wall tie assembly according to claim 12, 26 wherein the wall tie incorporates a drip-promoting 27 means intermediate the inner and outer ends for 28 inhibiting the passage of moisture along the wall 29 tie.

31

15. A method of fabricating a metal framed building 32 clad in brickwork or blockwork, the method

1 comprising the steps of assembling a metal 2 substructure of a building, providing a plurality of 3 structural connections according to any of claims 1 4 to 10, fastening individual ones of the structural 5 connections to the metal substructure at respective 6 selected locations thereon, progressively assembling 7 a cladding of brickwork or blockwork around the 8 substructure by successive superimposition of bricks 9 or blocks, and as an upper edge of the cladding 10 approaches a given selected location during assembly 11 of the cladding, anchoring the inner end of a wall 12 tie in the anchorage means of the structural 13 connection fastened to the metal substructure at 14 that selected location and embedding the outer end 15 of the wall tie in an adjacent portion of the 16 cladding. 18

16. The method of claim 15, wherein the entire 19 plurality of structural connections is fastened to 20 the steel frame prior to commencing assembly of the 21 cladding. 23

17. The method of claim 15 or 16, wherein the 24 anchorage means comprise lengths of channel section 25 having a longitudinal opening, and the structural 26 connections are fastened so that the longitudinal 27 openings extend vertically.

29

18. The method of claim 17, wherein the lengths of 30 channel section are fastened in discrete lengths.

1

19. The method of claim 17, wherein the lengths of 2 channel section extend substantially over the height 3 of the cladding.

5

20. The method of any of claims 15 to 19, wherein 6 slabs or mats of thermal insulation are placed 7 between the substructure and the cladding, the 8 insulation being secured in place by being clamped 9 against the substructure by the anchorage means of 10 the structural connections.

12

21. The method of claim 20, wherein the spacer 13 means of the structural connection pierces the 14 insulation at the respective location where the 15 insulation is clamped by that structural connection.

17

22. A building having a brick clad substructure 18 fabricated by the method according to any of claims 19 15 to 21, including a plurality of wall tie 20 assemblies according to any of claims 11 to 14.