Cavity wall ties and methods of installing cavity wall ties

Abstract

A cavity wall tie includes an elongate tie member (12) to bridge a cavity in a cavity wall and a nail holder (14) attached to the elongate tie member. The nail holder (14) has a passage (24) through which, in use, a nail is driven to secure the elongate tie member to a leaf of a cavity wall. The cavity wall tie (10) is securable to a leaf of a cavity wall by a nail fired from a nail gun and the cavity wall tie is configured to be located on a nosepiece of a nail gun for offering the cavity wall tie up a substrate of the cavity wall and provide an internally disposed seat (25) for the head of the nail.

Description

Field of the Invention

[0001] The invention relates to cavity wall ties and methods of installing cavity wall ties.Background to the Invention

[0002] Cavity wall ties are unseen components that tie the internal and external leaves of a cavity wall together. Cavity wall ties are added to a cavity wall during construction. The ends of the ties may be bedded into the mortar bed at regular intervals. Cavity wall ties span the cavity, tying the load-bearing inner leaf to the outer leaf. Cavity wall ties impart stability to the outer leaf, holding the wall in place. They are also designed to accommodate small movements from temperature fluctuations, and prevent outside water transfer.Summary of the Invention

[0003] The invention provides a cavity wall tie as specified in claim 1.

[0004] The invention also includes a cavity wall tie system as specified in claim 10.

[0005] The invention also includes a cavity wall as specified in claim 11.

[0006] The invention also includes a method of installing a cavity wall tie as specified in claim 12.Brief Description of the Drawings

[0007] In order that the invention may be well understood, some examples thereof will now be described with reference to the drawings in which: Figure 1 is a schematic side view of a cavity wall tie; Figure 2 is schematic view from above of the cavity wall tie of Figure 1; Figure 3 is a schematic illustration of the cavity wall tie of Figures 1 and 2 installed in a partially completed cavity wall; Figure 4 is an enlarged schematic illustration of the cavity wall tie of Figures 1 and 2 installed in a partially completed cavity wall; Figure 5 is a schematic illustration of a method of installing the cavity wall tie of Figures 1 and 2 using a nail gun; Figure 6 is a perspective view of an example of a sleeve fitting for a cavity wall tie as shown in Figures 1 and 2; Figure 7 is a section on line VII-VII in Figure 6; Figure 8 is a section on line VIII-VIII in Figure 7; and Figure 9 shows a front elevation of an example of a sleeve holder and elongate tie member that may be used with a sleeve fitting similar to, or the same as, the sleeve fitting shown in Figures 6 to 8; and Figure 10 is a section on line X - X in Figure 9. Detailed Description

[0008] Referring to Figures 1 and 2, a cavity wall tie 10 comprises an elongate tie member 12 to at least partially bridge a cavity in a cavity wall and a nail holder comprising a sleeve holder 14 attached to the elongate tie member. The sleeve holder 14 extends laterally of the elongate tie member 12 and has an opening 16 through which, in use, a nail is driven to secure the elongate tie member to a leaf of a cavity wall. The sleeve holder 14 may take the form of an annular member disposed at a first end region 18 of the elongate tie member 12. The sleeve holder 14 may be a separate member secured to the first end region of the elongate tie 12 member by, for example, welding. Alternatively, the elongate tie member 12 and sleeve holder 14 may be a one-piece construction with the sleeve holder formed by a deformation process.

[0009] The nail holder further comprises a sleeve fitting 20 held by the sleeve holder 14. The sleeve fitting 20 comprises an elongate plastics sleeve 22 having a longitudinally extending cavity 24 through which, in use, the nail is driven to pass through the opening 16 in sleeve holder 14 to secure the elongate tie member 12 to a leaf of a cavity wall. A seat 25 for the head of a masonry nail is provided within the longitudinally extending cavity 24. The seat 25 may, for example, be formed by a change in diameter of the longitudinally extending cavity 24, in which case the longitudinally extending cavity comprises a relatively narrower diameter section disposed at the downstream end of the elongate plastics sleeve 22.

[0010] The sleeve fitting 20 may further comprise a flange 26. The sleeve holder 14 is fitted to a first end region 28 of the elongate plastics sleeve 22 and the flange 26 is disposed at a second end region 30 of the elongate plastics sleeve. The first end region 28 of the elongate plastics sleeve 22 may extend through the opening 16 of the sleeve holder 14. A second end region 31 of the elongate tie member 12 extends through and beyond the flange 26. The second end region 31 includes a free end of the elongate tie member 12 that, in use, will overlie a brick or the like of a leaf of a cavity wall and in the finished wall will be embedded in the mortar that lies between that brick and the course of bricks above. The flange 26 may be provided with a slot 32 through which the elongate tie member 12 extends. The slot 32 may be configured to allow the elongate tie member 12 to flex, or deflect away from a nail gun when, in use, the cavity wall tie 10 is located on a nosepiece of the nail gun. In the illustrated example, the slot 32 is oblong with a length that extends generally radially outwardly of the axis of the longitudinally extending cavity 24.

[0011] The longitudinally extending cavity 24 extends from the flange 26 at the end region 31to the first end region 28 of the elongate plastics sleeve 22. The longitudinally extending cavity 24 may be closed at the first end region 28 or open such that the longitudinally extending cavity defines a continuous passage extending through the sleeve fitting 20.

[0012] The elongate tie member 12 may extend alongside the elongate plastics sleeve 22, spaced apart from the elongate plastics sleeve. The elongate tie member 12 may be disposed parallel to the outer surface of the elongate plastics sleeve 22. As shown in Figure 1, the elongate plastics sleeve 22 tapers outwardly from the first end region 28 to the second end region 30.

[0013] The flange 26 has a major surface 34 that faces away from the first end region 28 of the elongate plastics sleeve 22 and at least one resilient gripper 36 is provided on the major surface radially outwardly of the longitudinally extending cavity 24. The at least one resilient gripper may comprise a continuous annular member that is resiliently deformable to enable it to grip the side of a nosepiece of a nail gen that has been inserted into the longitudinally extending cavity 24 via the annular member. Alternatively, as shown in Figures 1 and 2, the at least one gripper may comprise a plurality of spaced apart projections 36 that project from the major surface 34. The resilient grippers may comprise a plurality of generally triangular projections 36. The triangular projections 36 each have a base attached to the major surface 34 and an apex that is disposed radially inwardly of the base so that the triangular projections 36 are inclined towards the centre of the longitudinally extending cavity 24 and partially overlie the longitudinally extending cavity. It will be appreciated that although in the illustrated example, the projections are shown as triangular elements, this is not essential and the profile of the projections may resemble an arch or have any other suitable configuration that allows passage and gripping of the side of a nosepiece of a nail gun.

[0014] Referring to Figure 3, a cavity wall 50 comprises an inner leaf 52 and an outer leaf 54. The outer leaf 54 is spaced from the inner leaf to define a cavity 56 therebetween. The width of the cavity 56 may be between 50 and 75mm. Each leaf 52, 54 is made up of a plurality of bricks, breeze or cinder blocks or the like. In the illustrated example, the leaves 52, 54 each comprise a plurality of bricks 58 with the bricks of each course separated from the bricks of adjacent courses by layers of mortar 60. Although not essential, an insulating or isolation layer 62 may be disposed in the cavity, typically against the inner leaf 52. The isolation layer 62 may be any known form of isolation material used in cavity walls, such as insulation board or a coated rockwool slab. A cavity wall tie 10 is secured to the inner leaf 52 by a masonry nail 64 fired from a nail gun and the elongate tie member 12 extends across the cavity 56 so that its free end lies over a brick 58A of the outer leaf ready to be embedded in a layer of mortar that will be applied to the upper surface of the brick 58A ahead of building up the next course of bricks.

[0015] As shown in more detail in Figure 4, the cavity wall tie 10 is secured to the inner leaf 52 by a masonry nail 64 that has been driven through the sleeve fitting 20 by a nail gun so that its leading end is fixed in the mortar 60 between two courses of bricks 58 of the inner leaf. The masonry nail 64 extends through the opening 16 in the sleeve holder 14. The head 66 of the masonry nail 64 is pressed against an opposing surface defined by the seat 25 provided within the longitudinally extending cavity 24 of the elongate plastics sleeve 22. The elongate plastics sleeve 22 extends through the isolation layer 62 towards the inner leaf 52 and the flange 26 presses against the major surface 62S of the isolation layer that faces away from the inner leaf towards the outer leaf 54. The elongate tie member 12 extends from the sleeve holder 14, which is disposed adjacent the inner leaf 52, and has its free end 31F disposed above an uppermost brick 58A of the unfinished outer leaf 54 ready to be embedded in a layer of mortar 70 (shown in dashed lines) that will be applied when the next course of the outer leaf is laid. It can be seen that the elongate tie member 12 substantially bridges the cavity 56 and that when the cavity wall 50 is complete, the combination of the masonry nail 64, nail holder and the elongate tie member 12 provides a physical connection between the inner and outer leaves 52, 54 that bridges the cavity. The relatively large diameter flange 26 assists in spreading the force applied by the masonry nail 64 over a relatively large area of the major surface 62S of the isolation layer 62.

[0016] As shown in schematically in Figure 5, the cavity wall tie 10 is configured so that it can be installed using a nail gun 100. Nail guns, or nailers, are power tools that will be well known to those skilled in the art and so will not be described in detail herein. As shown in Figure 5, the nail gun 100 comprises a nosepiece 102 mounted on a barrel 103. In use, the nosepiece 102 is pressed against a substrate into which a fastener is to be fired to position the fastener relative to the substrate and drive the nosepiece towards the body of nail gun to ready the nail gun for firing. A blade 104 is disposed within the barrel 103. The nail gun 100 includes a force provider 106 configured to drive the blade 104 against a fastener to apply a blow to the fastener in similar fashion to a hammer. The force provider 106 may, for example, be powder actuated or powered by compressed air or a combustion engine disposed within the body of the nail gun 100.

[0017] To install the cavity wall tie 10, the free end 102F of the nosepiece 102 is inserted into the longitudinally extending cavity 24 of the plastics sleeve 22 through the flange 26. The triangular projections 36 engage the outer surface of the nosepiece 102 to locate and centre the cavity wall tie 10 on the nosepiece while it is being offered up to the wall. Typically, there is a clearance between the internal wall of the elongate plastics sleeve 22 that defines the longitudinally extending cavity 24 and the outer surface of the nosepiece 102. The leading end of the plastics sleeve 22 is then pressed against the major surface 62S of the isolation layer 62 to locate the cavity wall tie 10 in a desired position relative to the inner leaf 52 and push the nosepiece 102 backwards towards the main body of the nail gun 100 to ready the nail gun for firing. On the operation of a trigger or firing button 108, the force provider 106 is activated to cause a heavy impact force to be applied to the head 66 of a masonry nail 64 by the blade 104, thereby driving the nail from the barrel 103 into the longitudinally extending cavity 24 of the elongate plastics sleeve 22 and forcing the leading end of the nail through the isolation layer 62 into the inner leaf 52 of the cavity wall 50. The cavity wall tie 10 is driven into the isolation layer 62 by the masonry nail 64 so that the elongate plastics sleeve 22 is disposed within the isolation layer 62, the nail head 66 is seated within the longitudinally extending cavity 24 against the seat 25, the flange 26 engages the major surface 62S of the isolation layer and the cavity wall tie 10 is secured to the inner leaf 52 by the masonry nail.

[0018] Figures 6 to 8 illustrate an example of a sleeve fitting 200 that may form a part of various examples of a cavity wall tie 10. The sleeve fitting 200 may for example be used with the elongate tie member 12 and sleeved holder 14 shown in Figures 1 and 2. The sleeve fitting 200 comprises an elongate plastics sleeve 202, which has a relatively large diameter flange 204 at one end. The plastics sleeve 202 has a longitudinally extending cavity, which in this example is a passage 206F / 206S that extends from a first, or free, end 208 of the plastics sleeve 202 to a second end 210 at which the flange 204 is located so that there is a continuous passage running through the sleeve fitting 200. The flange 204 is provided with a plurality of resilient grippers, which in the illustrated example take the form of triangular projections 214. The triangular projections 214 each have a base attached to or near the major surface 216 of the flange 204 that faces away from the first end 208 of the plastics sleeve 202 and are configured to overlie the longitudinally extending cavity 206F / 206S. As shown in Figure 6, the triangular projections 214 may be attached to the plastics sleeve 202 within the longitudinally extending cavity 206F / 206S The triangular projections 214 are configured to grip the outer surface of the nosepiece of a nail gun in similar fashion to the triangular projections 36 shown in Figure 5 in order to align the sleeve fitting 200 with and hold it on the nosepiece. As with the projections 36, it will be understood that it is not essential that the projections 214 have a triangular outline and in other examples the projections may have an outline that resembles an arch or any other configuration suitable for gripping the outer surface of a nosepiece of a nail gun.

[0019] The through-passage 206F / 206S may be a multi-diameter feature comprising a first, relatively smaller diameter, portion 206F at a first end region 202F of the elongate plastics sleeve 202 that extends from the first end 208 of the plastics sleeve 202 towards the flange 204 and a second, relatively larger diameter, portion 206S at a second end region 202S of the elongate plastics sleeve that extends from the smaller diameter portion 206F to the end 210 of the plastics sleeve. In the illustrated example, the relatively larger diameter 206S is stepped so that it comprises different diameter portions that are larger in diameter than the smaller diameter portion 206F. The portion of the larger diameter portion 206S closest to the flange 204 is sized to allow it to receive the nosepiece of a nail gun, preferably with clearance so that the engagement with the side of the sleeve fitting 200 with the nosepiece is at least substantially only via the triangular projections 214 and the change of diameter defines an annular step that limits insertion of the nosepiece into the though-passage 206F / 206S. In examples in which the larger diameter portion 206S has only one diameter, it is similarly sized to receive the nosepiece of a nail gun, preferably with an initial clearance, but has a taper that limits insertion of the nosepiece. The smaller diameter portion 206F of the through-passage 206 is typically sized to receive the shank of a nail the cavity wall tie is designed to be used with, allowing a small clearance for the nail shank so that the internal wall defining the smaller diameter portion 206F can act as a guide for the nail as it enters the surface of the substrate it is driven into.

[0020] As best seen in Figure 7, the first end region 202F of the elongate plastics sleeve 202 may be smaller in diameter than second end region 202S. This facilitates driving of the sleeve fitting 200 into a substrate such as the isolation layer 62 and reduces the amount of material needed to form the sleeve fitting. One of both of the first and second end regions 202F, 202S may be provided with external ribs 220 that extend in the lengthways direction of the elongate plastics sleeve 202. Optionally, these ribs 220 may have a generally triangular cross-section as shown in Figure 8. The ribs 220 may strengthen the walls of the elongate plastics sleeve 202 allowing it to be kept relatively thin and so reducing the amount of material needed to manufacture the sleeve fitting 200. The ribs 220 may also assist in anchoring the sleeve fitting 200 in the substrate by reducing the likelihood of the sleeve fitting rotating, or twisting relative to the nail.

[0021] The smaller diameter portion 206F of the through-passage 206 may be extended into the larger diameter portion 206S by a tubular extension member 222. The tubular extension member 222 extends from the inner end of the smaller diameter portion 206F into the larger diameter portion 206S of the through-passage 206. One or more ties 224 may extend from the outer wall of the tubular member 222 to the inner wall of the second end region 202S of the elongate plastics sleeve 202. The free end surface 228 of the tubular member 222 defines a seat against which the nail head 66 of the masonry nail 64 presses when the cavity wall tie is installed. The provision of the one or more ties 224 strengthens the tubular member 222 to allow it to absorb the impact of the nail head 66 when fired from the nail gun and provide a stable seat for the nail head. The one or ties 224 may comprise one or more radially extending spokes extending outwardly from the tubular member 222.

[0022] In similar fashion to the sleeve fitting 20, the sleeve fitting 200 may be provided with a slot 233 through which the elongate tie member extends to pass through the flange 204. The slot may be configured to enable the elongate tie member to deflect, or flex, away from a nail gun when the cavity wall tie is loaded onto the nosepiece of the nail gun.

[0023] Figure 9 shows an elongate tie member 312 and sleeve holder 314 attached to the elongate tie member that may be used with sleeve fittings the same as, or similar to, the sleeve fitting 200 shown in Figures 6 to 8. Although not essential, the elongate tie member 312 and the sleeve holder 314 may be formed as an integral plastics moulding.

[0024] The elongate tie member 312 may comprise a rectangular section member that extends rearwardly from a rearward edge 313 of the sleeve holder 314. The sleeve holder 314 may be configured to receive at least the leading end part of the first end region 202F of the plastics sleeve 202. In particular, the sleeve holder 314 may comprise an at least partially tapered opening 315 that extends axially forwardly from the rear edge 313 and is shaped to cooperably engage at least the leading end part of the first end region 202F. In some examples, the at least partially tapered opening 315 may be configured to at least substantially conform to the shape of the leading end part of the first end region 202F. At the forward edge, or leading end, 317 of the sleeve holder 314, the nail holder may comprise a relatively narrow forward end opening 319 that is aligned with the at least partially tapered opening 315 so that there is a continuous through-passage defined within the sleeve holder. The forward end opening 319 may have a diameter that is not greater than the diameter of the tip of the leading end part of the first end region 202F of the plastics sleeve 202 so that the first end region cannot enter the forward end opening 319. The forward end opening 319 may have a diameter a little greater than the diameter of the nails the cavity wall tie is intended to be used with. Thus, unlike the example shown in Figure 1, the plastics sleeve 202 does not extend through the sleeve holder 314, although, this is not essential and the sleeve holder may be configured so that there is some projection of the plastics sleeve beyond the forward edge 317.

[0025] The elongate tie member 312 may comprise a series of holes 321 disposed at spaced apart intervals along the longitudinal axis 323 of the elongate tie member over at least a part of the length of the elongate tie member. The holes 321 may be through holes or blind holes that extend inwardly from one or both of the major surfaces of the elongate tie member. The holes 321 receive mortar when the wall is formed to improve keying of the mortar with the elongate tie member 312 and reduces the amount of material needed to form the elongate tie member.

[0026] The elongate tie member 312 may be marked with a series of cut lines 323. In examples in which the elongate tie member 312 is provided with holes 321, the cut lines 323 may be disposed intermediate the holes. Although not essential, the holes 321 may be disposed in equidistant spaced apart relationship and the cut lines 323 may be disposed centrally between adjacent holes. The cut lines 323 may be configured to indicate places at which the elongate tie member 312 may be cut to provide an elongate tie member that can be configured to a selected predetermined length within a range of predetermined lengths. In some examples, the cut lines 323 may be defined by notches formed in a major surface of the elongate member312 that extend widthways from a first side 325 of the elongate tie member to the second, opposite, side 327. There may be cut lines 323 in the form of notches in just one of the major surfaces or in both. Where the cut lines 323 comprise notches, they may have a V-shaped cross-section.

[0027] Cut lines 323 formed as notches may act as weakening points that allow an unwanted length of elongate tie member 312 to be broken off from the remainder of the tie member without the aid of a cutting tool.

[0028] In some examples, the elongate tie member 312 may be curved in the widthways direction so that the major surface that is on the side of the tapered opening 315 is dished and defines a channel extending in a lengthways diameter of the elongate tie member.

[0029] In the illustrated examples, the at least one resilient gripper comprises a plurality of triangular projections. It is to be understood that this is not essential. In principle the at least one resilient gripper may comprise a part that has a base attached to the flange and an end that overlies the longitudinally extending cavity so that when the sleeve fitting is pushed onto the nosepiece of a nail gun the at least one resilient gripper is deflected away from the centre of the through-hole by the nosepiece to centre the sleeve fitting on the nosepiece and retain the cavity wall tie on the nosepiece while it is offered up to the surface of a cavity wall against which it is to be secured by a nail fired from the nail gun. The longitudinally extending cavity may be tapered over at least a part of its length or be provided with an internally disposed step to limit insertion of the nosepiece and provide a resistance that pushes the nosepiece back to its firing position when the cavity wall tie is pressed against a substrate.

[0030] In the illustrated example, the nail holder comprises a sleeve fitting that is attached to the elongate tie member by a sleeve holder. This is not essential. A sleeve fitting with a relatively large flange may be advantageous when fitting the cavity wall tie to a relatively softer substrate abutting the inner leaf of the cavity wall, for example a layer of thermal insulation. However, in principle, the sleeve fitting may be omitted, particularly if it is intended that that the cavity wall tie is to be secured directly to the inner leaf of the cavity wall. In examples intended for this usage, the nail holder may be a metallic component attached to or integral with the elongate tie member that defines a sleeve with a seat for the head of the nail and is configured to receive the leading end of a nosepiece of a nail gun. Alternatively, the nail holder may comprise a laterally extending member or members that define a seat for a nail head and are provided with a series of projections defining a longitudinally extending cavity to receive the nosepiece of the nail gun.

[0031] It is to be understood that while typically the cavity wall tie will be secured to the inner leaf of a cavity wall by a masonry nail fired into mortar of the inner leaf, this is not essential. In some installations, the cavity wall tie may be secured to timber framing and so it is not essential the nail is a masonry nail.

[0032] The elongate tie member may be a metallic component and when the nail holder comprises a sleeve fitting, the sleeve holder is a metallic component. In examples in which there is no sleeve fitting, the nail holder is typically a metallic component. However, embodiments are envisaged in which the nail holder comprises a simple plastics cup-like component attached to the elongate tie member similar to the sleeve holder shown in Figures 9 and 10 that is configured to receive the leading end of the nosepiece of a nail gun and define a seat for the head of a masonry nail when the cavity wall tie is installed.

[0033] In the examples illustrated by Figures 1 to 8, the elongate tie member and sleeve holder are made of a suitable metal, typically a steel, and the sleeve fitting is made of a suitable plastics material. However, in other examples, such as those illustrated by Figures 6 to 10, the elongate tie member, nail holder and sleeve fitting may all be made of a plastics material.

[0034] It is to be understood that it is not essential that the courses of the cavity wall are bonded to one another using mortar. Any suitable bonding material known to the skilled person, for example cement, may be used.

Claims

1. A cavity wall tie comprising an elongate tie member (12; 312) to bridge a cavity in a cavity wall and a nail holder attached to said elongate tie member, wherein said nail holder defines a passage (16, 24; 206F, 206S, 212; 315, 319) through which, in use, a nail is driven by a nail gun to secure said elongate tie member to a leaf of a cavity wall, and wherein said nail holder comprises a longitudinally extending cavity (24; 206F, 206S) that at least partially defines said passage, and wherein said longitudinally extending cavity is configured to receive a leading end of a nosepiece of said nail gun and is provided with an internally disposed seat (228) for a head of said nail that is engaged by said head when said nail is securing said elongate tie member to said leaf of a cavity wall.

2. A cavity wall tie as claimed in claim 1, wherein said nail holder comprises a sleeve fitting (20; 200) comprising an elongate plastics sleeve (22; 202) that defines said longitudinally extending cavity (24; 206F, 206S) and said seat (228).

3. A cavity wall tie as claimed in claim 2, wherein said elongate tie member (12; 312) is attached to a first end region of said sleeve fitting (20; 200), a flange (26; 204) is disposed at a second end region of said sleeve fitting and a second end region (31) of said elongate tie member (12) extends through said flange (26) and defines a free end of said elongate tie member.

4. A cavity wall tie as claimed in claim 3, wherein said nail holder comprises a sleeve holder (14; 314) that extends laterally of said elongate tie member (12; 312) and said first end region of said elongate plastics sleeve (22; 202) is received in an opening (16; 315, 319) defined by said sleeve holder.

5. A cavity wall tie as claimed in claim 3 or 4, wherein said flange (26; 204) is provided with at least one resilient gripper (36; 214) that at least partially overlies said longitudinally extending cavity (24; 206F, 206S).

6. A cavity wall tie as claimed in claim 5, wherein said at least one resilient gripper comprises a plurality of spaced apart projections (36; 214) that project from said flange (26; 204).

7. A cavity wall tie as claimed in claim 5 or 6, wherein said at least one resilient gripper comprises a triangular projection (36; 214) having a base joined to said flange (26; 204) and an apex that lies over said longitudinally extending cavity (24; 206F, 206S).

8. A cavity wall tie as claimed in any one of claims 2 to 7, wherein said elongate tie member (12; 312) extends alongside said elongate plastics sleeve (22; 202) spaced apart from said elongate plastics sleeve.

9. A cavity wall tie as claimed in any one of the preceding claims, wherein said elongate tie member (312) is a plastics member provided with a plurality of cut lines (323) that extend in a widthways direction of said elongate tie member to provide an elongate tie member that can be configured to a plurality of predetermined lengths within a series of predetermined lengths.

10. A cavity wall tie system comprising a cavity wall tie as claimed in any one of the preceding claims and a nail (64).

11. A cavity wall comprising an inner leaf (52), an outer leaf (54) and a cavity wall tie system as claimed in claim 10, wherein said nail (64) extends through said nail holder and is embedded in said inner leaf to secure said elongate tie member to said inner leaf and a free end of said elongate tie member overlies a part of said outer leaf.

12. A method of installing a cavity wall tie to a cavity wall, wherein said cavity wall tie comprises an elongate tie member and a nail holder attached to said elongate tie member and said method comprises: locating a nosepiece of a nail gun in a longitudinally extending cavity of said nail holder; and securing an elongate tie member of said cavity wall tie that is attached to said nail holder to a first leaf of said cavity wall by a nail fired from said nail gun that passes through said longitudinally extending cavity such that a head of said nail engages a seat defined within said longitudinally extending cavity, said nail securing said elongate tie member to said first leaf such that a free end of said elongate tie member is disposed over a course of a second leaf of said cavity wall.

13. A method as claimed in claim 12, further comprising embedding said free end in a bonding material applied to said course of said second leaf.

14. A method as claimed in claim 13, wherein said bonding material comprises cement or mortar.

15. A method as claimed in claim 12, 13 or 14, wherein: said nail holder comprises a sleeve fitting that defines said longitudinally extending cavity and said seat and said elongate tie member is connected with a first end region of said sleeve fitting; and locating said cavity wall tie on said nosepiece comprises inserting said nosepiece into said longitudinally extending cavity at a second end region of said sleeve fitting.

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