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(11) | EP 0 168 199 A2 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | A method of building a cavity wall using a building tie, and building ties for use in the method |
| (57) A method of building a cavity wall including the step of embedding in the leaves
of the cavity wall a tie to locate them in position characterised in that a tie is
used in which at least the portions which are located in the walls and adjacent to
the leaves of the wall are of spiral form and obtained by twisting a flat strip of
metal. |
[0001] This invention relates to a method of building a cavity wall and to ties which may be used in the method of the invention.
[0002] According to the present invention a method of building a cavity wall includes the step of embedding in the leaves of the cavity wall a tie to locate them in position the method being characterised in that a tie is used in which at least the portions which are located in the walls and adjacent to the leaves of the wall are of spiral form and obtained by twisting a flat strip of material, preferably of metal.
[0004] The invention also relates to a building tie for use in the method as set forth which is formed by twisting a flat strip of metal at least at its ends into a spiral and preferably over the whole of its length.
[0005] The tie is preferably of a width of approximately 7 millimetres, with a thickness of I millimetre. Conveniently the pitch of the turns of the spiral are between 15 and 20 mm and although the tie may be of any suitable length it is conveniently of 200 - 205 mm.
[0007] The invention may be performed in various ways and one specific embodiment will now be described by way of example with reference to the accompanying drawings in which:
Figure 1 is a perspective view of a wall tie.
Figure 2 is a section on the line 2-2 of figure 1 and
Figure 3 is a tie embedded into the two leaves of a cavity wall.
[0008] The wall tie shown is formed from a flat strip of metal by twisting it so as to obtain the spiral form shown. The most suitable material for the strip has been found to be 304 stainless steel or 316 stainless steel.
[0009] In one prefered construction the width of the stainless steel strip used is 7 mm, its thickness lmm, and has pitch of 15 - 20 mm between adjacent turns of the spiral. In most constructions the length is of 200 - 205 mm, although it can be of any convenient length.
[0010] In the method of building the cavity wall of invention the building ties are embedded in the wall as shown in Figure 3. Each end of the tie indicated generally at 1 is embedded into a layer of mortar 2 between bricks or other building blocks 3 forming the leaves of the wall.
[0011] By having the tie of spiral form at its ends a particularly good grip can be obtained in the two leaves which are to be tied together. These are in fact normally cavity walls in new houses. Moreover one of the difficulties with existing building ties has been that condensation of water tends to flow towards one or other wall and does not readily leave the tie. Although by having a twist adjacent to each wall the problem is mainly solved, it is preferable to have the tie of spiral form throughout and in this case the water cannot readily flow along the tie and thus leaves it away from the structures to be supported.
1. A method of building a cavity wall including the step of embedding in the leaves
of the cavity wall a tie to locate them in position characterised in that a tie is
used in which at least the portions which are located in the walls and adjacent to
the leaves of the wall are of spiral form and obtained by twisting a flat strip of
metal.
2. A method as claimed in claim 1 characterised in that a tie is used which is of
spiral form throughout its length.
3. A building tie for use in the method as claimed in claim I or claim 2 which is
formed by twisting a flat strip of metal into a spiral.
4. A building tie as claimed in claim 3 characterised in that it has a width of 7mm,
and a thickness of lmm.
5. A building tie as claimed in claim 4 characterised in that the pitch of the turns
of the spiral are between 15 and 2v mm.
6. A building tie as claimed in claim 4 or claim 5 characterised in that the length
of the tie is between 200 and 205 mm.
7. A cavity wall including a building tie as claimed in any one of claims 3 to 6.