US20090056263A1

US20090056263A1 - Cavity wall spacer, building structure and method

Info

Publication number: US20090056263A1
Application number: US12/229,009
Authority: US
Inventors: Charlie Ayers
Original assignee: Surecav Ltd
Current assignee: Surecav Ltd
Priority date: 2007-08-20
Filing date: 2008-08-18
Publication date: 2009-03-05
Also published as: CA2639142C; EP2028326A1; EP2028326B1; CA2639142A1

Abstract

A cavity wall spacer, building structure, and method are disclosed. The cavity wall spacer determines a separation of building elements of two leaves of a wall. The cavity wall spacer comprises: a support body; and a plurality of spaced projections upstanding from the support body and operable to extend across a cavity between the leaves, each projection having a recessed channel operable to inhibit transfer of moisture from one end of each projection to another. The recessed channel prevents the passage of moisture along the length of the projection to prevent moisture from traveling between the two leaves of the wall, and reduces the amount of moisture which drips into the cavity. The recessed channel has no external obstructions and thus allows significantly improved stacking density. The projections are less prone to any damage since there are no external protrusions.

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to European Patent Application No. 07253268.2 entitled Cavity Wall Spacer, Building Structure, and Method, filed Aug. 20, 2007.

BACKGROUND OF THE INVENTION

1. Field of the Invention
The present invention relates to a cavity wall spacer, a building structure and method.
2. Related Art
Many modern buildings for habitation are now constructed using cavity walls. Cavity walls are generally more effective for improving thermal insulation and inhibiting of moisture penetration compared to solid walls. Cavity walls consist of two walls or “leaves” of masonry separated by a cavity or gap. Typically, the walls are 100 mm thick, separated by a 50 mm gap. The walls may be constructed from bricks, concrete blocks, hollow clay bricks, timber framing, natural stone, or a combination of these materials. The exterior wall or leaf is usually constructed from bricks. The exterior leaf and the interior leaf are tied together at spaced intervals with wall ties spanning the cavity.
Disclosed herein is an improved cavity wall spacer.

SUMMARY OF THE INVENTION

According to a first aspect of the present invention there is provided a cavity wall spacer for determining a separation of building elements of two leaves of a wall during construction, the cavity wall spacer comprising: a support body; and a plurality of spaced projections upstanding from the support body and operable to extend across a cavity between the two leaves, each projection having a recessed channel operable to inhibit transfer of moisture from one end of each projection to another.
The first aspect recognizes that a problem with the existing cavity wall spacers is that they either have no moisture barrier rib, in which case more moisture than may be desirable can track along the length of the projection from the external leaf to the internal leaf, or they have a moisture barrier rib and this causes moisture to gather and then drip into the cavity in the vicinity of the moisture barrier rib. Also, a problem with arrangements having moisture barrier ribs is that when the sheets of cavity wall spacers are stacked for storage or transport the packing density of the sheets is low since the barrier rib prevents close stacking of the sheets. Furthermore, these barrier ribs can become damaged.
Accordingly, the first aspect provides at least one projection, and more typically a plurality of projections, each having a recessed channel. The recessed channel or groove helps to prevent the passage of moisture along the length of the projection which provides an efficient way of preventing moisture traveling between the two leaves of the wall. Also, a recessed channel reduces the amount of moisture which drips into the cavity since the moisture is more likely to track back along the surface of the projection. Additionally, providing a recessed channel ensures no external obstruction on the projections which helps to achieve a significantly improved stacking density. Furthermore, the projections are less prone to any damage since there are no external protrusions.
In one embodiment, the recessed channel is operable to cause moisture flowing from one end of the projection to another to collect therein. Accordingly, the recessed channel provides a depression or gully into which any moisture traveling along the length of the projection may accumulate.
In one embodiment, the recessed channel is operable to cause the moisture collected therein to gather at a moisture-release point. Hence, the channel acts as a conduit along which the accumulated moisture may flow to a moisture-release point. It will be appreciated that in practice small droplets will accumulate in the recessed channel which will combine into larger droplets which, once a sufficient mass has been achieved, will overcome surface tension and will flow along the recessed channel under gravity to the underside of the recessed channel when installed in the cavity. The underside of the channel when installed in the cavity may provide two moisture-release points, one at each side of the recessed channel.
In one embodiment, each projection is tapered towards its distal end and the recessed channel is operable to direct moisture gathered at the moisture-release point towards that projection's proximal end. Hence, in a tapered arrangement, any moisture gathered at the moisture-release point (which is typically on the underside of the projection when installed in the cavity) will be likely to travel under gravity back along the outer surface of the projection back towards the support body rather than drip into the cavity itself.
In one embodiment, the recessed channel is located between proximal and distal ends of the projection.
In one embodiment, the recessed channel is located towards the distal end of the projection.
In one embodiment, the recessed channel is located in a distal face of the projection. Hence, rather than be located along the length of the projection, the recessed channel may be formed in the tip of the projection.
In one embodiment, the recessed channel extends at least partly circumferentially about the projection.
In one embodiment, the recessed channel extends entirely circumferentially about the projection.
In one embodiment, each projection has two converging lateral walls.
In one embodiment, each projection has a lenticular cross-section.
In one embodiment, each projection is hollow. It will be appreciated that providing a hollow projection increases the stacking density.
In one embodiment, the support body and the projections are integrally formed.
In one embodiment, each projection extends transversely of the support body.
In one embodiment, each projection extends from a face of the support body.
According to a second aspect of the present invention there is provided a building structure incorporating one or more cavity wall spacers according to the first aspect in a cavity wall of the building structure.
In one embodiment, the cavity wall spacers are located at spaced intervals in the cavity wall of the building structure
According to a third aspect of the present invention there is provided a method of erecting a building having a cavity wall of two or more leaves comprising the steps of: erecting part of one leaf of the cavity wall of the building; securing to the erected part of the one leaf of the cavity wall a cavity wall spacer according to the first aspect, and erecting at least part of another leaf of the cavity wall of the building in a position spaced from the one leaf by a distance determined by the cavity wall spacer.
In one embodiment, the spacer device is orientated in the cavity wall of the building so that the support body of the cavity wall spacer is against an inner face of an exterior leaf of the cavity wall and the plurality of projections of the support body extends toward an interior leaf of the cavity wall of the building.
In one embodiment, the cavity wall spacer is orientated so that distal ends of the plurality of projections abut an inner face of the interior leaf of the cavity wall of the building.
Other systems, methods, features and advantages of the invention will be or will become apparent to one with skill in the art upon examination of the following figures and detailed description. It is intended that all such additional systems, methods, features and advantages be included within this description, be within the scope of the invention, and be protected by the accompanying claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The components in the figures are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention. In the figures, like reference numerals designate corresponding parts throughout the different views.

FIG. 1 is a perspective view of a cavity wall spacer according to one embodiment;

FIG. 2 is a side view of the cavity wall spacer of FIG. 1;

FIG. 3 is a sectional view of a cavity wall of a building incorporating the spacer device of FIG. 1;

FIG. 4 is a sectional view showing the stacking arrangement of a number of sheets of spacer devices of FIG. 1;

FIG. 5 is a perspective view of a sheet cavity wall spacers of FIG. 1;

FIG. 6 is a perspective view of a cavity wall spacer of a further embodiment;

FIG. 7 shows further views of the cavity wall spacer of FIG. 6; and

FIG. 8 is a perspective view of a sheet of cavity wall spacers of FIG. 6.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the following description, numerous specific details are set forth in order to provide a more thorough description of the present invention. It will be apparent, however, to one skilled in the art, that the present invention may be practiced without these specific details. In other instances, well-known features have not been described in detail so as not to obscure the invention.
For a cavity wall to effectively work as a moisture barrier, the cavity or gap should not be bridged in any way. A cavity wall spacer may be used to inhibit the transfer of moisture from the exterior leaf to the interior leaf in one or more embodiments. GB 2 388 614, which is incorporated herein by reference, illustrates an example of a spacer that may be used in this manner. The cavity wall spacer disclosed herein, comprises a novel configuration which provides various advantages which will be apparent from the description below.
Referring to FIG. 1, there is shown a cavity wall spacer, generally 11, according to one embodiment. The cavity wall spacer 11 is integrally formed by vacuum molding and has a support body 12 with a plurality of projections 13 extending transversely from the plane of the support body 12. Although FIG. 1 shows just one projection 13, this is just one portion of the support body 12 which is a laminar sheet having overall dimensions of 1200 mm by 450 mm and a depth of 50 mm with a plurality of these projections 13 extending therefrom as shown in more detail in FIG. 5. The support body 12 and the projections 13 of the spacer device 11 are made from a plastics material which is high-density polyethylene (HDPE) having a thickness of around 2 mm. The plurality of projections 13 are longitudinal and have a proximal end 14 located adjacent to an inner face of the support body 12 and a distal end 15 located away from the support body 12. Each of the projections 13 are spaced away from each other typically by a distance of 260 mm between centers horizontally and 125 mm between centers vertically. The projections 13 have a lenticular shape. A recessed channel or groove is formed as an indentation or depression in the surface of the projection 13. In this arrangement, the recessed channel 16 extends entirely circumferentially about the projection 13. The spacer device 11 is primarily for use in a cavity wall of a building structure to prevent or at least inhibit water or moisture from penetrating the building.
Referring to FIG. 2, there is shown a sectional view of the spacer device 11 having the support body 12 and the plurality of projections 13. The recessed channel 16 spaced towards the distal face 15 of the projection 13.
Referring to FIG. 3, the cavity wall spacer 11 is incorporated in a cavity 17 of a cavity wall 18 of a building structure (again, just a portion of the complete sheet is shown). The cavity wall 18 has an exterior wall 19 and an interior wall 20 and may optionally include a layer 21 of an insulating material on an inner face of the interior wall 20. Alternatively, the insulation layer 21 may be separate from the cavity wall spacer 11, and the cavity wall spacer 11 may retain the separate insulation layer 21 in place against the inner face of the interior wall 20. The exterior and interior walls 19, 20 are constructed from bricks, although they may also be constructed from concrete blocks, hollow clay bricks, timber framing or natural stone. The spacer device 11 is located in the cavity 17 of the cavity wall 18.
The support body 12 of the spacer 11 lies against an inner face of the exterior wall 19 with the plurality of projections 13 extending toward the inner face of the interior wall 20. The recessed channels 16 are located towards the distal end of the projection 13 in the region near the inner face of the interior wall and function as a “water bar” to prevent or hinder the penetration of water or moisture into the interior wall 20 of the building. Any water which enters the cavity 17 flows along the outer surface of the projections 13 to the recessed channel 16 whereupon further water penetration into the cavity 17 is prevented. The recessed channel 16 causes water droplets to form and, when a sufficiently sized droplet has formed, it is guided within the conduit formed by the recessed channel around the exterior of the projection 13 to two moisture-release points 17 a, 17 b which are located on either side of the recessed channel 16 at the lower intersection of the two arcs forming the lenticular cross-section of the projection 13. From here, the water droplet will either drip downwardly from the projections 13 to the ground surface where weep holes (not shown) may be provided in the exterior wall to drain the water from the cavity 17. Alternatively, the water droplet will track back along the external surface of the projection 13 towards the exterior wall 19. Eventually, the water droplet will then gather on the ground surface in the vicinity of the weep holes in the exterior wall 19.
The projections 13 have a lenticular shape having upper and lower ridges defined by the region where the converging arcs intersect. The side walls of the projections are steeply angled relative to the axis of the projection 13 which causes the water droplets to travel down the walls to the lower ridge.
As shown in FIG. 5, the laminar support body 12 will typically have dimensions of 1200 mm by 450 mm and the projections 13 are spaced across a face of the support body 12 and formed into three rows and five columns.
A plurality of the spacer devices is typically installed in a cavity wall of a building in a plurality of rows and columns. Typically, wall ties (not shown) are located in the cavity 17 at regular spaced intervals. The substantially horizontal spacing between adjacent wall ties is usually about 900 mm and the substantially vertical spacing between adjacent wall ties is usually about 450 mm. These measurements correspond approximately to the dimensions of the spacer device so that it may be positioned in a cavity wall between spaced wall ties.
Each spacer device may be connected to another spacer device in the cavity wall using H-shaped connection elements (not shown) having two longitudinal parallel walls joined together at a middle region thereof by an integral longitudinal member so as to define U-shaped channels, each of which can receive a part of the support body of adjacent spacer devices. In this way, one spacer device can be connected to another spacer device to create a sufficiently stable structure of spacer devices in the cavity wall.
Referring now to FIG. 4, there is shown a plurality of spacer devices stacked upon each other. As can be seen, a high packing density can be achieved since the absence of any external protrusions enables the spacer devices to readily slide over each other and stack in close formation.
Referring to FIG. 6, there is illustrated a spacer device, generally 11′ according to a further embodiment. Once again, the spacer device 11′ is integrally formed by vacuum molding and has a support body 12′ with a plurality of projections 13′ extending transversely from the plane of the support body 12′. The support body 12′ is a laminar sheet. The support body 12′ and the projections 13′ of the spacer device 11′ are made from a plastics material. The plurality of projections 13′ are longitudinal and have a proximal end 14′ located adjacent to the support body 12′ and a distal end 15′ spaced away from the support body. The projections 13′ have a generally lenticular shape.
A recessed channel 16′ is formed in the distal end 15′. The recessed channel 16′ extends entirely circumferentially around distal end 15′. The recessed channel 16′ functions in a similar way to the arrangement shown in FIGS. 1 to 3 and acts to divert moisture within the cavity 17 away from the inner wall 20.
As shown in FIG. 8, the laminar support body 12′ will typically have dimensions of 1200 mm by 450 mm and the projections 13′ are spaced across a face of the support body 12′ and formed into three rows and five columns.
Hence, it can be seen that the cavity wall spacers 11, 11′ both inhibit the transfer of moisture from the external wall to the internal wall. Also, the recessed channel 16, 16′ reduces the amount of moisture which drips into the cavity since the moisture is more likely to track back along the surface of the projection. Additionally, a high staking density of the cavity wall spacers 11, 11′ can be achieved since there are no external protrusions which would otherwise prevent the exterior of the spacer device 13, 13′ from closely mating with the interior of a further cavity wall spacer stacked thereon. Furthermore, by avoiding any external protrusions the risk of damage to the cavity wall spacers 11, 11′ is reduced.
While various embodiments of the invention have been described, it will be apparent to those of ordinary skill in the art that many more embodiments and implementations are possible within the scope of this invention. In addition, the various features, elements, and embodiments described herein may be claimed or combined in any combination or arrangement.

Claims

1. A cavity wall spacer for determining a separation of building elements of two leaves of a wall during construction, said cavity wall spacer comprising:

a support body; and

a plurality of spaced projections upstanding from said support body and operable to extend across a cavity between said two leaves, each projection having a recessed channel operable to inhibit transfer of moisture from one end of each projection to another.

2. The cavity wall spacer of claim 1, wherein said recessed channel is operable to cause moisture flowing from one end of said projection to another to collect therein.

3. The cavity wall spacer of claim 2, wherein said recessed channel is operable to cause said moisture collected therein to gather at a moisture-release point.

4. The cavity wall spacer of claim 3, wherein each projection is tapered towards its distal end and said recessed channel is operable to direct moisture gathered at said moisture-release point towards that projection's proximal end.

5. The cavity wall spacer of claim 1, wherein said recessed channel is located between proximal and distal ends of said projection.

6. The cavity wall spacer of claim 5, wherein said recessed channel is located towards said distal end of said projection.

7. The cavity wall spacer of claim 1, wherein said recessed channel is located in a distal face of said projection.

8. The cavity wall spacer of claim 1, wherein said recessed channel extends at least partly circumferentially about said projection.

9. The cavity wall spacer of claim 1, wherein said recessed channel extends entirely circumferentially about said projection.

10. The cavity wall spacer of claim 1, wherein each projection has two converging lateral walls.

11. The cavity wall spacer of claim 1, wherein each projection has a lenticular cross-section.

12. The cavity wall spacer of claim 1, wherein each projection is hollow.

13. The cavity wall spacer of claim 1, wherein said support body and said projections are integrally formed.

14. The cavity wall spacer of claim 1, wherein each projection extends transversely of said support body.

15. The cavity wall spacer of claim 1, wherein each projection extends from a face of said support body.

16. The cavity wall spacer of claim 1 further comprising a building structure having a cavity wall, wherein one or more cavity wall spacers are incorporated in said cavity wall of said building structure.

17. The cavity wall spacer of claim 16, wherein said one or more cavity wall spacers are located at spaced intervals in said cavity wall of said building structure.

18. A method of erecting a building having a cavity wall of two or more leaves comprising the steps of:

erecting part of one leaf of said cavity wall of said building;

securing to said erected part of said one leaf of said cavity wall a cavity wall spacer, said cavity wall spacer comprising a support body and a plurality of projections; and

erecting at least part of another leaf of said cavity wall of said building in a position spaced from said one leaf by a distance determined by said cavity wall spacer.

19. The method of claim 18, wherein said cavity wall spacer is orientated in said cavity wall of said building so that said support body of said cavity wall spacer is against an inner face of an exterior leaf of said cavity wall and said plurality of projections of said support body extend toward an interior leaf of said cavity wall of said building.

20. The method of claim 19, wherein said cavity wall spacer is orientated so that distal ends of said plurality of projections abut an inner face of said interior leaf of said cavity wall of said building.