NZ732496A - A firestopping device and associated method - Google Patents

Abstract

embodiment of the firestopping device 1 includes a body 2 having a first opening 3 at a first end 5, a second opening 4 at a second end 6 and an internal volume intermediate the first and second ends 5 and 6. The internal volume and each of the openings is sized such that at least one service may extend through the firestopping device 1. An intumescent material 7 is housed within the internal volume, the intumescent material being responsive to heat so as to swell within the internal volume. At least one attachment formation 10 is disposed at or adjacent to the first opening, the attachment formation 10 being configured for attachment of the firestopping device 1 to an external surface 19. extend through the firestopping device 1. An intumescent material 7 is housed within the internal volume, the intumescent material being responsive to heat so as to swell within the internal volume. At least one attachment formation 10 is disposed at or adjacent to the first opening, the attachment formation 10 being configured for attachment of the firestopping device 1 to an external surface 19.

Description

A FIRESTOPPING DEVICE AND ASSOCIATED METHOD TECHNICAL FIELD The present invention relates to the field of passive fire protection. Embodiments of the present invention find application, though not exclusively, in the construction of buildings such as residential apartment buildings and the like.

BACKGROUND ART Any discussion of documents, acts, materials, devices, articles or the like which has been included in this specification is solely for the purpose of providing a context for the present invention. It is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present invention as it existed in Australia or elsewhere before the priority date of this application.

In a typical prior art method for constructing a residential apartment building the floors and walls are constructed prior to installation of the services such as electrical cables, water pipes, etc. In this prior art method, a hole is made in the floor or wall for each of the services, which typically must be separated by a standard separation distance, such as 200 mm for example. This separation distance requires significantly larger overall areas for services, which severely limits the design options for construction. Each of the individual holes through which the services extend must then be separately sealed in a fire rated fashion, which can be time consuming and expensive.

SUMMARY OF THE INVENTION It is an object of the present invention to overcome, or substantially ameliorate, one or more of the disadvantages of the prior art, or to provide a useful alternative.

In one aspect of the present invention there is provided a firestopping device including: a body having a first opening at a first end, a second opening at a second end and an internal volume intermediate the first and second ends, the internal volume and each of the openings being sized such that at least one service may extend through the firestopping device; an intumescent material being housed within the internal volume, the intumescent material being responsive to heat so as to swell within the internal volume; and at least one attachment formation being disposed at or adjacent to the first opening, the attachment formation being configured for attachment of the firestopping device to an external surface.

In an embodiment the attachment formation is an outwardly extending flange disposed at the first opening. Preferably the outwardly extending flange includes a plurality of holes each being sized so as to receive a fastener extending there through. Also preferably the outwardly extending flange is substantially orthogonal to the body.

In an embodiment an external surface of the body includes keying formations such that when at least part of the body is encased within a settable material, the body keys into the settable material upon hardening of the settable material. Preferably the body defines an elongate dimension and the keying resists movement of the body relative to the hardened settable material in the direction of the elongate dimension. Also preferably the keying formation is a plurality of projections having a component of projection that is orthogonal to the body. In an embodiment the plurality of projections are a plurality of fasteners, which are preferably rivets that are used to connect planar panels so as to form the body.

According to a second aspect of the invention there is provided a method of constructing a barrier having a fire rated passageway extending there through, the method including the steps of: providing a firestopping device including a body having a first opening at a first end, a second opening at a second end and an internal volume intermediate the first and second ends, the internal volume and each of the openings being sized such that at least one service may extend through the firestopping device, an intumescent material being housed within the internal volume, the intumescent material being responsive to heat so as to swell within the internal volume; positioning the firestopping device within a space into which a settable material is to be poured; and pouring the settable material into the space such that at least a proportion of the body is encased within the settable material and such that the first and second openings are disposed on either side of the settable material such that the internal volume defines the fire rated passageway.

In an embodiment of the method, at least one attachment formation is disposed at or adjacent to the first opening, the attachment formation being configured for attachment of the firestopping device to an external surface. In this embodiment of the method the space is at least partly defined by an external surface and “positioning the firestopping device within a space into which a settable material is to be poured” includes affixing the attachment formation to the external surface.

Preferably an external surface of the body includes keying formations and, once the at least a proportion of the body has been encased within the settable material and the settable material has hardened, the body is keyed into the hardened settable material. Also preferably the keying resists movement of the body relative to the hardened settable material in the direction of the elongate dimension.

According to another aspect of the invention there is provided a barrier constructed in accordance with the method described above.

The features and advantages of the present invention will become further apparent from the following detailed description of preferred embodiments, provided by way of example only, together with the accompanying drawings.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS Figure 1 is an upper perspective view of an embodiment of a firestopping device; Figure 2 is a lower perspective view of the embodiment; Figure 3 is a plan view of the embodiment; Figure 4 is a side view of the embodiment; Figure 5 is a cross sectional view of the embodiment as viewed through line B-B of figure 4; Figure 6 is a front view of the embodiment; Figure 7 is a cross sectional view of the embodiment as viewed through line C-C of figure 6; Figure 8 is an upper perspective view of the embodiment including upper and lower foam inserts; Figure 9 is an upper perspective view of the embodiment with the foam inserts seated within; Figure 10 is an upper perspective view of the embodiment prior to the laying of a concrete slab; and Figure 11 is an upper perspective view of a portion of the embodiment that protrudes after laying of the slab.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION The illustrated embodiment of the firestopping device 1 includes a body 2 having a first opening 3 at a first end 5 and a second opening 4 at a second end 6, which is opposite to the first end. If the firestopping device 1 is proposed to be used in a flooring context, then the first end 5 is the base and the second end is the top and the body 2 typically extends vertically.

If the firestopping device 1 is proposed to be incorporated into a wall, then the unit is rotated through 90º such that the first and second ends form the sides of the unit and the body 2 extends horizontally.

The body 2 defines an internal volume intermediate the first and second ends 5 and 6. The sizing of the internal volume and each of the openings 3 and 4 is selected to ensure that at least one service, and preferably a plurality of services, may extend through the firestopping device 1 once it is in use.

Four pieces of intumescent material 7 are housed within the internal volume of the firestopping device 1. More specifically, one piece of intumescent material 7 is disposed against each of the side walls 8. Each piece of intumescent material 7 is retained in position by a pair of flanges 9, which allows for easy initial installation and subsequent replacement of the intumescent material 7 for long term maintenance purposes.

In the event of exposure to the heat of a fire, the intumescent material 7 responds by swelling within the internal volume of the firestopping device 1. This resists the passageway of fire and smoke through the firestopping device 1.

Another embodiment makes use of differing specifications of intumescent materials to provide a two-stage expansion process, which has the potential to improve the performance of the firestopping device 1.

In the illustrated embodiment the firestopping device 1 (with the exception of the intumescent material 7) is made from a metallic material such as mild steel, or 1.1 mm Zincanneal steel sheeting, which is folded on brake presses and turret punched to form the panels that make up the body 2. However, in another embodiment all or part of the external casing of the firestopping device 1 is made from a thermally insulative material, such as calcium silicate for example, to resist the thermal conduction of heat across the firestopping device 1.

If the preferred embodiment is proposed to be used within a particularly thick concrete slab, then it is advisable to utilise a stronger material to withstand the crushing force that may be exerted by the concrete prior to its hardening. This may be achieved with the use of thicker sheet metal material, such as 2.0 mm Zincanneal steel sheeting, for example. An additional or alternative option is to include bracing, which extends across the internal volume to help the device 1 to resist the forces exerted by the concrete.

An attachment formation, in the form of an outwardly extending flange 10, is disposed at the first opening 3. This flange 10 is orthogonal to the body 2 and includes a plurality of holes 11 that are regularly spaced along the flange 10. Each of the holes 11 is sized so as to receive a fastener extending there through. In use, fasteners, such as nails, screws or the like, are driven through the holes 11 and into an external surface, which is typically wooden formwork, so as to attach the firestopping device 1 to the desired position upon the formwork prior to pouring of the cement slab.

The external surface of the body 2 includes keying formations such that when the body 2, or at least a sufficient part thereof, is encased within a settable material such as concrete, the body 2 keys into the settable material upon hardening of the settable material.

More particularly, the keying resists movement of the body 2 relative to the hardened settable material in the direction of the elongate dimension of the body 2. That is, if the body 2 of firestopping device 1 as illustrated for example in figure 1 is encased in a vertical orientation within a flooring concrete slab, then the keying will resist vertical movement of the body 2 relative to the concrete once it has hardened. Similarly, if the body 2 of firestopping device 1 is encased in a horizontal orientation within a walling concrete slab, then the keying will resist horizontal movement of the body 2 relative to the concrete once it has hardened.

In the illustrated embodiment the keying formation is a plurality of projections in the form of fasteners such as rivets 12. At each of the joints 14, five rivets 12 are used to connect the planar panels that form the sidewalls 8 of the body 2. The joints 14 comprise 45º bends that form angled sections 16 at either end of each of the sidewalls 8. Five holes are drilled at regular intervals along each of the angled sections 16. Each of the angled sections 16 is mated together with a like angled section 16 of an adjacent sidewalls 8 such that the holes align and the rivets are inserted through the holes and then riveted. As shown for example in figure 1, the exposed portions of the rivets 12 have a component of projection that is orthogonal to the body 2. In other words, the exposed ends of the rivets 12 protrude from at least one side of the joints 14 and this provides a significant component of the keying of the body 2 with the settable material.

The firestopping device 1 is designed for use in a method of constructing a barrier , such as a concrete floor or wall, which is required to have a fire rated passageway extending there through. As shown for example in figure 10, the firestopping device 1 is positioned within a space 18 into which a settable material is to be poured. As is well known to those skilled in the art of laying concrete slabs, the bottom of the space 18 is defined by a horizontal planar piece of formwork, such as wooden panel 19. Reinforcing bars 23 may also be deployed within the space 18 in the known manner.

To withstand the forces that will be applied to the body 2 when the concrete is poured, the firestopping device 1 is attached to the formwork panel 19 by fasteners, such as nails, screws or the like. The fasteners are driven through the holes 11 in the attachment flange 10 and into formwork panel 19 so as to affix the firestopping device 1 in the desired position.

Next the concrete 21 is poured into the space 18 to the desired thickness, as shown for example in figure 11. This encases at least a proportion of the body 2 within the concrete 21 to yield the above-described keying once the concrete has dried.

Once the formwork has been removed, the first and second openings 3 and 4 are disposed on either side of the concrete and the internal volume of the body 2 defines the fire rated passageway through the barrier 20. The services may now be routed through the passageway and then the openings 3 and 4 are sealed with one or two pieces of graphite impregnated foam 22. In an alternative embodiment, brushes are disposed at each of the openings 3 and 4 instead of, or in addition to, the use of the graphite impregnated foam 22 or other fire resistant foam.

Optionally, lengths of thermally insulative wrap, such as ceramic fibre wrap, can be fitted around the services externally to the firestopping device 1. The thermally insulative wrap may be held in place by a variety of methods such as the use of metal fixings and/or adhesive tape.

While a number of preferred embodiments have been described, it will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the invention without departing from the spirit or scope of the invention as broadly described. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.

Claims (15)

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:

1. A firestopping device including: a body having a first opening at a first end, a second opening at a second end and an internal volume intermediate the first and second ends, the internal volume and each of the openings being sized such that at least one service may extend through the firestopping device; an intumescent material being housed within the internal volume, the intumescent material being responsive to heat so as to swell within the internal volume; and at least one attachment formation being disposed at or adjacent to the first opening, the attachment formation being configured for attachment of the firestopping device to an external surface.

2. A firestopping device according to claim 1 wherein the attachment formation is an outwardly extending flange disposed at the first opening.

3. A firestopping device according to claim 2 wherein the outwardly extending flange includes a plurality of holes each being sized so as to receive a fastener extending there through.

4. A firestopping device according to claim 2 or 3 wherein the outwardly extending flange is substantially orthogonal to the body.

5. A firestopping device according to any one of the preceding claims wherein an external surface of the body includes keying formations such that when at least part of the body is encased within a settable material, the body keys into the settable material upon hardening of the settable material.

6. A firestopping device according to claim 5 wherein the body defines an elongate dimension and wherein the keying resists movement of the body relative to the hardened settable material in the direction of the elongate dimension.

7. A firestopping device according to claim 5 or 6 wherein the keying formation is a plurality of projections having a component of projection that is orthogonal to the body.

8. A firestopping device according to claim 7 wherein the plurality of projections are a plurality of fasteners used to connect planar panels so as to form the body.

9. A firestopping device according to claim 8 wherein the fasteners are rivets.

10. A method of constructing a barrier having a fire rated passageway extending there through, the method including the steps of: providing a firestopping device including a body having a first opening at a first end, a second opening at a second end and an internal volume intermediate the first and second ends, the internal volume and each of the openings being sized such that at least one service may extend through the firestopping device, an intumescent material being housed within the internal volume, the intumescent material being responsive to heat so as to swell within the internal volume; positioning the firestopping device within a space into which a settable material is to be poured; and pouring the settable material into the space such that at least a proportion of the body is encased within the settable material and such that the first and second openings are disposed on either side of the settable material such that the internal volume defines the fire rated passageway.

11. A method according to claim 10 wherein at least one attachment formation is disposed at or adjacent to the first opening, the attachment formation being configured for attachment of the firestopping device to an external surface.

12. A method according to claim 11 wherein the space is at least partly defined by an external surface and wherein “positioning the firestopping device within a space into which a settable material is to be poured” includes affixing the attachment formation to the external surface.

13. A method according to any one of claims 10 to 12 wherein an external surface of the body includes keying formations and wherein, once the at least a proportion of the body has been encased within the settable material and the settable material has hardened, the body is keyed into the hardened settable material.

14. A method according to claim 13 wherein the keying resists movement of the body relative to the hardened settable material in the direction of the elongate dimension.

15. A barrier constructed in accordance with the method of any one of claims 10 to 14.