GB2427624A

GB2427624A - Building construction

Info

Publication number: GB2427624A
Application number: GB0612837A
Authority: GB
Inventors: David Jaina
Original assignee: T D I
Current assignee: T D I
Priority date: 2005-06-28
Filing date: 2006-06-28
Publication date: 2007-01-03
Also published as: GB0612837D0; GB0513206D0

Abstract

The invention relates to an apparatus for providing a fire retardant barrier for a cavity 2 in a cavity wall building construction 3 (4 figure 2) and comprises a cavity closer 5 and an integral damp proof course (DPC) 6. The DPC is preferably a separate flexible membrane secured to the cavity closer by adhesive or mechanical securing means forming a combined structure. The cavity closer 5 may comprise a fire retardant material and may further comprise acoustic insulation material for sound proofing purposes.

Description

BUILDING CONSTRUCTION

The invention relates to a building construction, particularly to apparatus for providing a fire retardant barrier for a cavity in a cavity wall building construction.

Building constructions often include an external wall of cavity construction namely one that has an inner skin and an outer skin, the skin being separated by a cavity, which usually has a minimum width between the skins of 50mm. The cavity helps to provide a thermal break between the skins and so assists in obviating heat transfer to or from a room having a boundary defined by the inner skin, and ambient air outside the outer skin. However, moisture tends to collect in the cavity, so damp proof course (DPCs) are often installed to shed water from the cavity to the outer skin, away from the inner skin, which moisture would otherwise tend to seep through the inner skin and cause damage to paint etc. on the wall of the room. Such DPCs are not fire resistant. The cavities themselves are a potential fire hazard in that particularly in multi storey buildings, as they extend the full height of the building they can act as "chinmeys" up which smoke, flames etc. can pass from a lower to a higher floor or storey of the building, so spreading fire when it breaks out.

It is an object of the invention to seek to provide a barrier for providing fire protection in a cavity wall building construction.

According to a first aspect of the invention there is provided apparatus for providing a fire retardant barrier for a cavity in a cavity wall building construction, comprising a cavity closer and an integral damp proof course (DPC).

Using an embodiment of the invention it is possible to provide a one hour fire prevention, it being understood that the term "fire-retardant" used herein means "fire prevention", "fire resistant", "smoke resistant" and the like.

The DPC may comprise a damp proof membrane.

The DPC may suitably be flexible.

The DPC may suitably be flexible. This provides for ease of installation.

The DPC may be initially separate and subsequently secured to the cavity closer. This provides for ease of construction.

The DPC and cavity closer may be secured together with adhesive, whereby to provide a combined structure.

Alternatively, the DPC and cavity closer may be secured together by mechanical securing means, for example, rivets, staples, screws, pins or nails.

Again, the DPC and cavity closer may be secured together by fusion of the DPC, or by respective complementary interengageable surface profile means. Thus such means may be a dove-tail joint kind of construction.

The cavity closer may comprise a fire retardant material.

The cavity closer and/or the DPC may additionally or alternatively comprise a sound absorbent or acoustic insulation material. Additionally, or alternatively, the fire retardant material and/or the DPC may also be sound absorbent or acoustic insulation material.

According to a further aspect, the invention provides a building construction including a cavity wall and apparatus as hereinbefore defined installed in the cavity.

The damp proof course may have a part which extends over part of the external face of an inner skin of the wall, or alternatively may have a part which is engaged in the inner skin of the wall.

The apparatus may be installed at or adjacent a junction between a floor of the building and the wall.

The inner skin may comprise steel or a timber frame, or masonry.

Apparatus embodying the invention is hereinafter described, by way of example, with reference to the accompanying drawings.

Fig. 1 is a schematic cross-sectional view through one cavity wall building construction with apparatus according to the invention installed therein; and Fig. 2 is a similar view to that of Fig. 1 of another cavity wall building construction with apparatus according to the invention installed therein.

In the drawings, like parts are indicated by like reference numerals.

Referring to the drawings there is shown apparatus 1, 10 for providing a fire retardant barrier for a cavity 2 in a cavity wall building construction 3, 4 comprising a cavity closer 5 and an integral damp proof course 6 (DPC).

The outer skin or leaf 7 of the cavity wall 3, 4 is formed of masonry or precast panels and is separated from an inner skin or leaf of the wall 8, which forms a boundary for a room 11, by the cavity of minimum width 50mm.

There is a floor 9 between the room 11 and a lower room 12, the inner skin 8 not being continuous between storeys. There are various elements of the cavity wall construction, such as flanking strip 13 of minimum width 5mm (Fig. I) and gypsum based board 14 of nominal weight 8kg/m2, which wall runs vertically over all the storeys of the building construction and thus presents a fire hazard as flames, sparks, smoke can pass from storey to storey. In order to seek to obviate this disadvantage the barrier 1, 10 is installed in the cavity 2 at a level adjacent a floor deck or slab 9, the barrier 1, 10 being a single unit which is installed in the cavity during building construction. The DPC 6 is a flexible membrane, for example of polyethylene and has a part 6a secured to the cavity closer 5, and a part 6b which extends across the cavity 2 and a part 6c which is secured by suitable means to the outer face (i.e. adjacent the cavity) of the inner skin 8 of the cavity wall. The DPC is shown in dashed lines in the Figures.

In Fig. 2, the part 6c is incorporated in the inner skin 8, for example in a layer of mortar between the floor deck or slab 9 and the lower part of the inner skin above the floor.

In each case the DPC is flexible. The part 6a is secured to the cavity closer 5 by any suitable means, for example adhesive, by melting and resetting, by rivets, staples, screws, pins or nails, or by for example interengageable surface profile means. Thus the part 6a may have dovetail members which slide into dove-tail shaped grooves on the cavity closer 5. This provides a secure fitting.

Further, one or both of the cavity closer S and DPC 6 of an embodiment of the invention provide an accoustic barrier i.e. provide sound proofing, or an accoustic barrier, between floors, provided by, for example, a sound insulation material.

Alternatively, a separate sound insulation material (not shown) may be provided, in addition to the cavity closer 5 and DPC 6.

In every case the DPC or membrane 6 sheds moisture condensing in the cavity 2 to the outside of the building construction via the part 6b which directs the moisture downwardly and outwardly, away from the inner skin 2, while the cavity closer 5 prevents passage of heat, flames, sparks, smoke and the like upwardly along the cavity, thus protecting upper storeys from fire below.

Claims

1. Apparatus for providing a fire retardant barrier for a cavity in a cavity wall building construction, comprising a cavity closer and an integral damp proof course (DPC).

2. Apparatus according to Claim 1, the DPC comprising a damp proof membrane.

3. Apparatus according to Claim 2, the DPC being flexible.

4. Apparatus according to any preceding claim, the DPC being initially separate and subsequently secured to the cavity closer.

5. Apparatus according to Claim 4, the DPC and cavity closer being secured together with adhesive, whereby to provide a combined structure.

6. Apparatus according to Claim 4, the DPC and cavity closer being secured together by mechanical securing means.

7. Apparatus according to Claim 6, the mechanical securing means comprising rivets.

8. Apparatus according to Claim 6, the mechanical securing means comprising staples.

9. Apparatus according to Claim 6, the mechanical securing means comprising screws.

10. Apparatus according to Claim 6, the mechanical securing means comprising pins or nails.

11. Apparatus according to Claim 4, the DPC and cavity closer being secured together by fusion of the DPC.

12. Apparatus according to Claim 4, the DPC and cavity closer being secured together by respective complementary interengageable surface profile means.

13. Apparatus according to Claim 12, the said means comprising a dovetail joint kind of construction.

14. Apparatus according to any preceding claim, the cavity closer comprising a fire retardant material.

15. Apparatus according to any preceding claim, further comprising an acoustic insulation material.

16. Apparatus according to any proceeding claim, wherein the cavity closer andlor the DPC comprise acoustic insulation material to provide sound proofmg.

17. Apparatus for providing a fire retardant barrier for a cavity in a cavity wall building construction, substantially as hereinbefore described, with reference to the accompanying drawings.

18. A building construction including a cavity wall, and apparatus according to any preceding claim installed in the cavity.

19. A building construction according to Claim 18, the damp proof course having a part which extends over part of the external face of an inner skin of the wall.

20. A building construction according to Claim 18, the damp proof course having a part which is engaged in the inner skin of the wall.

21. A building construction according to any of claims 18 to 20, the apparatus being installed at or adjacent a junction between a floor of the building and the wall.

22. A building construction according to claim 21, the inner skin comprising steel or a timber frame, or masonry.

23. A building construction including a cavity wall, substantially as hereinbefore described with reference to the accompanying drawings.