GB2377379A

GB2377379A - Fire resistant barrier

Info

Publication number: GB2377379A
Application number: GB0116817A
Authority: GB
Inventors: Derek Alfred Ward
Original assignee: Environmental Seals Ltd
Current assignee: Environmental Seals Ltd
Priority date: 2001-07-10
Filing date: 2001-07-10
Publication date: 2003-01-15
Anticipated expiration: 2021-07-10
Also published as: EP1404414A1; WO2003006109A1; GB2377379B; GB0116817D0

Abstract

A fire-resistant barrier for roof spaces comprises a fire curtain impregnated or coated with a quantity of an intumescent material. An intumescent-containing adhesive is provided to adhere the fire curtain to one or more roof trusses or party walls of the roof space. A plurality of battens coated with or produced from an intumescent material are provided to secure the fire curtain to roof trusses or party walls of the roof space, and pieces of fire retardant intumescent impregnated flexible foam or sponge, rockwool, ceramic felt or compressed glass wool are provided to fill all gaps present between the fire curtain and the surrounding roof structure to seal the adjoining roof spaces one from the other.

Description

FIRE RESISTANT BARRIER This invention relates to fire-resistant barriers for preventing the spread of fire and smoke in roof spaces. More especially, the invention relates to fire-resistant barriers for preventing the spread of fire and smoke between the roof spaces of adjoining terraced buildings. The invention also has application for preventing the spread of fire and smoke in relatively large roof spaces.

Presently a fire in one building of a terrace quickly spreads to the adjoining buildings particularly through the neighbouring roof spaces. One major cause of a fire spreading is the use of flammable roofing felt and timber battens. Even in cases where roofing felt having Class D and Class 1 protection, the battens which hold the felt in place define paths for the spread of fire. The same problems apply for buildings having substantial roof spaces.

The present invention sets out to provide a fire-resistant barrier which operates to prevent the spread of fire between adjoining roof spaces for an enhanced period of time, especially periods in excess of one hour.

According to the present invention in one aspect, there is provided a fire-resistant barrier for roof spaces, the barrier comprising a fire curtain impregnated or coated with a quantity of an intumescent material, an intumescent-containing adhesive for adhering the fire curtain to one or more roof trusses or party walls of the roof space, a plurality of battens coated with or produced from an intumescent material for securing the fire curtain to roof trusses or party walls of the roof space, and pieces of fire retardant intumescent impregnated flexible foam or sponge, rockwool, ceramic felt or compressed glass wool for filling all gaps present between the fire curtain and the surrounding roof structure to seal the adjoining roof spaces one from the other.

In another aspect, there is provided a method of creating a fire barrier between neighbouring roof spaces lined with roofing felt, the method comprising the steps of cutting through all roofing felt at the point at which the barrier is to be erected to expose all roofing tiles, battens of the roof structure in the area in which the barrier is to be erected, adhering to the exposed roof structure a fire curtain containing or coated with an intumescent material using an intumescent containing adhesive, attaching the sides of the fire curtain to the exposed roof structure using battens coated with or constructed essentially from an intumescent material, and filling all gaps present between the adjoining roof spaces with pieces of flexible cellular fire-retardant foam or sponge, or rockwool or ceramic felt or compressed glass wool to create an effective seal between the divided roof spaces.

In a further aspect, the invention provides a method of erecting a fire barrier between a roof truss and party wall of a roof space lined with roofing felt, the method comprising the steps of cutting and/or removing all roofing felt between the party wall and the roof truss, adhering to the roof truss using an intumescent-containing adhesive a fire curtain impregnated or coated with an intumescent material. extending the curtain towards and over the party wall and adhering the same to the party wall using an intumescentcontaining adhesive whereby the curtain defines a fire barrier which extends across the full width of the roof space and along the entire roof interior surface between the truss and the party wall, and securing the curtain to the truss and/or the party wall with battens either coated with or essentially comprising intumescent material.

The fire curtain may include or be coated with a mixture of particular ceramic material, an intumescent substance and a binder. The intumescent material may comprise exfoliating graphite and/or sodium silicate in granular and/or powder form. The sheet containing the intumescent material may comprise a non-woven mat or sheet. The initial thickness of the sheet is preferably from 2 to 3mm and the sheet thickness when intumesced preferably exceeds 25mm When a fire-retardant foam or sponge, it may be coated on at least one of its surfaces with a primer solution including a sealant and a flowable coating of fire-retardant material. In this embodiment, the primer solution operates to close the open pores of the

coated surface of the rib and provides a bond to which the fire-retardant coating can adhere. The primer solution may comprise an aqueous solution of an acrylic polymer, including ammonium polyphosphate. The fire-retardant coating may comprise a chlorinated vinyl copolymer system which includes a quantity of ammonium polyphosphate, zinc borate, or magnesium and calcium carbonates. The foam or sponge may comprise polyurethane or a silicone coated with silane primer.

The following is one example of a fire resistant barrier in accordance with the invention created within a roof space in the vicinity of a party wall between two adjoining terraced houses. This is given by way of example only.

As is common with the vast majority of terraced and semi-detached properties, the entire roof space spanning each property of the terrace is lined with roofing felt held in position between roof trusses and roofing tiles of the roof structure by wooden battens.

Party walls are constructed to divide the entire roof space into separate sections so that each house of the terrace has its own roof space for storage or other purposes. Party walls are generally constructed by securing sheets of plasterboard to roof trusses.

The continuous nature of the roofing felt and the wooden battens used to retain the felt in place represent potential fire hazards. Thus, if a fire breaks out in one property of a terrace, the continuous lengths of roofing felt and the battens can encourage the spread of fire from one roof space to an adjoining roof space, and so on. A fire in one property of a terrace can-and often does-lead to severe fire damage to all properties of that terrace.

The same considerations apply for houses having large roof spaces to the extent that a fire in one part of the building can quickly spread to other parts through roofing felt and battens.

To create the fire barrier of this example, the roofing felt was cut tight up against the party wall and against the neighbouring roof truss remote from the party wall to create a continuous break in the roofing felt.

A fire curtain impregnated with a material which intumesces in the presence of fire was then adhered to the truss using an intumescent-containing adhesive and then firmly secured to the truss using fireproofed battens and large headed clout nails.

All gaps between the top and sides of the party wall and the roof tiles were then filled with a fire-proofed sponge material which expands slightly in the presence of fire.

Alternatively rockwool slabs, ceramic felt or compressed glass wool can be used for this purpose.

The fire curtain was then pulled along the underside of the exposed roof tiles and secured to the party wall using the tumescent-containing adhesive and fire-proofed battens.

In this way an effective fire barrier was created between the adjoining roof space sections.

It will be appreciated that the foregoing is merely exemplary of fire resistant barriers in accordance with the invention and that various modifications can be made thereto without departing from the true scope of the invention.

Claims

CLAIMS 1. A fire-resistant barrier for roof spaces, the barrier comprising a fire curtain impregnated or coated with a quantity of an intumescent material, an intumescent- containing adhesive for adhering the fire curtain to one or more roof trusses or party walls of the roof space, a plurality of battens coated with or produced from an intumescent material for securing the fire curtain to roof trusses or party walls of the roof space, and pieces of fire retardant intumescent impregnated flexible foam or sponge, rockwool, ceramic felt or compressed glass wool for filling all gaps present between the fire curtain and the surrounding roof structure to seal the adjoining roof spaces one from the other.
2. A fire curtain as claimed in claim I which includes or is coated with a mixture of particulate ceramic material, an intumescent substance and a binder.
3. A fire curtain as claimed in claim 2 wherein the intumescent substance comprises exfoliating graphite and/or sodium silicate in granular and/or powder form.
4. A fire curtain as claimed in any one of the preceding claims wherein the sheet containing the intumescent material comprises a non-woven mat or sheet.
5. A fire curtain as claimed in claim 4 wherein the initial thickness of the sheet is from 2 to 3mm and the sheet thickness when intumesced preferably exceeds 25mm
6. A fire curtain as claimed in claim 1 wherein the fire-retardant foam or sponge is coated on at least one of its surfaces with a primer solution including a sealant and a flowable coating of fire-retardant material.
7. A fire curtain as claimed in claim 6 wherein the primer solution comprises an aqueous solution of an acrylic polymer, including ammonium polyphosphate.

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8. A fire curtain as claimed in claim 6 or claim 7 wherein the fire-retardant coating comprises a chlorinated vinyl copolymer system which includes a quantity of ammonium polyphosphate, zinc borate, or magnesium and calcium carbonates.
9. A fire curtain as claimed in any of the claims 6 to 8 wherein the foam or sponge comprises polyurethane or a silicone coated with silane primer.
10. A method of creating a fire barrier between neighbouring roof spaces lined with roofing felt at the point at which the barrier is to be erected, the method comprising exposing all roofing tiles, battens of the roof structure in the area in which the barrier is to be erected, adhering to the exposed roof structure a fire curtain containing or coated with an intumescent material using an intumescent containing adhesive, attaching the sides of the fire curtain to the exposed roof structure using battens coated with or constructed essentially from an intumescent material, and filling all gaps present between the adjoining roof spaces with pieces of flexible cellular fire-retardant foam or sponge, or rockwool or ceramic felt or compressed glass wool to create an effective seal between the divided roof spaces.
11. A method or erecting a fire barrier between a roof truss and party wall of a roof space lined with roofing felt, the method comprising the steps of cutting and/or removing all roofing felt between the party wall and the roof truss, adhering to the roof truss using an intumescent-containing adhesive a fire curtain impregnated or coated with an intumescent material, extending the curtain towards and over the party wall and adhering the same to the party wall using an intumescent-containing adhesive whereby the curtain defines a fire barrier which extends across the full width of the roof space and along the entire roof interior surface between the truss and the party wall, and securing the curtain to the truss and/or the party wall with battens either coated with or essentially comprising intumescent material.