Fire Protection - Insulation

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Structural steel requires fire protection because ... structural integrity of the building. Protecting the ..... When exposed to 90% relative humidity and. 20ºC ...
Section 6.0 Fire Protection

Structural steelwork Product: Knauf Fireboard

Fp01

Structural steelwork Product: Rocksilk FireTech Slab

Fp02

Mezzanine floors Product: Rocksilk FireTech Slab Fp03

Small cavity barriers Product: Earthwool Cavity Barrier Fp04

Large cavity barriers Product: Rocksilk Smoke and Fire Barrier Fp05

Refurbishment of timber separating/internal floor Product: Earthwool Flexible Slab Fp06

Steel Duct Encasement Product: Rocksilk Pyroduct Slab Fp07

6.1

Fire Protection

Fire protection of structural steel Fire protection design

Knauf Insulation are members of the Association for Specialist Fire Protection, and our fire protection products are listed in the Yellow Book, which presents economical methods for the fire protection of structural steelwork to provide compliance with Building Regulations

Structural steel requires fire protection because it loses structural strength at temperatures that can be rapidly reached in a building fire. This will consequently have a negative impact on the structural integrity of the building. Protecting the structural steel from the heat of a fire will delay the onset of this loss of strength and the possible collapse of the building. This is essential because it allows extra time for both the occupants of the building to escape and fire services to tackle the fire. It could also prevent the actual collapse of the building minimising insurance losses. Building Regulations covering fire safety are concerned with the preservation of life. With the increasing use of structural steel in construction, designers need fire protection solutions that provide a combination of fast installation and cost-effectiveness whilst achieving the desired finish. Whatever the application Knauf Insulation has a range of board products and systems to cater for any project. When used for the fire protection of structural steelwork, board systems offer several compelling advantages over site applied paint and spray coating systems. Board systems: •

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Are manufactured to factory tolerances – this enables the specifier to be certain that the correct thickness of fire protection is being applied, by simply checking the thickness of materials supplied

• Can be installed prior to the building being sealed and made watertight, in all temperature and humidity conditions – this is in contrast to paint and sprays which are often restricted by normal UK winter conditions, causing potential delay to site programs • Are fast, clean, and dry to install, with negligible dust levels, allowing other trades to work in close proximity • Are quick and easy to check (by visual inspection) that all relevant areas have been protected • Are fully compatible with drylining systems and allow easy integration with partitioning schemes

Fire protection

Any steel section which is an element of structure and is deemed by any of the following regulations to require fire resistance can be protected with a fire protection system of dense rock mineral wool slabs or fibre reinforced gypsum based boards. 1. The Building Regulations (England and Wales) Approved Document B (Fire Safety) – Volumes 1 and 2 (2006)

5. Loss Prevention Council Code of Practice for Construction of Buildings Steel sections can include universal beams, columns and joists (plain and castellated), structural and rolled tees, angles, channels and round, square or rectangular hollow sections.

Benefits

Both rock mineral wool slabs and fibre reinforced gypsum boards offer a number of advantages for the fire protection of structural steelwork that make them ideal for fast track projects. Rock mineral wool • Lightweight product – at less than half the weight of calcium silicate slabs – rock mineral wool fire protection boards are easy to handle and fit on site particularly for overhead work • Ease of cutting and fixing: Rock mineral wool slabs are easy to cut with either a saw or a sharp knife, furthermore there are four fixing methods, all involve square edge butt joints between the boards which enables a fast and simple system to be installed without delaying other trades and activities

2. The Building (Scotland) Regulations, Technical Booklets, Section 2, 2011

Fibre reinforced gypsum • Smooth surface – only requires decorative finishes for completion

3. The Building Regulations (Northern Ireland) Technical Booklet E, 2005

• Robust and impact resistant – ideal for columns and all exposed surfaces

4. The Building Regulations (Republic of Ireland) Technical Guidance Document B (2006)

• Easy to cut to size – can be scored and snapped to speed up cutting and reduce dust levels

Technical Advice and Support Centre 01744 766666

www.knaufinsulation.co.uk

6.1

Fire Protection

Fire protection Solution optimiser and pathfinder­ Key

Find online. Visit knaufinsulation.co.uk and key in construction code to find the



most up to date information on your chosen solution.

Pb01

Fire protection Period of fire resistance (mins)

Knauf Insulation solution

0 mins

30 mins

60 mins

90 mins

120 mins

150 mins

180 mins

210 mins

240 mins

Structural steelwork Product: Knauf Fireboard See page: 268 Fp01

Structural steelwork Product: Rocksilk FireTech Slab See page: 274 Fp02

Mezzanine floors Product: Rocksilk FireTech Slab See page: 280 Fp03



Fp04

6.1

Large cavity barriers Product: Rocksilk Smoke and Fire Barrier See page: 286 Fp05

Refurbishment of timber separating/ internal floor Product: Earthwool Flexible Slab See page: 292

Fp06

Steel Duct Encasement Product: Rocksilk Pyroduct Slab See page: 294 Fp07

Technical Advice and Support Centre 01744 766666

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Fire Protection

Fire protection Structural steelwork Knauf Fireboard NEW BUILD

Fp01

• Quick and easy to install • Dry fix system providing up to 2 hours fire protection



• Combined fire protection and aesthetic finish



Knauf Drywall Screws at maximum 100mm centres into backing strips Knauf Fireboard

Knauf Fireboard • Non-combustible with a Euroclass A1 reaction to fire rating • Zero Ozone Depletion Potential (ODP) • Zero Global Warming Potential (GWP)

Abutment angles: light gauge steel angle provides support at soffit and wall junctions. Fixed to adjoining soffit or section flange.

Products

Typical construction

Knauf Fireboard is a gypsum based board specially developed for high performance lining and encasement, providing up to two hours of fire protection.

Knauf Fireboard is used in frameless encasements. The product has been specially developed to accept direct edge fixings. Casings consist of Knauf Fireboard screwed or stapled to itself at abutting corners.

Knauf Fireboard has a high quality white smooth surface finish ideally suited as a self finish. Its surface allows direct decoration with most paint finishes or it can be plastered*. Knauf Drywall Screws are gold passivated screws with spoon tips and ‘hi-low’ threads. Knauf Fireboard can also be installed using proprietary staples. *Consult plaster manufacturer prior to application of plaster finish.

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For steelwork encased on all four sides, Knauf Fireboard is fixed at each corner directly through the material, independent of the column or beam. For partial encasement, involving wall or ceiling abutments, Knauf Fireboard is fixed to light gauge steel angles. Knauf Insulation recommend the use of Knauf Drywall Screws, essential for fast construction, solid fixing and tightly closed edge joints.

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Edge fix the boards using either Knauf Drywall Screws at maximum 150mm centres or proprietary staples at 120mm centres.

REFURB

Fire Protection

6.1

Typical specification

Knauf Fireboard, ...…mm thick, to be used to provide fire protection to structural steelwork.

Stagger joints by 300mm minimum

Knauf Fireboard casing

It is to be installed on beam*/column* as a complete 4 sided*/3 sided*/2 sided* encasement (*specifier’s choice) to provide ......minutes fire protection as detailed in the Installation section. Alternatively, consult the National Building Specifications, Standard version clause/clauses… K10/265…………… Knauf Insulation specification clauses can be downloaded from knaufinsulation.co.uk/nbs

Direct edge-fixing with Knauf Drywall Screws at 200mm centres or proprietary staples at 120mm centres

Fire performance The system can provide up to 2 hours fire protection. For precise calculation of fire protection periods, please contact Knauf Insulation Technical Advice and Support Centre.

Operating temperatures Continuous long term exposure to temperatures over 50ºC can induce a change of state which would reduce the physical performance and serviceability of the boards.

Knauf Fireboard is non-combustible to BS 476: Part 4: 1970 (1984) and Class 1 surface spread of flame to BS 476: Part 7: 1997. Knauf Fireboard complies with the Class ‘0’ requirements of the Building Regulations when tested to BS 476: Part 6: 1989 and Part 7: 1997 and with the limited combustibility described in the Building Regulations.

Health and safety Knauf Fireboard must be installed with care. Ensure adequate ventilation during installation, particularly when cutting boards. Avoid harsh body contact with sharp cut edges of metal components. Refer to Knauf Insulation Material Safety Data Sheets and to the Health and Safety Executive publications.

Humidity Constant humidity over 95% or subjection to continuous water will reduce the serviceability of the boards.

For Hp/A tables please visit knaufinsulation.co.uk

Technical Advice and Support Centre 01744 766666

6.1

Performance

www.knaufinsulation.co.uk

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6.1

Fire Protection

Fire protection Installation of column system

Installation sequence

1

Cut

two boards to the width of the column flange.



2



Hold in place the first 2 boards with clamps.

3



 fter measuring the A size of the remaining 2 sides, cut another two to the depth of the column plus twice the thickness of the board.

4



 pply the remaining A boards, adjusting the length of adjoining boards to ensure that board joints are staggered by at least 300mm.

Installation Steelwork encasements must be installed in full accordance with Knauf Insulation’s recommendations and in compliance with BS 8212: 1995 and BS 8000: Part 8: 1994. The installation procedures outlined here relate to normal single layer applications.

Partial column encasement Assuming a typical three-sided encasement where one of the column flanges straddles a wall, follow the same procedure as outlined for four-sided encasement with the following differences:

Knauf Drywall Screws Knauf Drywall Screws should penetrate into the casing by at least 30mm.

• Fix 25 x 25mm light gauge steel angles, in continuous lengths, to either the abutting wall face or the inner flange of the column. Use appropriate proprietary fixings at 600mm centres

Four-sided column encasement • Cut two boards to the width of the column flange. Cut another two to the depth of the column plus twice the thickness of the board • Adjust the length of adjoining boards to ensure that board joints are staggered by at least 300mm • Edge-fix the boards using either Knauf Drywall Screws at 200mm centres or proprietary staples at 120mm centres

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Double layer application Install the first layer as described for either full or partial encasement. Secure the second layer to the first with fixings spaced as for the first layer but avoid coincident fixing positions. It is good practice that board joints are staggered – as with the first layer – between adjoining boards and also between the two layers. In the case of structural steelwork, double layer encasement will obviate the need for joint backing strips.

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5

Edge-fix the boards using either self drilling Knauf Fireboard Gripper Screws at 200mm centres or proprietary staples at 120mm centres. Knauf Fireboard Gripper Screws should penetrate into the casing by at least 30mm

Fire Protection

6.1

Fire protection Installation of beam system

Installation sequence

1



Install continuous lengths of 25 x 25mm angle using appropriate proprietary fixings at 600mm centres, fix further lengths of 25 x 25mm angle at any end abutment.

2



Cut two boards to the depth of the section plus twice the board thickness plus l0mm.





Screw-fix these to the angles at 150mm centres with 35mm Knauf Drywall Screws.

3







Cut a soffit board to the width of the steel flange. The length of this board must differ from the side boards to ensure adjacent board joints are staggered by at least 300mm.

Edge-fix horizontal board to the two vertical boards using either Knauf Fireboard Gripper Screws at 150mm centres or proprietary staples at 120mm centres.

4





Cut board off-cuts 100mm wide as joint backing strips. Fit these, half lapped, behind all butt joints at the sides and soffit of the beam.

Fix with Knauf Fireboard Gripper Screws at maximum 100mm centres.

Assuming a typical three-sided encasement, where a beam is exposed directly below a level soffit, fix light gauge steel angles to either the adjoining soffit or the top flange of the beam. Install continuous lengths of 25 x 25mm angle using appropriate proprietary fixings at 600mm centres. • Fix further lengths of 25 x 25mm angle at any end abutment • Cut two boards to the depth of the section plus twice the thickness of the board plus l0mm. Screw-fix these to the angles at 150mm centres with 35mm Knauf Drywall Screws • Cut a soffit board to the width of the steel flange. The length of this board must differ from the side boards to ensure adjacent board joints are staggered by at least 300mm. Edge-fix this horizontal board to the two vertical boards using either self-drilling Knauf Drywall Screws at 150mm centres or staples at 120mm centres

• Cut board off-cuts 100mm wide as joint backing strips. Fit these, half-lapped, behind all butt joints at the sides and soffit of the beam fixed with Knauf Drywall Screws at maximum 100mm centres

nominal 150mm centres, screw lengths should be equal to the thickness of the second layer, plus 30mm. Where two different thicknesses of Fireboard are applied, the thicker layer is installed first.

Double layer application Install the first layer as described for either full or partial encasement. Secure the second layer to the first with fixings spaced as for the first layer but avoid coinciding fixing positions.

6.1

Beam encasement

It is good practice that board joints are staggered – as with the first layer – between adjoining boards and also between the two layers. In the case of structural steelwork, double layer encasement will obviate the need for joint backing strips. The second layer of boards across the webs are fixed to the angle attached to the upper flange using 55mm long Knauf Drywall Screws at 150mm centres and the second layer across the bottom flange using Knauf Drywall Screws at

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Fire Protection

Fire protection Application details for beams

Beam with partition abutment

25 x 25mm angle secured to top flange of beam, or alternatively to soffit Knauf Drywall Screws at maximum 100mm centres

Fireboard casing Backing strip 10mm gap Direct edge fixing with Knauf Drywall Screws at maximum 150mm centres or staples at 120mm centres

C-Stud partition with standard U-Channel head track

Beam with wall abutment

25 x 25mm angle secured to top flange of beam, or alternatively to soffit

Knauf Drywall Screws at maximum 100mm centres

Fireboard casing

Direct edge fixing with Knauf Fireboard Gripper Screws at maximum 150mm centres or staples at 120mm centres

Continuous 25 x 25mm Knauf Fireboard Angle secured to substrate using appropriate fixings Masonry wall

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Technical Advice and Support Centre 01744 766666

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Fire Protection

6.1

Column with partition abutment Direct edge fixing with Knauf Drywall Screws at maximum 200mm centres or staples at 120mm centres

Knauf C-Stud toggle-fixed to Knauf Fireboard casing

Knauf Wallboard not fixed to this C-Stud

Column with wall lining abutment

Continuous 25 x 25mm Knauf Fireboard angle at each corner

6.1

Knauf Wallboard not fixed to this C-Stud

Direct edge fixing with Knauf Drywall Screws at maximum 200mm centres or staples at 120mm centres

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Fire Protection

Fire protection Structural steelwork Rocksilk FireTech Slab REFURB

Fp02 Flexible system with four installation

• methods

• Maintenance free, passive system • Clean installation process with negligible dust generation

Rocksilk FireTech Slab



Rocksilk FireTech Slab • Non-combustible with a Euroclass A1 reaction to fire rating • Zero Ozone Depletion Potential (ODP) • Zero Global Warming Potential (GWP)

Pig tail screws

Noggin of Rocksilk FireTech Slab or Rocksilk FireTech Dry Fix Noggin Slab

Product  ocksilk FireTech Slab is a dense rock mineral R wool slab. It is available unfaced or faced with a bright Class ‘0’ reinforced aluminium foil, for applications above clean rooms, within air plenums, or for aesthetic purposes. Plaster manufacturers advice and guidance should be followed regarding pre-treatment of Rocksilk FireTech Slabs before application of plaster finishes Rocksilk FireTech Dry Fix Noggin Slab is an ultra high density rock mineral wool slab used for the noggin in the Rocksilk FireTech Dry Fix Noggin System.

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Typical construction

Installation

The exposed surfaces of any steel section are fully enclosed in Rocksilk FireTech Slab, using any of the fixing systems shown on the following pages.

Rocksilk FireTech Slab can be used with four types of fixing methods for the fire protection of structural steelwork and each system has its own performance characteristics.

Rocksilk FireTech Slab can be used to provide up to 4 hours fire protection to structural steel and cast iron columns, beams and trusses. Steel sections may include universal beams, columns and joists (plain and castellated), structural and rolled tees, angles, channels and round, square or rectangular hollow sections.

Fixing methods:

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• Dry Fix Noggin System • Adhesive Noggin Fixing System • Combination Fixing System • Welded Pin Fixing System

Fire Protection

6.1

Technical specification

Rocksilk FireTech Slab, ...…mm thick, to be used to provide fire protection to structural steelwork. It is to be installed using the dry fix noggin system*/adhesive noggin fixing system*/ combination fixing system*/welded pin fixing system* (*specifier’s choice) as detailed in the Installation section. Noggin of Rocksilk FireTech Slab or Rocksilk FireTech Dry Fix Noggin Slab

Pig Tail Screws

Alternatively, consult the National Building Specifications, Standard version clause/clauses… K11/885…………… Knauf Insulation specification clauses can be downloaded from knaufinsulation.co.uk/nbs

Rocksilk FireTech Slab

Performance Durability Rocksilk FireTech Slab is rot proof, does not sustain vermin and will not encourage the growth of fungi, mould or bacteria. Rocksilk FireTech Slab is odourless and non-hygroscopic.

6.1

Fire performance Rocksilk FireTech Slab is classified as non-combustible to BS 476: Part 4: 1970(1984), Class 1 surface spread of flame to BS 476: Part 7: 1997, and Class ‘0’ to the Building Regulations. Rocksilk FireTech Slab is designed to provide up to 4 hours fire protection to structural steelwork, thereby satisfying the Building Regulations and insurance demands for periods of fire resistance.

Rocksilk FireTech Slab is non-wicking when tested to BS 2972: 1989: Section 12. When exposed to 90% relative humidity and 20ºC, Rocksilk FireTech Slab absorbs less than 0.004% of moisture. For Hp/A tables please visit knaufinsulation.co.uk

Technical Advice and Support Centre 01744 766666

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6.1

Fire Protection

Fire protection Installation of Rocksilk FireTech Slab

Dry Fix Noggin System

Adhesive Noggin Fixing System

Up to 2 hours fire protection

Up to 2 hours fire protection

Attach web pieces to noggins with pig tail screws at 100mm centres.

100mm wide noggins of Rocksilk FireTech Dry Fix Noggin Slab friction fitted between the flanges.

100mm wide noggin of Rocksilk FireTech Slab glued into place using suitable adhesive

Attach web pieces to noggins with pig tail screws at 100mm centres.

Attach flange pieces to web pieces using pig tail screws positioned 25mm in from each end and at 150mm centres.

Attach flange pieces to web pieces using pig tail screws positioned 25mm in from each end and at 150mm centres.

Combination Fixing System

Welded Pin Fixing System

Up to 3 hours fire protection

Up to 4 hours fire protection

Attach the Rocksilk FireTech Slab web pieces by impaling over the welded pins and securing in place with 38mm spring steel washers.

Attach flange pieces to web pieces using pig tail screws at 150mm centres. Adhesive should be used at the joint between subsequent web pieces.

Attach the Rocksilk FireTech Slab web and flange pieces by impaling over the 3mm diameter welded mild steel pins and securing in place with 38mm spring steel washers. Adhesive should be used at the joint between subsequent web pieces.

Alternative installation methods The Dry Fix Noggin System Is a fast and efficient friction fit noggin system that does not require adhesive. It can give up to 2 hours fire protection to BS 476: Part 21. When installing 20, 25 and 30mm Rocksilk FireTech Slab, noggins should be cut from a 30mm Rocksilk FireTech Dry Fix Noggin Slab. When greater thicknesses of Rocksilk FireTech Slab are used, the noggins are cut from a corresponding thickness of Rocksilk FireTech Dry Fix Noggin Slab. The Adhesive Noggin Fixing System Can be used to provide up to 2 hours fire protection to all sizes of structural steelwork.

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The Combination Fixing System Can be used to provide up to 2 hours fire protection to all sizes of structural steelwork, and up to 3 hours fire protection to steelwork with section factors (Hp/A) of up to 133m-1 for columns and 143m-1 for beams. The Welded Pin Fixing System Can be used to provide up to 3 hours fire protection to all sizes of structural steelwork, and up to 4 hours fire protection to steelwork with section factors (Hp/A) of up to 172m-1 for columns and 184m-1 for beams. If section factors are above 260m-1 contact our Technical Advice and Support Centre.

Technical Advice and Support Centre 01744 766666

www.knaufinsulation.co.uk

The use of a dense rock mineral wool slab requires no special vee cuts, drilling or sub-frames, making it fast and easy to install. Rock mineral wool slabs can be easily cut using hand or power tools. Note: Rocksilk FireTech Dry Fix Noggin Slab has a density of 200 kg/m3.

Fire Protection

Greater than 500mm

Y

Greater than 500mm

Full depth

100mm

Solid noggin formed from one or more pieces of Rocksilk FireTech Slab

6.1

100mm

T-shaped noggin formed from two pieces of Rocksilk FireTech Slab joined at right angles using pig tail screws

X Insert noggins as described at 600mm centres and if practicable leave for 4 hours for adhesive to cure. Cut Rocksilk FireTech Slab to size as follows: Beams: flange pieces to dimension X, web pieces to dimension Y + t (t = thickness of board) Columns: flange pieces to dimension X, web pieces to dimension Y + 2t

Attach web pieces to noggins using pig tail screws at 100mm centres

Attach flange pieces to web pieces using pig tail screws positioned 25mm in from each end at 150mm centres.

6.1

Note: For flanges greater than 400mm use welded pin and spring steel washers to provide extra retention of the flange piece of insulation. The welded pins should be located along the centre line of the flange at 300mm centres.

Adhesive noggin fixing system Noggins are cut 100mm wide from 20mm thick Rocksilk FireTech Slab. They should be cut to a suitable length relative to the web size to give a tight compression fit. Noggins are glued top and bottom using a typical adhesive thickness of 0.5mm and friction fitted between the flanges at 600mm centres. The noggins should be installed in such a way that they are slightly 'proud' of the flange (by about 2mm) and such that they coincide with joints between the boards.

It is preferable to leave the noggins in position for 4 hours to allow the adhesive to cure. However, where this is impractical Rocksilk FireTech Slab can still be fitted before the adhesive cures since the noggins are essentially friction fitted. For web depths greater than 500mm, T-shaped or solid noggins should be used, formed from Rocksilk FireTech Slab, and screwed together using pig tail screws.

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6.1

Fire Protection

Fire protection Application details for beams

Partition abutment using a noggin fixing system

Pig tail screws at maximum 100mm centres Rocksilk FireTech noggin Rocksilk FireTech Slab

Direct edge fixing with pig tail screws at maximum 150mm centres Attach flange piece to web piece by impaling over welded pins and securing the board to board joint with pig tail screws at 150mm centres. Spring steel washers are used over the welded pins to retain the insulation, any excess pin length being trimmed off

C-Stud partition with standard U-Channel head track

Wall abutment using a noggin fixing system

Pigtail screws at maximum 100mm centres Masonry wall Rocksilk FireTech Slab

Direct edge fixing with pig tail screws at maximum 150mm centres

Attach flange piece to web piece by impaling over welded pins and securing the board to board joint with pig tail screws at 150mm centres. Spring steel washers are used over the welded pins to retain the insulation, any excess pin length being trimmed off

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Technical Advice and Support Centre 01744 766666

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Fire Protection

6.1

Adhesive detail The adhesive used for gluing Rocksilk FireTech Slabs should be a thixotropic paste type based on soluble solids of silicate and potassium mixed with clay or refractory mineral filler to an approximate ratio of 70:30 by weight. Steelwork should ideally be dry but the presence of condensation will merely prolong the cure time, not weaken the bond strength. Since only the top and bottom surface of each noggin is glued with a typical adhesive thickness of 0.5mm, excellent rates of usage are achievable.

Pig tail screws The spirally wound or pig tail screws are made from 16 gauge galvanised wire and are available from stockists. A specification is available on request from our Technical Advice and Support Centre. The screws should be installed flush at 150mm centres on board to board joints and 100mm centres over noggins, using either power or hand tools. There is no need to countersink the screw heads.

Note: Steelwork should be clean and free from grease prior to the application of adhesive. * For further details contact our Technical Advice and Support Centre.

Column with partition abutment Rocksilk FireTech Slab

Knauf Wallboard not fixed to this C-Stud

6.1

Direct edge fixing with pig tail screws at maximum 150mm centres

Column with wall lining abutment

Masonry wall

Knauf Wallboard not fixed to this C-Stud

Rocksilk FireTech Slab

Direct edge fixing with pig tail screws at maximum 150mm centres

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Fire Protection

Fire protection Mezzanine floors Rocksilk FireTech Slab REFURB

• • •

Simple, clean and quick to install Provides up to 3 hours fire resistance System covers section factors up to 310 Hp/A - (A/V)

Fp03

Rocksilk FireTech Slab • Non-combustible with a Euroclass A1 reaction to fire rating • Zero Ozone Depletion Potential (ODP) • Zero Global Warming Potential (GWP)

Rocksilk FireTech Slab

Product

Performance

Rocksilk FireTech Slab is a dense rock mineral wool slab specifically designed for the fire protection of structural steelwork.

Fire performance Rocksilk FireTech Slab is classified as non-combustible to BS 476: Part 4: 1970 (1984). Class 1 Surface Spread of Flame to BS 476: Part 7:1977, and Class ‘O’ to the Building Regulations. Rocksilk FireTech Slab is designed to provide up to 3 hours fire protection to the mezzanine floor column support system, thereby satisfying the current Building Regulations and insurance industry fire resistance performance standards.

Typical construction The exposed surface of a steel section is fully enclosed in Rocksilk FireTech Slab, using a metal clip, snap-lock system.

Installation The column case is pre-fabricated to suit the specific beam or column. It is lined with Rocksilk Firetech Slab which is pre-bonded to the steel skin. Note that no adhesive is applied to the joints between individual slabs. The column case is made of galvanized or PVC coated steel minimum 0.7mm thick. For columns, the casing is normally supplied in two pieces with the closing face fixed with snap-lock joints.

Performance Rocksilk FireTech Slab is rot proof, does not sustain vermin, will not encourage the growth of fungi, mould or bacteria and is odourless and non-hygroscopic.

Three-sided encasements are secured at 300mm centres to continuous galvanized steel angles, or the flange of the steel section, or to the wall or floor at 500mm nominal centres. Alternatively the casing may be secured using an integral lip on the casing.

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Fire Protection

Time - mins 60

90

120

180

Board Thickness (mm)

Hp/A

20

224

25

260

30

310

35

310

40

310

45

310

20

91

25

115

30

139

35

165

40

190

45

217

50

244

55

260

60

270

65

310

20

57

25

72

30

87

35

102

40

117

45

133

50

149

55

165

60

181

65

198

30

49

35

58

40

66

45

75

50

84

55

92

60

101

65

110

Technical specification

Rocksilk FireTech Slab….mm thick, to be used to provide fire protection to structural steelwork in a mezzanine floor system. Alternatively, consult the National Building Specifications, Standard version clause/clauses… K11/885………… Knauf Insulation specification clauses can be downloaded from knaufinsulation.co.uk/nbs

Technical Advice and Support Centre 01744 766666

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Table 1 - Mezzanine floors

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www.knaufinsulation.co.uk

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Fire Protection

Cavity barriers Cavity barrier design

Design considerations

Concealed cavities

Every building must be designed and constructed in such a way that in the event of an outbreak of fire within the building, the unseen spread of fire and smoke within concealed cavities in its structure and fabric is inhibited. The Building Regulations require cavity barriers to sub-divide voids if they extend beyond certain dimensions.

Fire and smoke spread in concealed spaces is particularly hazardous because fire can spread quickly throughout a building and remain undetected by the occupants of the building.

In addition cavity barriers are also required to be placed above fire resisting partitions. Both glass and rock mineral wool products are ideal to act as cavity barriers due to their inherent non-combustibility. In the case of fire stopping minor imperfections of fit between construction elements or components, it is acceptable to seal small gaps with unfaced glass or rock mineral wool products. However, for specific periods of fire resistance in small and large voids (as required by the Building Regulations) it is necessary to use specific products that have been tested and assessed to offer the required performance when installed in a specific way, if necessary, using specific fixing components.

Cavity barriers are used to sub divide cavities and so prevent smoke and flame from by-passing fire-resisting walls and partitions. The maximum distance between barriers must be appropriate to the location of each cavity. Also, due consideration must be given to the class of surface exposed within the cavity. Cavity barriers should achieve at least 30 minutes fire resistance, providing a minimum of 30 minutes integrity and 15 minutes insulation. Detailed requirements are complex. For full details about the position and spacing of cavity fire barriers refer to the relevant sections of the appropriate Building Regulations.

Small cavity barriers Small voids include the cavities in external walls and voids beneath raised access floors. Larger voids include the spaces between suspended ceilings and soffits or roofs. In cavities in external walls the resilient properties of glass mineral wool mean that it can be compression fitted, between the outer leaf and the inner leaf or frame. The noncombustible nature of glass mineral wool allows it to resist the effects of fire, enabling it to remain in place during the fire and effectively block the transfer of fire through the cavity.

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Large cavity barriers In England, Wales and Northern Ireland, all cavity barriers should be constructed to provide at least 30 minutes fire resistance and 15 minutes insulation. In Scotland large cavity barriers, which are defined as being greater than 1m x 1m in size, must provide the same.

Fixing systems Any product used for fire protection can only be considered to be offering a specific period of fire protection when it is installed in the manner specified in the appropriate fire test report. This includes the specification of all associated fixings and supporting frame work.

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Fire Protection

Photograph courtesy of Henley Building Systems

30 minutes fire resistance

1 hour fire resistance

Definitions

The following definitions are taken from Approved Document B (Fire safety) - Volume 2: Buildings other than dwellinghouses (2006) Cavity barrier A construction, other than smoke curtain, provided to close a concealed space against penetration of smoke or flame, or provided to restrict the movement of smoke or flame within such a space.

50mm cavity

50mm Rocksilk Smoke and Fire Barrier

50mm Rocksilk Smoke and Fire Barrier

Fire stop Seal provided to close an imperfection of fit or design tolerance between elements or components, to restrict the passage of fire or smoke. Any unfaced glass or rock mineral product can be used as a fire stop.

6.1

Suspended ceiling of 12.5mm plasterboard

Period of fire resistance (mins)

Knauf Insulation solution

0 mins

30 mins

60 mins

90 mins

120 mins

150 mins

180 mins

210 mins

240 mins

Small cavity barriers - to be deleted

Fp04

Large cavity barriers Product: Rocksilk Smoke and Fire Barrier See page: 286 Fp05

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Fire Protection

Fire protection Small cavity barriers Earthwool Cavity Barrier

• Meets Building Regulation requirements for fire, acoustics and party wall bypass applications

NEW BUILD

Fp04

• Simple, clean and quick to install • Colour coded for easy identification Earthwool Cavity Barrier • Non-combustible with a Euroclass A1 reaction to fire rating • A+ Generic BRE Green Guide rating • Zero Ozone Depletion Potential (ODP) • Zero Global Warming Potential (GWP)

Earthwool Cavity Barrier stapled through top flange to sheathing to fully fill the cavity

Brick outer leaf

Product Earthwool Cavity Barrier is manufactured from a continuous length of non-combustible glass mineral wool which is compressed within a resilient polythene sleeve incorporating two flanges designed for ease of fixing. The polythene sleeve is colour coded to suit a variety of cavity widths from 50mm to 100mm and eliminates the need for weather protection during installation. T he barriers are 1200mm long and can be used in both vertical and horizontal applications, and are available in two standard widths (100mm and 300mm). 100mm barriers are used for normal fire stopping and noise reduction applications. 300mm barriers are used where higher performance levels are specified and at party wall/external wall cavity junctions.

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Typical construction

Installation

Earthwool Cavity Barriers are engineered to prevent the spread of smoke and fire through walls, floors and cavities in timber frame, metal frame and masonry buildings.

In vertical applications, both flanges of the Earthwool Cavity Barrier should be fixed to the inner leaf.

They are also suitable for reducing flanking noise transmission in these concealed cavities. The use of the correct size of Earthwool Cavity Barrier is essential. Earthwool Cavity Barriers are designed to compress to a tight fit in cavities and in the event of fire breaking into the cavity, Earthwool Cavity Barriers do not rely on the polythene flanges to hold them in place, but on their compression between the inner and outer leaf. It is, therefore, essential to specify the Earthwool Cavity Barrier by reference to the actual constructed cavity width.

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In horizontal applications, the top flange of the polythene sleeve should be fixed to the inner leaf. All joints and intersections of Earthwool Cavity Barriers should be closely butted.

Fire Protection

Typical junction with party wall

6.1

Technical specification

Timber frame construction Earthwool Cavity Barrier 100mm*/300mm* wide, coloured yellow*/ blue*/white* to be friction fitted in the positions shown on the drawings. Earthwool Cavity Barrier to fully fill the depth of the cavity. Polythene flanges to be stapled to the timber*/sheathing board* to hold the cavity barrier in place.

Earthwool Timber Frame Party Wall Slab

All joints and intersections of Earthwool Cavity Barriers should be closely butted together.

300mm wide Earthwool Cavity Barrier - stapled to sheathing board either side of party wall

Alternatively, consult the National Building Specifications, Standard version clause/clauses… P10/420…………… Knauf Insulation specification clauses can be downloaded from knaufinsulation.co.uk/nbs

Earthwool FrameTherm

Masonry construction Earthwool Cavity Barrier 100mm*/ 300mm* wide, coloured yellow*/ blue*/white* to be friction fitted in the positions shown on the drawings.

Fire performance Earthwool Cavity Barriers are manufactured from glass mineral wool which has a Euroclass A1 rating when classified in accordance with BS EN 13501-1. Earthwool Cavity Barriers have been tested for fire resistance in accordance with BS 476: Part 8: 1972 and will provide 60 minutes stability, integrity and insulation. Acoustic performance

Earthwool Cavity Barrier to fully fill the depth of the cavity.

Table 2 - Colour coding Cavity width (mm)

Colour

50-65

yellow

66-80

blue

81-100

white

All joints and intersections of Earthwool Cavity Barriers should be closely butted together. Alternatively, consult the National Building Specifications, Standard version clause/clauses… P10/420……………

6.1

Performance

Knauf Insulation specification clauses can be downloaded from knaufinsulation.co.uk/nbs

Building Regulations require the use of a cavity closer to reduce flanking noise transmission along party wall cavities and external wall cavities in masonry and timber frame constructions. Earthwool Cavity Barriers meet the generic description for cavity closers and will therefore ensure compliance with Part E and Robust Details in timber frame and masonry wall constructions.

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Fire Protection

Fire protection Large cavity barrier Rocksilk Smoke and Fire Barrier REFURB

Fp05

• Simple, clean and quick to install • Provides both fire and acoustic performance



• Versatile, flexible and adaptable system



Rocksilk Smoke and Fire Barrier • Non-combustible with a Euroclass A1 reaction to fire rating • Zero Ozone Depletion Potential (ODP)

Metal angle fixed to soffit

Rocksilk Smoke and Fire Barrier

50mm airgap

• Zero Global Warming Potential (GWP)

Rocksilk Smoke and Fire Barrier fixed to 50mm timber spacer

Product

Typical construction

 ocksilk Smoke and Fire Barrier is made from R rock mineral wool and formed into a flexible mattress faced on one side with galvanised wire mesh stitched in position.

For half an hour fire resistance A single layer of 50mm Rocksilk Smoke and Fire Barrier, applied as a hanging curtain, supported continuously from above and both sides, using the fixings listed in the Table 3.

Rocksilk Smoke and Fire Barrier is also available foil faced on one or both sides. Rocksilk Smoke and Fire Barrier must be installed in accordance with the specifications detailed below and on the following pages. If these specifications are not strictly followed the installation cannot be deemed to offer any specific period of fire protection.

At the base Rocksilk Smoke and Fire Barrier is either lapped freely on to the back of a suspended ceiling or fixed to a partition head. Suitable for drops up to 7 metres.

Use foil faced Rocksilk Smoke and Fire Barrier when the ceiling void is used as an air plenum.

Installation See page 288 - 291 for installation details. See Table 3 for specification of fixings and supporting metalwork.

F ixing components: Angle: Mild steel - 50mm x 50mm x 2mm or 60mm x 40mm x 2mm Strip: Mild steel - 40mm x 2mm See Table 3 for suitable method of fixing angles and strips to substrate.

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For one hour fire resistance Two layers of 50mm Rocksilk Smoke and Fire Barrier, separated by a 50mm air space, applied as a hanging curtain with wire mesh to the outside, supported continuously from above and both sides, using the fixings listed in Table 3. At the base it is either lapped freely on to the back of a suspended ceiling, or fixed to a partition head.

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Fire Protection

6.1

Technical specification

Half hour cavity barrier A single layer of 50mm Rocksilk Smoke and Fire Barrier (*foil faced) to be installed in the positions marked on the drawings, and fixed in accordance with the manufacturer’s recommendations. All joints either tightly butted, overlapped, or with edges returned, and stitched in a continuous spiral loop with 1mm diameter galvanised lacing wire.

Metal angles fixed to soffit

(* delete as appropriate) 

One hour cavity barrier Two layers of 50mm Rocksilk Smoke and Fire Barrier (*foil faced), separated by a 50mm air space to be installed in the positions marked on the drawings, and fixed in accordance with the manufacturer’s recommendations. All joints either tightly butted, overlapped, or with edges returned, and stitched in a continuous spiral loop with 1mm diameter galvanised lacing wire.

Rocksilk Smoke and Fire Barrier

Rocksilk Smoke and Fire Barrier fixed to timber spacer

(* delete as appropriate) 

Alternatively, consult the National Building Specifications, Standard version clause/clauses… K10/545…………… Knauf Insulation specification clauses can be downloaded from knaufinsulation.co.uk/nbs

Performance

When subjected to full scale fire resistance tests to BS 476: Part 22: 1987, a system comprising one layer of 50mm Rocksilk Smoke and Fire Barrier, fixed by using the components and methods detailed on the following pages achieved 19 minutes insulation, and retained its integrity for 35 minutes, after which time the test was discontinued. 50mm Rocksilk Smoke and Fire Barrier thereby satisfies the criteria laid down in the Building Regulations for cavity barriers, by exceeding the minimum requirement of 15 minutes insulation and 30 minutes integrity .

When subjected to full scale fire resistance tests to BS 476: Part 22: 1987, a system comprising a double layer of 50mm Rocksilk Smoke and Fire Barrier, fixed by using the components and methods detailed on the following pages, achieved 61 minutes insulation, and retained its integrity for 66 minutes, after which time the test was discontinued.

6.1

Fire performance Rocksilk Smoke and Fire Barrier is made from rock mineral wool and is classified as noncombustible to BS 476: Part 4: 1970. Rocksilk Smoke and Fire Barrier has a Class 1 Surface Spread of Flame to BS 476: Part 7: 1997 and is Class ‘0’ to the Building Regulations.

A double layer of 50mm Rocksilk Smoke and Fire Barrier thereby satisfies the criteria laid down in the Building Regulations for one hour cavity barriers. These tests incorporated vertical and horizontal joints between barriers. Fire resistance is effective from either side of the barrier. When tested, the wire side was exposed to the furnace as this is the side most vulnerable to fire.

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Fire Protection

Fire protection Installation of half hour cavity barrier

80mm minimum

1. Metal angle fixed to purlin

2. Fixed to purlin

3. Fixed to rib of coffered slab

4. Fixed across coffered ceiling

5. Perimeter fixing with steel strip

6. Junction with ceiling

Installation The following information and illustrations outline typical details for the installation of large cavity barriers. In case of uncertainty, refer to Knauf Insulation. Metal deck with overdeck insulation If Rocksilk Smoke and Fire Barrier runs with the slope of the roof, a supporting steel angle should be fixed between purlins and the smoke and fire barrier clamped to this with steel strip (Figure 1). The insulation should project 80mm beyond the strip to ensure a good seal. If fitted across the sheeting profile, Rocksilk Smoke and Fire Barrier should be bolted to the purlins (Figure 2). It is returned at the top, to a length equivalent to 3 times the profile depth, to allow for cutting at troughs and pushing securely into profiles. Alternatively, proprietary profile fillers may be used.

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Concrete decks Rocksilk Smoke and Fire Barrier is clamped between the deck and steel angle secured by expanding bolts. If the deck is coffered it should usually be possible to locate the cavity barrier along one of the ribs (Figure 3). If fitted across the coffering it should be clamped by steel strip, to the steel angle which is secured to the ribs. If the depth of coffering is less than 100mm, Rocksilk Smoke and Fire Barrier should be returned at the top by 300mm, to allow for cutting at the ribs and pushed securely into the coffering (Figure 4). If the depth of coffering is greater than 100mm, Rocksilk Smoke and Fire Barrier should be fixed around the coffering using steel angle, as described above. Alternatively, proprietary profile fillers may be used. The perimeter of the barrier should be secured with steel strip (Figure 5).

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At the ceiling junction, Rocksilk Smoke and Fire Barrier is cut and draped on and between the joists, and secured by fixing to steel angle, which is itself fixed to the joists (Figure 6). For suspended ceilings, see Figure 11. At partitions or wall heads, if a secure fixing is available, as at soffits, Rocksilk Smoke and Fire Barrier should be clamped with a steel strip Two layers of 50mm Rocksilk Smoke and Fire Barrier with a 50mm air space between them are needed for one hour fire resistance. In general two separate layers should be installed back to back, each in a manner identical to that shown for half hour fire resistance. The joints in the two layers should be staggered and Rocksilk Smoke and Fire Barrier returned outward at the top and bottom. The wire reinforced sides should be placed outward, see Figure 7.

6.1

Fire Protection

Fire protection Installation of one hour cavity barrier

7. Fixed to concrete slab

9. Fixing to timber spacer

8. Fixing to wall head

10. Fixing at perimeter

Fixing system specifications

Perimeter fixing Rocksilk Smoke and Fire Barrier should be secured with steel strip to the sides of the perimeter wall, so as to maintain the 50mm air space (Figure 10).

Table 3 - Specification of angles and strips Angle: Mild steel - 50mm x 50mm x 2mm or 60mm x 40mm x 2mm Strip: Mild steel - 40mm x 2mm

6.1

Partitions and wall heads If possible, Rocksilk Smoke and Fire Barrier should be secured with steel strip to the partition or wall head so as to maintain the 50mm air space (Figure 8). If this is not possible, it should be draped with a return of at least 150mm, or fixed to a timber spacer which is fixed to the partition or wall head (Figures 6 and 9).

Angle fixings to concrete decks and steel sections: angles 50 x 50 x 2mm Fire resistance

Maximum spacing of fixings (m) for the following drop heights (m)

period (mins)

3

3.5

4

4.5

5

5.5

6

6.5

30

2

2

2

2

2

2

2

2

2

60

2

2

1.75

1.5

1.5

1

1

0.75

0.75

M8 bolts

M6 bolts

Key:

7

Angle fixings to timber beams and trusses: angles 50 x 50 x 2mm Fire resistance

Maximum spacing of fixings (m) for the following drop heights (m)

period (mins)

3

3.5

4

4.5

5

5.5

6

6.5

7

30

2

2

2

2

2

2

2

2

2

60 Key:

2 2 1.75 1.5 1.5 1 1 0.75 Buildex HT screws, minimum 25mm thread penetration into timber

0.75

Buildex HT screws, minimum 40mm thread penetration into timber Steel strip fixings:

To masonry and concrete To timber To steel angle

Buildex Tapcon 4H masonry anchors Buildex HT range of fixings Steel bolts

Minimum return of Rocksilk Smoke and Fire Barrier - When clamped to flat surface (vertical or horizontal) 80mm. When loose laid over horizontal surface - 150mm.

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Fire Protection

Fire protection Jointing Rocksilk Smoke and Fire barrier

11. Junction with suspended ceiling

12. Vertical butt joint

13. Vertical returned joint

14. Vertical lap joint

500mm minimum overlap

15. Perpendicular joint

16. Horizontal joint at a drop

Suspended ceilings With suspended ceilings where positive fixing to wall heads or partition heads is not possible, the weight of Rocksilk Smoke and Fire Barrier and the stiffness of wire facing are such that it will form an effective seal if it laps the horizontal surface by a minimum of 150mm. Lapped joints are only permissible where the suspended ceiling has the same fire resistance as the cavity barrier. Rocksilk Smoke and Fire Barrier must be slit and fitted around any crossing tees to eliminate gaps and ensure that excessive loads are not transferred to the ceiling (Figure 11). Jointing This section describes the approved methods for joining adjacent pieces of Rocksilk Smoke and Fire Barrier. The methods are applicable to both half and one hour large cavity barriers.

290

Vertical and horizontal joints Three methods of securing the joints between adjacent pieces of Rocksilk Smoke and Fire Barrier are approved. Joints are tightly butted together and stitched in a continuous spiral loop with 1mm diameter galvanised lacing wire. The stitching should pass through the reinforcement mesh and the wool on each side of the butt joint at centres not exceeding 100mm (Figure 12). Alternatively the Rocksilk Smoke and Fire Barrier edges are returned at least 80mm and wired together (Figure 13), or they may be lapped at least 100mm and wired together (Figure 14). Perpendicular joints The junction between two barriers should be securely wired together (Figure 15) with a return of at least 80mm.

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Drops All barriers can be used for drop heights up to 5m without additional support. For drops between 5m and 7m it is necessary to introduce additional supporting members in order to support the weight of the fire barriers (Figure 16). Services Services which are permitted by Building Regulations to penetrate barriers, should be provided with collars of Rocksilk Smoke and Fire Barrier at least 300mm long, sewn to the main barrier and then strapped or wired so as to avoid any possibility of gaps (Figure 17). A half hour barrier requires a collar on one side of the barrier. A one hour barrier requires one collar on both sides of the barrier system.

Fire Protection

6.1

Fire protection Penetrating pipes and ducts

300mm minimum 17. Penetrating pipe

18. Penetrating steelwork

Penetrating steelwork This should be provided with a collar of Rocksilk Smoke and Fire Barrier at least 300mm long (Figure 18). The collar is fixed to the concrete or metal deck by clamping against these surfaces behind steel angle. The voids in the steelwork are filled with Rocksilk Smoke and Fire Barrier (figure 18). A half hour barrier requires a collar on one side of the barrier. A one hour barrier requires one collar on both of the layers of the barrier system. Access Where permanent access is needed through the barrier, a fire door and frame, rated to the appropriate fire resistance, must be used. Rocksilk Smoke and Fire Barrier should be fixed securely to the frame.

Handling Depending on the size of the barrier and the working space available, it is sometimes difficult to hold the material in place while top fixings are being secured. It will be found helpful to make a temporary prop from, e.g. slotted angle. This may comprise a crosspiece of length appropriate to the width of the Rocksilk Smoke and Fire Barrier, with studs on the top which will hook into the wire mesh of the Rocksilk Smoke and Fire Barrier. This may be swivelled on the top of a handle, and secured horizontally or to the angle of the roof by an adjustable brace. It is used to hold the Rocksilk Smoke and Fire Barrier up, 100mm or so behind the fixing location, while fixing is being carried out. When fixing to a sloping deck, the top of the Rocksilk Smoke and Fire Barrier should be trimmed to the correct angle to ensure that joints are truly vertical (Figure 19).

Following trades The integrity of barriers must be restored if disturbed by following trades, either during the building process or after completion. This instruction should be incorporated into the building handbook.

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6.1

19. Temporary framework to ease handling

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Fire Protection

Internal floor Refurbishment of timber separating/internal floor Earthwool Flexible Slab REFURB

• Existing ceiling can be retained, avoiding disruption to rooms below

Fp06

• Provides thermal and acoustic insulation as well as fire resistance  Meets the requirements of • Approved Document E for sound resistance of internal floors Earthwool Flexible Slab • Non-combustible with a Euroclass A1 reaction to fire rating • A+ Generic BRE Green Guide rating • Zero Ozone Depletion Potential (ODP) • Zero Global Warming Potential (GWP) Support mesh stapled to joists Existing ceiling Earthwool Flexible Slab

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Minimum 18mm Chipboard

Products

Typical construction

Installation

E arthwool Flexible Slab is a multi-purpose rock mineral wool slab designed to be friction fitted in a wide range of acoustic, thermal and fire resistant applications.

The use of Earthwool Flexible Slab in a suspended timber floor achieves one hour fire resistance, whilst allowing the existing ceiling to be retained.

Introduction

To achieve one hours fire resistance:

After removal of the floor deck, line the voids in the floor with 25mm wire mesh, to form a support tray for the insulation. Staple the wire mesh to the sides of the joists, at least 40mm up from ceiling level.

Where the loft space of a two storey house is converted into habitable accommodation, the floor to the new rooms must have 30 minutes fire resistance over any part of the escape route directly below. This is often the case when, for example, the floor of the new room extends over a landing in the stairway enclosure below. The solution on this page provides the required period of fire protection without having to upgrade the existing ceiling.

• The floor deck should be at least 18mm thick tongued and grooved chipboard or timber boarding • The joists must be at least 200mm deep and 37mm wide • The wire mesh should be stapled to the sides of the joists at least 40mm above the ceiling level • Any ceiling can be used

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Cut 100mm Earthwool Flexible Slabs to size and lay onto the wire mesh support, so that there are no gaps between the insulation and the joists. Butt joint the insulation slabs so there are no gaps between them. Fix a chipboard floor deck, at least 18mm thick, over the entire floor area.

Fire Protection

Typical wall floor junction

Typical specification

Lay 100mm Earthwool Flexible Slab on 25mm chicken wire mesh, stapled to sides of joists at least 40mm up from ceiling level and at 600mm centres. The joists should be at least 200 x 37mm and spaced at not more than 600mm centres. The flooring board to be at least 18mm thick.

Existing wall

Earthwool Flexible Slab cut and friction fitted between last joist and wall

6.1

Minimum 18mm chipboard

Alternatively, consult the National Building Specifications, Standard version clause/clauses… P10/250…………… Knauf Insulation specification clauses can be downloaded from knaufinsulation.co.uk/nbs

Earthwool Flexible Slab

Wire mesh stapled to joists to provide support for Earthwool Flexible Slab

Existing ceiling

Performance

6.1

Fire performance Earthwool Flexible Slab is classified as Euroclass A1 to BS EN 13501-1 and noncombustible to BS 476: Part 4: 1970 (1984), Class 1 Surface Spread of Flame to BS 476: Part 7: 1997 and Class ‘0’ to the Building Regulations. Acoustic The acoustic performance of an internal floor containing 100mm of Earthwool Flexible Slab (and 12.50mm standard plasterboard ceiling) will be at least 40dB and therefore, meet the requirements of Approved Document E of the Building Regulations.

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Fire Protection

Fire protection Steel Duct Encasement Rocksilk Pyroduct Slab NEW BUILD

Fp07

• Lightweight, mineral wool has approximately one half to one third of the weight of traditional silicate and vermiculite boards • Fast and simple fixing system makes the slabs quick and easy to install • Provides excellent acoustic and thermal performance insulation

REFURB

Blockwork compartment wall

Rocksilk Pyroduct Slab • Non-combustible with a Euroclass A1 reaction to fire rating



• Zero Ozone Depletion Potential (ODP) • Zero Global Warming Potential (GWP) RS33 Slab as packing Steel angle rivetted at 150mm centres Rocksilk Pyroduct fixed to duct Rocksilk Pyroduct glued to wall and insulation

Product Rocksilk PyroDuct Slab is a 160 kg/m3 density rock mineral wool slab. The slabs are faced with a bright Class ‘O’ reinforced aluminium foil, making it suitable for applications above clean rooms, within air plenums or for aesthetic purposes.

Typical construction The exposed surfaces of steel ductwork are fully enclosed in Rocksilk PyroDuct Slab using the fixing system shown on the following pages. Rocksilk PyroDuct Slab can be used to provide up to 2 hours fire protection to steel ductwork.

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Installation

Performance

Rocksilk PyroDuct Slab is applied in a single thickness, removing the need for multi layer applications. This provides assurance of a uniform thickness and therefore the integrity of the system and allows for easy verification of correct installation on site.

Fire Rocksilk PyroDuct Slab is classified as non-combustible to BS 476: Part 4: 1970 (1984), Class 1 surface spread of flame to BS 476: Part 7:1997 and Class ‘O’ to the Building Regulations.

Individual slabs are 1200mm long and 600mm wide making them easy to carry around site. Their lightweight nature also makes them easy to use.The fixing system of welded pins and square edge butt joints gives a fast and simple system which requires no special vee cuts, drilling or sub-frames and also makes the slabs fast and easy to install.

Rocksilk PyroDuct Slab has been tested in accordance with BS 476: 24:1987 and can provide up to two hours fire resistance for steel ductwork exposed to fire either inside or outside of the duct.

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Moisture resistance Rocksilk PyroDuct Slab is non-wicking when tested to BS 2972: 1989: Section 12. When exposed to 90% relative humidity and 20ºC, Rocksilk PyroDuct Slab absorbs less than 0.004% of moisture.

Fire Protection

6.1

Typical specification

Rocksilk PyroDuct Slab...........mm thick to be used to provide up to 2 hours fire protection to steel ductwork as detailed in this schedule (specifier to state which ducts require fire protection). It is to be installed using the fixing system as detailed, and at a thickness with due regard to the duct size, orientation and period of fire protection required.

Foil facing omitted for clarity

Table 4 - Required thickness of Rocksilk PyroDuct Slab

Weight

Period of fire resistance (hours)

Vertical ducts

Horizontal ducts

Kitchen extract ducts

0.5

-

-

45

1.0

45

45

90

2.0

90

90

-

Table 5 - Weight of slabs Thickness (mm)

Weight (kg/m2)

45

7.20

90

14.40

Table 5 shows the weight per square metre of Rocksilk PyroDuct Slab.

Fire protection Any vertical or horizontal, rectangular or square steel ductwork associated with ventilation and/or air conditioning systems, including ducted supply and extract systems (whether through ducts or plenums), mechanically assisted systems and those relying on natural convection can be protected with Rocksilk PyroDuct Slabs to provide the required degree of fire protection.

6.1

Thickness of insulation (mm)

Achieving the required fire performance The required thickness of Rocksilk PyroDuct Slab depends upon the orientation of the duct and the period of fire resistance required. Table 4 displays the thicknesses required for vertical and horizontal ducts and also for kitchen extract ducts for the commonest periods of fire resistance.

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Fire Protection

Fire protection

m

0m

35

mm

0 35

Steel Duct Encasement

35

0m

m

Greater than 1000mm

Greater than 1000mm 35

50mm

500mm max

500mm max

1. Weld 3mm diameter steel pins at 350mm longitudinal centres along the centre line of the vertical sides of the ductwork.

X

Y exceed 1000mm, 2. Where the dimension of the vertical sides the steel pins should be in rows starting 50mm in from the edge and spaced apart at a maximum of 500mm centres.

Greater than 1000mm 0m

35

50mm

m

0m

35

50mm

m 0m

X

m

500mm max

Y

X 500mm max

500mm max m 0m

m

0m

35

50mm

Y 50mm

35

3. Weld 3mm diameter steel pins at 350mm longitudinal centres along the horizontal surfaces of the ductwork in rows starting 50mm in from the longitudinal edge and spaced apart at a maximum of 500mm centres.

4. Cut Rocksilk PyroDuct Slab to size as follows: horizontal surfaces to dimension X, vertical surfaces to dimension Y + 2t, where t = thickness of insulation.

500mm max m

0m

35

50mm

6

7 8

5. Attach the insulation by impaling over the welded pins and securing with 38mm spring steel washers.

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6. Glue all board to board joints using a thixotropic silicate based adhesive. 7. Trim off pin lengths to about 30mm excess and bend this excess to form a right angle with the insulation. 8. Although not essential, it is good practice to offset the joints for each surface.

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Fire Protection

6.1



Fire protection Steel Duct Encasement

Vertical ducts The installation detail on the previous pages for horizontal ducts is also relevant for vertical ductwork, though the horizontal and vertical surfaces referred to for horizontal ductwork will be the longest and shortest surfaces respectively in vertical ductwork.

Ductwork passing through compartment walls or floors In accordance with The Building Regulations, when ductwork passes through any element of construction which has a designated period of fire resistance, the integrity of that compartment should be maintained. In these situations, the ductwork in the immediate vicinity of the penetration should be stiffened as follows:

a) When the flange is within 100mm of the penetration then a 50 x 50 x 3mm steel angle should be rivetted to the top edge of the duct using a single row of rivets with washers starting 50mm from the edge and at 150mm centres. Earthwool Building Slab RS33 should be used to pack any gap between the main insulation and the blockwork.

6.1

120 x 90mm sections of Rocksilk Pyroduct Slab is glued to the wall and main Pyroduct insulation.

b) When the flange is greater than 100mm from the penetration, two angles should be used, fixed as described in a) above, and 45mm Rocksilk Pyroduct Slab installed perpendicular to the duct at the penetration.

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Knauf Insulation Ltd PO Box 10 Stafford Road St Helens Merseyside WA10 3NS

Customer Service (Sales) Tel: 0844 800 0135 Fax: 01744 612007 Email: [email protected] www.knaufinsulation.co.uk

Technical Advice and Support Centre Tel: 01744 766 666 Fax: 01744 766 667 Email: [email protected]

Literature Tel: 08700 668 660 Fax: 0870 400 5797 Email: [email protected]