Flamex XT - Fire Rated Elastomeric Joint Sealant

Product Overview

Flamex XT is a high-performance fire and acoustic rated elastomeric joint sealant based on Silyl Modified Polymers. It combines the weathering and adhesion performance of a silicone sealant with the toughness and stain-free properties of a polyurethane sealant. The product is supplied in 600ml sausages for convenient application via standard sausage guns.

Key Technical Specifications

Form and Properties

Flamex XT is formulated as a smooth, non-slump paste available in Concrete Grey color. The sealant exhibits exceptional performance characteristics across multiple technical parameters:

Property	Specification
Skinning Time	55 minutes @ 23°C / 50% RH
Tooling Time	30 minutes @ 23°C / 50% RH
Cure Time	>2mm / 24 hours @ 25°C / 50% RH
Hardness	31 Shore A
Joint Movement Capability	Total 40% (+/- 20%)
Elongation at Break	260%
Modulus @ 100% Elongation	0.67 MPa (ASTM D412)
Specific Gravity	1.47
VOC Content	13g / litre
Acoustic Rating	Up to 50Rw(CT;CTR)

Fire and Acoustic Performance

Fire Resistance Rating

Flamex XT achieves outstanding fire resistance performance based on AS1530.4:2014 testing standards. The following table summarizes fire performance across different joint configurations:

Joint Size (Width x Depth)	Configuration	Integrity (min)	Insulation (min)	FRL
20mm x 10mm	Sealed both sides	243*	243*	-240/240
20mm x 10mm	Sealed non-fire side only	243*	151	-/240/150
20mm x 20mm	Sealed non-fire side only	243*	202	-/240/180
30mm x 15mm	Sealed non-fire side only	243*	150	-/240/150

\ denotes "no failure" at 243 minutes, at which time testing was terminated*

The testing was conducted in joints between concrete wall panels 180mm thick, demonstrating the sealant's capacity to maintain integrity for up to 4 hours of fire exposure.

Acoustic Performance

Flamex XT provides acoustic sealing with a rating of up to 50Rw(CT;CTR), making it suitable for sound insulation applications in building construction.

Performance Advantages

Flamex XT delivers multiple performance benefits for demanding applications:

• Fire Rated for up to 4 hours duration
• Meets BCA Requirements for fire and acoustic sealing applications
• 40% Joint Movement Capability accommodates significant structural movement
• Outstanding Weathering and UV Resistance maintains color and integrity in external applications
• Excellent Primerless Adhesion to concrete, timber, masonry, aluminium, metals, and ceramics
• Will Not Stain masonry or other surfaces during application or curing
• Blister Free Cure in high humidity or on damp surfaces
• Low Odour with very low VOC of 13g/L
• Isocyanate Free composition for improved safety and environmental performance
• Halogen Free formulation meeting safety standards

Application Specifications

Suitable Substrates

Flamex XT provides primerless adhesion to a wide range of building materials without requiring primers:

• Concrete
• Timber
• Masonry
• Plasterboard
• Fibre cement
• Metals (aluminium, steel)
• Ceramics
• Brickwork
• AAC (Autoclaved Aerated Concrete)
• Most coating surfaces

Typical Applications

Flamex XT is designed for use in:

• Fire rated joints in control joints of concrete, masonry, AAC, and brick construction
• Acoustic sealing between common building materials
• External and internal non-trafficable control joints
• High performance applications in building facades and general construction
• Fire and acoustic rated construction requiring up to 4 hours fire resistance

Design Criteria

For fire-rated applications, Flamex XT should be applied in joints:

• Width Range: Between 20mm and 40mm
• Minimum Depth: 10mm or half the width for joints wider than 20mm
• Backing Rod: Install backing rod in joint to control sealant depth and prevent back-of-joint contact

Limitations

• Not suitable for permanent immersion or below water line use
• Do not apply to wet surfaces to ensure proper adhesion and cure
• Designed for non-trafficable applications only

Surface Preparation Requirements

Proper surface preparation is essential for optimal performance:

• Joint surfaces must be clean, dry, and free from frost
• Remove all dirt, laitance, loose materials, and foreign matter
• Remove all rust, scale, and protective lacquers from metal surfaces
• Non-porous surfaces should be degreased using Fosroc Solvent 10
• Install a bond breaker to prevent sealant contact with the back of the joint
• Use self-adhesive polyethylene tape for shallow joints or Expandafoam Backing Rod for deep joints

Application and Tooling

Gun Application

• Flamex XT is applied using a suitable sausage gun
• Insert the 600ml sausage into the gun
• Cut a slit at the top of the sausage
• Replace the end cap and nozzle before application

Extrusion and Tooling

• Extrude the sealant firmly into the joint to ensure complete contact with joint faces
• Easy tooling to a smooth finish without soapy water or tooling aids
• If tooling aids are required, apply only after initial tooling into the joint to prevent joint face contamination

Cleaning

• Clean tools immediately after use with an alcohol-based solvent

Paintability and Finishing

Flamex XT is paintable with water-based and solvent-based paints:

• Water-based paints: Can be applied typically after a thick skin develops, ideally within 7 days of sealant application
• Solvent-based paints: Require priming with water-based paint before application
• Flexible coatings: Applied coatings must accommodate expected joint movement

Supply and Coverage

Packaging

• Form: 600ml sausages supplied in cartons of 12
• Product Code (Concrete Grey): FC920045-600ML

Coverage

One 600ml sausage will supply approximately 3 metres of 20mm x 10mm sealant bead.

Storage and Shelf Life

• Shelf Life: 12 months when kept in original, unopened packaging
• Storage Conditions: Dry conditions between +10°C and 25°C with 55% relative humidity
• Storage Location: Away from direct sunlight and moisture

Standards Compliance

Flamex XT complies with the following standards:

• AS1530.4-2014: Fire test in vertical concrete control joints
• AS1530.3-1999: Methods for Fire Test on Building Materials

Fire Safety Indices (AS1530.3-1999)

Parameter	Value
Ignitability Indices	16
Spread of Flame Index	0
Heat Evolved Index	1
Smoke Developed Index	0-1

Test reports are available on the Fosroc website.

Chemical and Environmental Properties

• Composition: Based on Silyl Modified Polymers (SMP)
• Isocyanate Free: No isocyanate compounds in formulation
• Halogen Free: Safe formulation meeting environmental standards
• VOC Content: Very low at 13g per litre
• Odour: Low odour formulation

Manufacturer and Distribution

Flamex XT is manufactured and sold under license from Fosroc International Limited. Fosroc, Flamex, and the Fosroc logo are trademarks of Fosroc International Limited, used under license. In Australia and New Zealand, the product is distributed by Parchem Construction Supplies Pty Ltd, operating with ABN 80 069 961 968 at 1956 Dandenong Road, Clayton, Victoria 3168. Technical support is available at 1800 812 864 and www.fosroc.com.au.

Safety Documentation

A comprehensive Safety Data Sheet (SDS) is available from the Fosroc website and should be read carefully prior to use, as application or performance data may change over time. In emergencies, contact any Poisons Information Centre (phone 13 11 26 within Australia) or a doctor for advice.

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References

• [1] Fosroc_Flamex_XT_TDS.pdf
• [2] Fosroc_Flamex_One_TDS.pdf