Vermitex^® '7C' & 'AF'

Roof Ceiling
(Interior applications)

Product Description

Vermitex^® ‘7C’ and ‘AF’ are Cement and Gypsum based, respectively, cementitious proprietary blends which have been tested for application to Roof Ceiling elements requiring passive fire protection upgrade. Chopped Fibreglass strands are added to the Vermitex^® ‘7C’. These products do not contain asbestos. Application may be carried out by mechanical means to interior or exterior roof ceiling structures with the aid of mechanical reinforcement (1).

Recommended Uses

Vermitex^® ‘7C’ and ‘AF’ may be applied to a multitude of backgrounds to enhance the Fire Resistance Level (FRL) of building and construction elements. This Data Sheet addresses application to Interior and Exterior Roof Ceiling elements.

The Vermitex^® ‘7C’ and ‘AF’ Roof Ceiling system may be employed to achieve a Fire Resistance Level from 1 hour to 4 hours replacing much heavier and expensive systems.

The system offers the following benefits:

• Economical pricing as well as reduced Construction time.

• Materials for the Roof Ceiling System may be craned onto the required floor together with the roofing materials. The installation of the ceiling (channels & meshing) can commence as soon as the purlins have been installed. Areas can be sprayed as soon as the roof sheeting is installed.

• The Vermitex^® ‘7C’ and ‘AF’ Roof Ceiling System is highly cost effective and most practical when a FRL has to be achieved where a ceiling void contains services such as air conditioning ductwork, stormwater pipes etc.

• In normal circumstances these would require costly Fire Dampers and/or Fire Collars at the intersection with the Fire Rated Roof Ceiling. To avoid such costly items, the Vermitex^® ‘7C’ and ‘AF’ Roof Ceiling system may be installed directly to the underside of the roof purlins followed by a more conventional decorative ceiling below. This technique allows for the unencumbered installation of services throughout the void without costly Fire Isolating devices (eg Fire Dampers, Fire Collars etc).

• Structural steel members may be incorporated within the ceiling membrane without restrictive (minimum) clearances from the bottom flange of said members.

• In certain circumstances the Vermitex^® ‘7C’ and ‘AF’ Roof Ceiling System may also include Fire Dampers. (2)

• The one hour Vermitex^® ‘7C’ and ‘AF’ Roof Ceiling System (Incipient Spread of Fire included) is very light and at only 35 mm thick is also very thin.

• The Vermitex^® ‘7C’ and ‘AF’ Roof Ceiling System also has inherent noise abatement properties across the entire frequency spectrum (2).

Application of the Vermitex^® ‘AF’ may be carried out by hand but preferably by mechanical means to suitable reinforcing substrates such as expanded metal lath, ripple iron, riblath etc. This Data Sheet addresses application to Roof Ceiling elements.

Product Characteristics

Tested Properties

Application Instructions

Vermitex^® ‘7C’ and ‘AF’ material components of the Roof Ceiling system are mill-mixed compounds that can be sprayed onto substrates requiring protection at the corresponding thickness stipulated by the Manufacturer (refer Thickness Tables over). The Roof Ceiling should be free from: battens, services (ducts & pipes where possible), light fittings, brackets or any other components that prevent the proper installation of the Roof Ceiling system to the background. Mechanical reinforcement is required for interpolated thickness specified in the thickness tables.

Vermitex^® ‘7C’ and ‘AF’ materials, when applied in ventilated areas, to a thickness of 25 mm, will dry in 2 weeks. Please note that Vermitex^® ‘7C’ and ‘AF’ are prone to frost damage and temperatures surrounding the areas being sprayed should not be allowed to fall below 4°C for a week, after installation. They may be applied to a thickness of 20 mm in one application, thicker applications are possible, however this will depend on the state of the background being sprayed, its water-uptake capacity and the experience of the applicator. Multiple coatings will achieve a smooth and even textured finish, however a new coating should only be applied over one that has partially set. Where this is not possible the last coating surface should be left with a ‘deep & rough texture’ or purposefully scratched. When ‘Trowelling’ or ‘Ruling’ is unavoidable the applicator should not ‘overwork’ or ‘polish’ the surface as well as not apply too much pressure in order to avoid dislodgement of the material from the mesh.

In the case of Roof Ceiling the purlins must be designed (size & span) to carry the appropriate loads. Any partitions allowed to abut to the underside of the Roof Ceiling, must have a FRL equal to the Roof Ceiling system. If partitions are not ‘rated’ the Fire Vermitex^® ‘7C’ and ‘AF’ Roof Ceiling system should be allowed an uninterrupted cover throughout the area, to avoid integrity failures.

Penetrations through Roof Ceilings require attention to ensure the Insulation Criteria is not compromised, such as in the case of metallic pipes, ducts fire dampers etc. Some Building Codes and/or Standards specifically require appropriate tolerances and details to ensure the Insulation criteria is not compromised in these circumstances.

In old building’s refurbishment, roofs may have existing ceilings in place. These are costly to remove, may create health issues with their disposal and slow down the construction program. When existing ceilings are to be left in place the Vermitex^® ‘7C’ and ‘AF’ Roof Ceiling system, must be supported from the main ‘runner’ supports rather than the Ceiling ‘furring’ channels/battens. In more cases than not, this may require the installation of mechanical reinforcement in combination with furring channels.

Where light fittings are required they should be recessed with the whole enclosure fire rated or the light fitting surface mounted. In both cases the electrical wiring should penetrate the mesh, travel 100 mm along the mesh, then be allowed to drop down from the mesh. Suitable electrical ties should be used (CAUTION: DO NOT USE TIE WIRE!).

Vermitex^® ‘7C’ and ‘AF’ may be painted however suitable sealers and paints are required. (2)

Bond Coat, Primer Compatibility and Corrosion prevention

When applying Vermitex^® ‘7C’ and ‘AF’ to mechanical reinforcement, a ‘Bond Coat’ is not required. However when Vermitex^® ‘7C’ and ‘AF’ are sprayed to Ripple Iron or any smooth sheet metal backing a ‘Bond Coat’ equal to Vermitex^® ‘7’ must be applied. No specific thickness is required when spraying Vermitex^® ‘7’, and coverage of between 50% and 75% of the area is required. Vermitex^® ‘7’ will enhance the adhesion of the Vermitex^® ‘7C’ and ‘AF’ to the substrate as well as facilitate application of the spray materials by reducing ‘slippage’ on smooth vertical backgrounds.

In certain applications, Vermitex^® ‘7C’ and ‘AF’ may be applied directly onto the bare steel without the need for a steel primer (Refer to LAF for further detailed advice). If a concern exists about moisture levels, the substrate should be suitably primed with an approved rust preventative primer. Where primers are required alkali resistant zinc-rich primers are recommended, however the paint manufacturer should be consulted to ensure compatibility with the Vermitex^® ‘7C’ and ‘AF’ (2).

Chemicals which have an impact on cement and plaster will also have an impact on Vermitex^® ‘7C’ and ‘AF’, in these circumstances the Vermitex^® ‘7C’ and ‘AF’ must be top-coated with suitable sealers and paints for protection (Refer to LAF for more details).

Vermitex^® ‘7’ & ‘7C’ may react with Aluminium and Aluminium alloys and a suitable primer is recommended.

Steel members and separating construction

When steel elements intersect or form part of a Roof Ceiling element (partition, ceiling, etc) care must be taken to ensure that the Insulation Criteria requirement (mandatory in some Building Codes & Standards) for the Roof Ceiling element is not impeded.

Coverage

One 50 litre bag of Vermitex^® ‘7C’ and ‘AF’ will cover approximately 1m² at a nominal thickness of 50 mm (without wastage considerations).

Vermitex^® Specification (Broad Form)

Mechanical reinforcement equal to Expanded Metal Lath, Ripple Iron or Rib Lath, shall have been installed in accordance with the Manufacturers instructions and any relevant Code and Standards.

Prior to Vermitex^® ‘7C’ and ‘AF’ application commencing, the substrate shall be inspected by the Main Contractor to ensure all elements to be sprayed are free from any substances which impair proper adhesion of the spray material. (2)

All adjacent areas not requiring treatment shall be suitably protected against droppings and overspray.

Vermitex^® ‘7C’ and ‘AF’ as manufactured by L & A Fazzini Manufacturing Pty Ltd shall be installed by an approved Specialist Contractor to the thickness of ..xx.. mm to provide a Fire Resistance Level of ..aaa / bbb / ccc ..(insert required thickness and FRL).. .

The Specialist Contractor shall provide all materials, accessories, spray equipment, tools, inspection services and labour to satisfactorily carry out the works in best trade practice. All workmanship and installation techniques shall comply with the Manufacturers ‘Application Instructions’, relevant Building Code Statutory requirements and applicable ASTM, BS or AS Standards.

Refer to Test Data for more information

Vermitex^® ‘7C’ and ‘AF’ Thickness Table

Tested to AS 1530.4

FRL	Vermitex® ‘7C’ and ‘AF’ Thickness (mm)
	Standard	Incipient	Layers of Mesh
60/60/60	25	25	1
90/90/90	25	30	1
120/120/120	32	40	1
180/180/180	50	63	2
240/240/240	60	86	2

N.B. - Highlighted Grey cell denotes 2 layers of Mechanical Reinforcement is required alternatively Trimesh^® may be used.

Vermitex^® ‘AF’ Thickness Table

Assessment for refurbishment of Floor Ceiling system

Health Statement

Foamed Vermitex^® ‘AF’ contains no asbestos and presents no known health hazard before, during or after application. Normal precautions relevant to the handling of gypsum products apply: dust mask, eye protection and covering of sensitive skin.

NOTES:
1. Refer to LAF for reinforcement, stabilization and other system requirement details as well as other Foamed Vermitex^® ‘AF’ applications
2. Refer to LAF for further detailed information
3. Refer to the Heritage Council of NSW or LAF for further information

For more information or MSDS on Vermitex^® ‘7C' and ‘AF’ or any other products,

please see the technical data page, or contact: L & A Fazzini Manufacturing Pty Ltd

Email:sales@lafgroup.com