Vermitex^® 'AF' & 'DX'

Steel Decking
(Interior & Exterior applications)

Product Description

Vermitex^® ‘DX’ and ‘AF’ are Cement and Gypsum based cemetitious proprietary blends that have been tested for application to proprietary and common steel decking elements requiring passive fire protection upgrade.

Recommended Uses

Structural Decking systems have been commonly employed to reduce site costs, and construction time (Jump Start). The majority of structural decking systems are supported by structural steel members, hence the requirement for some form of Fire Protection. A ‘Fire Mesh’, introduced into the concrete topping, is a common way of avoiding the need for sprayed Fire Protection. However in some cases: change of building use, load changes etc. fire mesh cannot be introduced and therefore a Vermitex^® ‘DX’ and ‘AF’ sprayed fire protection can offer a cost effective solution.

Vermitex^® ‘DX’ and ‘AF’ can be used on most types of Proprietary Decking Systems, the more common ones being: Bondek, Condek and the older Celdek type. Vermitex^® 'AF' can also be re-sprayed to decks which have had Asbestos or Asbestos contaminated compounds removed.

As with all construction elements, in particular their behaviour under fire, it is imperative that the concrete cover above the decking be the same as the concrete cover employed in the tested prototype. Where a deficiency in material thickness is found to exist, precautions must be taken to ensure that the concrete cover is increased to comply with fire load requirement. If this is not possible, Vermitex^® ‘DX’ and ‘AF’ may be applied below the decking to achieve the required FRL.

With the older types of Decking systems (Celdek, Bondek), the designer should ascertain if the floor system has an in-built ducted system (Header Ducts for distribution of electrical services) present. Where ‘Header Ducts’ are present the thickness of the Vermitex^® ‘DX’ and ‘AF’ will have to be increased.

Application should be by mechanical means to interior or exterior steel decks and other substrates generally without the aid of mechanical reinforcement(1). Vermitex^® ‘DX’ and ‘AF’ may also be applied to a multitude of backgrounds to enhance the Fire Resistance Level (FRL) of building and construction elements and at the same time provide a durable finish. This Data Sheet addresses application to both Interior as well as Exterior steel decking elements.

Product Characteristics

Tested Properties

Application Instructions

Vermitex^® ‘DX’ and ‘AF’ are mill-mixed compounds which can be sprayed onto substrates requiring protection at the corresponding thickness stipulated by the Manufacturer (refer Thickness Tables). The surface of the steel deck should be clean and free from: timber formwork, rust, rolling oils, excessive dust or any substance which might impair proper adhesion of the Vermitex^® ‘DX’ and ‘AF’ to the background.

Mechanical reinforcement is only required for interpolated thickness over 30 mm, however a ‘Primer/Bond-coat’ equal to Vermitex^® ‘7’ is mandatory. Notwithstanding the above and only in special cases such as: on continuous smooth surfaces, either horizontal or vertical especially when subject to continuous vibrations, thermal or construction movement, mechanical reinforcement should be considered and be ideally located approximately 2/3 through the spray thickness.

Vermitex^® ‘DX’ and ‘AF’, when applied in ventilated areas to a thickness of 25 mm, will dry in 2 weeks. Vermitex^® ‘DX’ 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. The material can be applied 20 mm thick on steel decks in one application, thicker applications are possible, however this will depend on the state of the background, its water-uptake capacity and the experience of the work Team. Multiple coatings will achieve a smooth and even textured finish, however a new coat should only be applied over one that has partially set. Where this is not possible the last coat ‘surface’ should be left with a ‘deep & rough texture’ or be purposefully scratched. When ‘Trowelling’ or ‘Ruling’ is unavoidable the applicator should not ‘overwork’ or ‘polish’ the sprayed material.

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

Vermitex^® ‘AF’ can only be used for interior applications. Vermitex^® ‘DX’ in exterior locations may require protection by topcoating. In certain applications, Vermitex^® ‘AF’ may be applied directly onto the bare steel without the need for a steel primer (Refer to LAF for further detailed advice). Exterior steel surfaces must be galvanised or otherwise be suitably primed (Refer to LAF for details).

Bond Coat, Primer Compatibility and Corrosion prevention

When applying Vermitex^® ‘DX’ and ‘AF’ to decking elements without the aid of mechanical reinforcement a ‘Bond Coat’ equal to Vermitex^® ‘7’ is mandatory. No specific thickness is required when spraying Vermitex^® ‘7’, however coverage of between 50 and 75 % of the area is required. Vermitex^® ‘7’ will enhance the adhesion of the Vermitex^® ‘DX’ and ‘AF’ to the substrate, facilitate the application as well as reduce material ‘slippage’ on smooth vertical backgrounds.

Painted structural decking will need special attention, as some paints (acrylics in particular) will impair and at times preclude proper adhesion of the Vermitex^®. In these cases the paint should be totally removed or mechanical retention employed (i.e. mesh, discontinuous fixings, etc.).

The paint composition and the deck configuration (eg, re-entrant profile etc.) are likely to determine which remediation process will provide the best and most cost effective outcome (2).

If a concern exists about moisture presence or ingress, the substrate should be suitably primed with an approved coating. Chemicals which have an impact on cement or plaster will also have an impact on Vermitex^® ‘DX’ and ‘AF’, in these circumstances the Vermitex^® ‘DX’ and ‘AF’ must be top coated with suitable protective coatings (Refer to LAF for more details).

Only stainless steel protective ‘Angle Corner Beads’ should be used for exterior applications. Vermitex^® ‘7’ and ‘DX’ may react with Aluminium and Aluminium alloys and a suitable primer is recommended.

Coverage

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

Vermitex^® Specification (Broad Form)

The Main Contractor should proceed with spraying operations once all heavy construction work (core drilling, jack-hammering, drilling with percussion tools, and heavy equipment movement etc) likely to generate severe vibrations, have been completed.

Before commencing the Vermitex^® ‘DX’ and ‘AF’ application, the substrate shall be inspected by the Main Contractor to ensure all elements to be sprayed are free from any substance, which impairs adhesion of the spray material. (2)

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

Vermitex^® ‘DX’ 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^® ‘DX’ & ‘AF’ Thickness Table

Tested to AS 1530.4 (minimum concrete cover 100 mm)

N.B. - Highlighted Grey cell denotes Mechanical Reinforcement is required.

Health Statement

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

Notes:
1. Refer to LAF for mesh requirement details and for other Vermitex^® ‘DX’ & ‘AF’ applications
2. Refer to LAF for further detailed information

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

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

Email:sales@lafgroup.com