By Rebecca Goldsmith, product marketing executive at MEDITE SMARTPLY
WOOD panel products incorporating flame retardant treatment will slow down the development of a fire, allowing more time for building occupants to escape and the fire to be extinguished – but it is vital to ensure panels will perform effectively.
In the UK, the section of the Building Regulations that deals with fire is different in each UK jurisdiction: in Scotland it is ‘Technical Handbooks’ while in England and Wales it is ‘Approved Document B’.
However, while the title of the documents might differ, the regulations are similar in that they require products to achieve a defined level of fire performance in specific areas of buildings.
Pre-treating timber panel products with flame retardants will improve the performance of wood and wood-based materials in fire situations to meet the level of performance required by Building Regulations.
The European Standard BS EN 13501-1 defines seven levels (Euroclasses) of fire performance. Products are classified A1, A2, B, C, D E and F. A1 and A2 are the highest performing Euroclasses these are for non-combustible products, assessed as a making no contribution to a fire; Class F is the lowest Euroclass. Because wood is a natural organic material, Euroclass B is the highest classification it can achieve, which is described as having ‘Very limited contribution to fire’.
The Construction Products Regulation 2011 (CPR) is a European Union regulation harmonising the performance information on construction products across the EU. CE marking is mandatory for all construction products placed on the market in the European Economic Area. Wood-based panels are covered by harmonised European standard EN 13986 and are therefore required to be CE-marked as a declaration that the product complies with European health and safety and environmental legislation.
How specifiers and installers can ensure the timber panel products they specify are CPR compliant
The straightforward route: Where flame retardant is added to wood panels in the factory during the manufacturing process, such as for SMARTPLY MAX FR Euroclass B OSB, the manufacturing process will be subject to factory production control (accredited by a notified body) for structural and reaction to fire performance. This ensures that the product will carry a valid CE mark for its enhanced fire performance.
The complicated route: A distributor of non-flame retardant wood panels could choose to send the material to a third party for post-manufacture flame retardant treatment, before selling that treated stock on the open market. Where this is the case, the distributor takes on the responsibilities of the manufacturer for CE marking.
End users should be aware that products which have a CE mark applied prior to treatment will require a new DoP to be issued after treatment to declare the improved reaction to fire classification, and any change in the non-fire (e.g. structural) properties that may have occurred through the process of treatment. This activity will require the involvement of a third party notified body.
The even more complicated route: An alternative option is the surface application of flame retardants on site using brush or spray. With coatings applied on site it is rarely possible to guarantee quality in this application’s effective performance. For this reason, the Wood Protection Association will only approve such systems when applied under factory-controlled conditions.
In conclusion, where absolute certainty of fire performance is needed, a pre-treated panel is reccomended, and the reason why MEDITE SMARTPLY always ensure that all their flame retuardant panels are treated before pressing, so that all fire protection is integral.