1. Standards and Classifications

Osmose FirePRO fire retardant treated wood products (FRTW) have been tested to BS EN 13501-1:2002 "Fire Classification of Construction Products and Building Elements". These tests are commonly referred to as 'reaction to fire tests'. Reaction to fire tests are commonly called up in regulations in both the building and transport sectors. The classifications of flammability are detailed in the table below along with the UK transpositions of the more traditional BS476 Classifications

Treated with Osmose FirePRO, timber and wood based panels can achieve either Class B or Class C. Osmose FirePro is suitable for treatment to WPA Fire Retardant Commodity Specifications FR1, FR2, FR3 and FR4.

2. Specification Clauses and Codes

T

Specification Code Euro Class Typical Component Kiln/Air Dried 5PFC1 5PFB1 C B Plywood 3.6mm Kiln 5PFC2 5PFB2 C B Plywood 5.5mm Kiln 5PFC3 5PFB3 C B Plywood 9mm Kiln 5PFC4 5PFB4 C B Plywood 12mm Kiln 5PFC5 5PFB5 C B Plywood 15mm Kiln 5PFC6 5PFB6 C B Plywood 18mm Kiln 5PFC7 5PFB7 C B Plywood 21mm Kiln 5PFC8 5PFB8 C B Plywood 24mm Kiln 5PFC9 5PFB9 C B Timber Kiln

reatment Specification Codes for Osmose FirePRO

Model Specification Clause: 

The material as detailed (insert quantity, material, species) to be treated to (Euroclass B or C) using a WPA Type HR humidity resistant process to the specification code (see above).

Note:

• For more information on WPA (Wood Protection Association) Treatment Types and Specifications please contact us.
• A supplement to Building Regulations Approved Document B has been issued to include Euroclasses for fire performance alongside the British classifications. The UK transpositions are:
• Euroclass C - - - UK Class 1
• Euroclass B - - - UK Class 0

3. About Osmose FirePRO Treated Wood

Osmose FirePRO* fire retardant treated wood (FRTW) products are pressure impregnated with an Osmose FirePRO, an interior high temperature fire retardant chemical formulation based on proprietary Osmose technology.

Historically, fire retardants have depended upon phosphorus based compounds to achieve fire performance properties. While the unique Osmose FirePRO chemistry contains no phosphates, independent testing performed in accordance with industry standards has shown Osmose FirePRO FRTW products exhibit fire performance properties without compromising other critical engineering properties such as strength, durability, corrosivity, and hygroscopicity. Osmose FirePRO FRTW products exhibited strength durability, low hygroscopicity, and resistance to fastener corrosion.

Application

Osmose FirePRO FRTW products are permitted for use in interior, above ground applications where the adopted building regulations permit the use of wood products or fire retardant wood products such as: roof systems, cladding, sheathing, joists etc. It can also be used in certain exterior applications when protected with a suitable and maintained coating system. Osmose FirePRO is a humidity resistant (WPA Type HR) treatment. The specifier and/or end user is responsible for reviewing the test data on Osmose FirePRO FRTW products to determine if they are acceptable for the intended end use.

Working Properties

After treatment, exposure to rain, snow, or mud must be avoided. Osmose FirePRO FRTW products must be stored indoors or under sheets that offer protection from the elements. Osmose FirePRO FRTW can be cross cut and drilled, but not planed or rip sawn. There are no limitations on the milling or cutting of Osmose FirePRO treated plywood.

Under normal temperature and humidity conditions, most latex and oil-based paints and stains can be used with Osmose FirePRO FRTW products. It should be noted that the use of some paints may affect the fire properties of the end product and care must be taken to select an appropriate paint. Always follow the coating manufacturer's instructions.

Use fixings and other hardware which are in compliance with building regulations for the intended use. Use fixings, hardware or any metal products as recommended by their manufacturer.

4. Osmose FirePRO Treatment Process

Osmose FirePRO treating solution is applied to timber products under rigidly controlled conditions using a vacuum pressure impregnation plant. Osmose FirePRO FRTW products must be Air or Kiln dried after treatment to ensure that the required properties of Osmose FirePRO are obtained.