Internal Fire Protection for Timber

Internal Fire Protection

We work closely with PTG Treatments Timber Protection to supply products that are designed to be as practical as they are beautiful. Materials are treated to ensure effective fire protection performance that will last the lifetime of the timber product.

Sentrin FRI treated wood products have been tested to BS EN 13501-1:2002; Fire classification of construction products and building elements


Matching Range of Accessories

  • Fibre Cement Trim NT3
  • Metal Trim
  • Starter Profile
  • Top Vent Profile
  • EDPM Tape
  • HardieSeal Edge Coating




  • Gecko Gauges
  • Guillotine
  • HardieBlade Saw Blades


Benefits to the Homeowner

  • Made to Last – Fibre cement technology has an expected life span in excess of 60 years. Enhanced durability and lasting resistance to fire, rot, rain, hail & wind.
  • Low Maintenance – Won’t crack, peel, warp or sag over time. With ColourPlus ™ Technology, a multi coat, baked on finish that’s fade resistant and does not need regular repainting.
  • Flexible Design – 5 stocked decors. Can be installed horizontally, vertically, traditional shiplap or open joint style.



Benefits to the Contractor

  • Fire Resistant – Non-combustible with a fire classification of A2, s1 d0
  • Easy to Install – Lightweight material, tools available for speedy install, technical support
  • Flexible Design: multiple installation styles using our range of 5 stocked colours. Other colours available on extended lead times.
  • Protect Your Work – Global leader in fibre cement, BBA cert to 60+ years, 10 year warranty
  • No Wet Trades – No specialist sub trades required, can be installed all year round

Sentrin FRI

Sentrin FRI fire retardant treated timber has been pressure impregnated with a humidity resistant, high temperature fire retardant formulation (Osmose FirePRO). It has been processed under ISO9001 controlled factory conditions to provide confidence in performance and long lasting protection without further maintenance. Treated timber can meet the requirements of national Building Regulations where Euroclass B or C are required and will significantly reduce the spread of fire, heat generation and smoke generation. These fire performance properties do not compromise critical engineering properties such as strength, durability, corrosivity and hygroscopicity.

Sentrin FRI treated wood products have been tested to BS EN 13501-1:2002; Fire classification of construction products and building elements. These ‘reaction to fire tests’ are used to generate classifications of flammability which are commonly specified in building regulations. To specify the correct level of protection the following information is required:

1. Timber species or plywood type and dimensions.
2. Euroclass required (C or B).
3. End use application (must be weather protected).

Sentrin FRI treated wood products meet the requirements of HR (humidity resistant) and DI (dry internal) specifications. It is approved by London Underground for use in construction and maintenance projects. Certificate ID 1327 Osmose FirePRO.

Read our Sentrin blog post for more info


Treatment Process

Treatment is carried out in high pressure autoclaves to penetrate fire retardant into the timber to achive the required classification. Timber is loaded into the treatment vessel and the door sealed. A vacuum is then created inside the to remove air from the timber. The vessel is flooded with fire retardant solution and high pressure applied to penetrate into the timber.

After the solution is removed a final vacuum is created to remove excess liquid. The liquid is returned to storage and there is no waste generated from the process. The freshly treated timber is then held undercover until it is drip dry before being kiln dried to its desired moisture content. Process times vary with the treatment specification but are typically between 90 and 240 minutes.



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Part of the UK's largest independent timber group, Arnold Laver offers high-quality timber at scale