Treatment systems
Burnblock® fire retardant treatment for timber cladding
Burnblock® is a fire retardant treatment widely used on timber cladding in the UK. We work with specialist treatment partners to supply cladding treated with Burnblock® and other systems. Treatment is carried out by a third party, FireWright (WJ Group), using Burnblock®.
This page explains what the treatment is for, how the supply process works and what paperwork to ask for. It does not state a classification for any particular board: that comes from the certificate for the species and profile you choose.
About the treatment
Burnblock® is applied to timber by specialist treatment companies and is designed to improve its reaction to fire so that the finished cladding can meet a Euroclass target, subject to the species, profile and installation conditions on the certificate.
It is used on both interior and exterior cladding, and it is often specified where a Euroclass B target is needed together with a painted or natural finish. Treated boards can usually be finished with approved paints and coatings, which allows a wide range of colours and looks.
Like any fire retardant treatment, it makes timber react to fire more slowly. It does not make timber non-combustible, and it does not replace sensible detailing such as cavity barriers and fire stopping.
How the supply process works
- You tell us the species, profile, quantity and the class you need.
- We supply or source the cladding and arrange treatment with our specialist partner.
- Treated boards are dried, inspected and supplied with the paperwork you need.
- Boards are finished if required and delivered to site.
Finishes and coatings
Finishes can be applied once the boards have been treated and dried. Whichever coating you choose, check that it is approved for use over the treatment and covered by the certificate. A different paint or oil from the one tested may change the result.
If you want a factory-applied finish, say so at the enquiry stage so treatment and finishing can be planned as one sequence. Where boards are cut on site, ask for the guidance on treating cut ends, and keep treated boards dry in storage and during installation.
Over time, weathering and wear can affect any coating. Ask for the maintenance and re-treatment advice that goes with your certificate, and keep a record of what was applied and when.
Other treatment systems
We can arrange cladding with a range of fire retardant systems, so we can match the product to your project, certification and budget. Our treatment systems page compares Sentrin, Dricon, Fire-X, HR Prof, Treet and others. Tell us what you need and we will advise on the options and certification.
Paperwork and certification
- Classification reports and certificates for the treatment system.
- Batch and treatment records for traceability.
- Guidance on installation, cavity barriers and finishes.
- Maintenance advice, including re-treatment where relevant.
Contact our team for the documents that apply to your species and profile. Keep them with your project file, as Building Control may ask to see them.
Shop and specify
Frequently asked questions
Talk to our timber team
Tell us about your project and we will recommend the right species, profile, finish and fire performance. Free samples are available, and we can quote for bespoke milling.