Burnblock, Sentrin, Dricon, Fire-X, HR Prof and Treet
Fire retardant treatment systems we can arrange
There is no single fire retardant treatment for every project. Systems differ in how they are applied, whether they suit exterior exposure, which species they work with, what finishes they allow and what rating the certificate supports. We can arrange cladding treated with a range of systems, so we can match the treatment to your design and compliance route.
The summaries below are for orientation. What a system achieves on a particular board depends on the species, thickness, profile, cavity and finish stated on its classification report, so always ask for the current certificate.
Systems at a glance
| System | Type | Where it is used | Notes |
|---|---|---|---|
| Burnblock® | Specialist treatment applied by our treatment partner | Interior and exterior cladding | Often specified where a Euroclass B target and a painted or natural finish are needed |
| Sentrin FRI / FRX | Pressure-impregnated retardant (Arnold Laver) | FRI for interior and sheltered use; FRX for external use | Can achieve Euroclass B or C depending on the version and conditions |
| Dricon® / FRX (including non-combustible treatment) | Pressure-impregnated fire retardant treated wood (Arxada, formerly Lonza) | Dricon for interior use; FRX for exposed exterior use; non-combustible treatment where a project calls for it | Developed for North American codes: check the UK or EU classification and the current certificate for your project |
| Fire-X | Fire retardant treatment system | Cladding and joinery | Ask us for the current certificate and the species and profiles it covers |
| HR Prof | Water-based impregnating treatment | Interior and exterior cladding, log cabins, saunas | Supplier cites Euroclass B and UK Class 0; not suitable for Accoya or thermally modified hardwood |
| Treet | Bio-based, waterborne flame retardant that can double as a surface finish | Facades, cladding, panelling and slats, internal and external | Manufacturer cites up to B-s1,d0 on certain conifers including spruce, larch, cedar, Douglas fir and pine |
Burnblock®
Burnblock® is applied by a specialist treatment partner and is a popular route to a rated cladding that can still be painted or finished in a natural look. See our Burnblock page for the supply process and paperwork.
Sentrin FRI and FRX
Sentrin is a family of pressure-impregnated fire retardants from Arnold Laver. The timber is treated in an autoclave and then kiln dried at an elevated temperature. Sentrin FRI is intended for interior use, or exterior use where the timber is sheltered from direct rain. Sentrin FRX is the external version, designed for weather exposure. Depending on the version and conditions, classifications of Euroclass B or C are possible.
Dricon®
Dricon® is a well-known fire retardant treated wood, originally from Lonza and now supplied by Arxada. It is a pressure-impregnated product, with Dricon intended for interior use and a companion FRX exterior product for exposed applications. It was developed for North American building codes, where it is accepted as an alternative to non-combustible construction in some situations.
We can also arrange Dricon® non-combustible fire treatment for projects that call for it. What it achieves, and where it can be used, depends on the specific product, species and the certificate that applies, so tell us the requirement and we will send the current documents.
Fire-X
Fire-X is another fire retardant treatment we can arrange for cladding and joinery. Tell us the species, profile and rating you need and we will confirm what can be treated and send the certificate that applies.
HR Prof
HR Prof is a water-based, leach-resistant impregnating treatment, described by its suppliers as colourless and solvent free, for timber used inside and outside, including cladding, cabins and saunas. If you want to paint the timber afterwards, the fire retardant goes on first, followed only by compatible paints.
Treet
Treet is a bio-based, waterborne flame retardant that can be clear or semi-translucent tinted, so fire protection and surface finish can be combined in one application. It is intended for both interior and exterior timber including facades, cladding, panelling and slats, on conifers such as spruce, larch, cedar, Douglas fir and pine.
How to choose a system
- Start with the class you must achieve and the route to compliance agreed with Building Control.
- Decide whether the cladding is exposed to weather, sheltered, or interior.
- Choose the species and profile, and check the system is certified for them.
- Choose the finish and make sure it is covered by the certificate.
- Check lead times, particularly if the timber must be treated, dried and finished before delivery.
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.