WJ Group was formed in 2007 as a timber engineering business by owner, Mark Eggleston. The group now employs over 70 staff between Hull and Kirkburn, with a further six in Kent.

The FireWright part of the group is based in Kirkburn and is the first in Britain to offer eco-friendly fire retardant timber treatments and has become a leading presence with a number of high profile partnerships and projects to its credit.

WJ Fire Retardant is also set to double its capacity with the help of a new investment in 2023. Since 2019 it has doubled its turnover and is on course to double again in the next five years ahead by installing additional kilns and boosting production.

When it comes to timber in construction, fire retardancy is all about creating time by minimising fire contribution, smoke development and creation of more burning material.

Timber is gaining popularity in construction. It is a global trend with increasingly large, tall and complex buildings using timber for facades, internal surface finishes and structural support.

Whilst timber’s aesthetic appeal, environmental credentials and engineering flexibility are driving this trend, designers must ensure that buildings remain safe over the long-term. Key to this is making sure that construction timber treatment is correctly specified to meet the regulatory demands, which themselves have developed as sub-systems within an overall design that primarily protects lives and then minimises damage.

Due care must be exercised to maintaining that system over the life of the building and consideration given to possible future change of use. Fire retardant timber is as much a part of that whole life design so the performance of that treatment must also be maintained.

CERTIFICATION AND ASSURANCE

Untreated timber is combustible and as such is defined as an E Grade material. Concrete, steel and similar materials are typically A1 Graded – No Contribution to Fire. Correctly chemically engineered and processed fire retardant timber can achieve a B grading.

In terms of timber in construction the highest possible grading is: B, S1, d0 which looks like figure 1:

Factory processing of fire rated materials requires the processor to achieve, then maintain a level of production control, repeatability and audit trails to assure the material’s users of its performance. This control and documentation must be applied to every batch and be retained for review before the treated material can be UKCA or EU CE marked.

In summary, UKCA or EU CE marking requires three certification elements to be present before it can be applied (see figure 2). Individually these cover the material variant, the processing environment and the history of each specific batch. Without these in place it is hard to see how users can be assured that their timber is fire retardant to a known performance threshold.

BUILDING SUSTAINABILITY

Where the treatment has been applied to the surface of the timber – for example by hand, on site during construction – then the timber should be regularly assessed to ensure all the applied treatment is undamaged and maintains the certified thickness. Where it is damaged or has thinned through weathering it should be recoated following the manufacturer’s instructions.

If the timber has been pressure impregnated then it may not require the same degree of ongoing monitoring and repair. Ideally the timber should be impregnated throughout, which means that accidental damage will not reveal untreated wood. Arguably this is the most sustainable approach as once treated there’s no further work needed to maintain the timber’s fire retardancy performance. It can also be much better value in terms of cost too.

Due attention should also be given to the chemicals used in the treatment. FireWright uses a treatment which is no more dangerous than lemon juice and can provide assurance of the highest possible levels of certified timber fire retardancy performance. This transforms combustible timber into a fire retardant material that is environmentally friendly, requires no special handling either in construction or recycling and, vitally, no repeat treatments.

YORK ST JOHN UNIVERSITY

The York university has been at the heart of its community for more than 180 years. It has one of the best city centre campuses in the UK – making it an impressive, high-profile project to be involved in. Our FireWright team treated the Russwood-supplied Siberian larch timber to ensure it was entirely fire retardant. We then applied black and clear coatings to create the striking exterior for the newbuild Creative Centre and its standout interior walls and ceiling.

We worked alongside leading sustainable architects Tate + Co and BCL Timber Projects on the project. The scheme took just six months to complete in 2021.

GREAT YARMOUTH MARKET PLACE

Great Yarmouth’s new indoor market is already at the heart of the community, housing food and retail units in a state-of-the-art new space.

We played a key role in bringing the multi-million pound project to fruition and securing its long-term safety. The full Siberian larch timber façade was treated by FireWright to protect the structure, as well as the statement wood panelled ceiling and walls.

The project was designed by Chaplin Farrant Architects and completed by Pentaco Construction Ltd using timber supplied by Russwood.

And there’s more to come. While phase one of the Market Place project is complete, keep an eye out for phase two which is planned for 2023.