Summary
• Vacsol FR was launched to meet the market demand from the timber frame industry.
• Ongoing audits and tests will ensure Vacsol FR treated products remain at testing standards.
• Vacsol FR also offers a preservative service life of 60 years.
In recent months, fires that have occurred during the construction phase of timber framed buildings have raised concerns about the use of timber frame as a construction material. These concerns have often been fuelled by ill-informed media speculation and capitalised on by producers of alternative construction technologies and pose a threat to the hard-won credentials of timber frame as a versatile and environmentally advanced construction method. As a consequence, Arch Timber Protection was approached to develop a fire retardant product to help with construction site fire safety management during this period.
Timber behaves predictably in a fire, unlike its counterparts; brick and block flakes and disintegrates under high temperatures, and concrete used in high-rise buildings is subject to the violent phenomenon known as explosive spalling and steel buckling in severe heat. However, the visibility of a burning timber frame makes a much greater media spectacle for some than what may be going on invisibly inside a building during a fire.
But, the issue at hand was not one of fire in completed buildings, rather for those under construction where the framing timbers are exposed and most vulnerable to arson and accidental fire, and where Building Regulations do not yet apply.
There has never been a fire retardant product designed specifically for the construction phase of timber frame. Timber frame components have traditionally just been pre-treated with preservative to protect against fungal decay and insect attack and ensure a long and low maintenance service life.
Product launch
Vacsol FR fire retardant framing timber was launched in July this year to meet the market demand, with Arch researching and developing the specialist technology required after approaches by the timber frame industry. The timber frame components are protected with a formulation that combines both fire retardant and preservative protection. Vacsol FR fire retardant framing timber is treated through a fast and cost-effective double vacuum, low pressure industrial treatment process, which is currently available through service treatment centres in Perth and Preston.
Following the treatment, Vascol FR fire retardant framing timber also comes out of the treatment process with an orange colour that mellows to a tone that acts as a unique identifier for the treatment used.
But what proof exists of the efficacy of such a new product? Because there are no actual Building Regulations that relate to timber frame structures during the construction phase, Arch approached Bodycote warringtonfire, a leading independent fire testing and research body, to establish relevant test criteria. Vacsol FR fire retardant framing timber underwent a range of tests to ensure its performance in a fire and is fully tested and accredited under CERTIFIRE, an independent quality assurance scheme run by Warrington Certification.
Time to escape
Improved surface spread of flame protection, as well as significant reductions in fire growth, smoke generation and heat release, all allow extra time for site personnel to evacuate safely, the emergency services to attend and control the incident, and in turn limit potential fire damage and help to maintain the structural integrity of the building.
An added bonus is the preservative protection also built into the treatment, which provides a subsequent 60-year desired service life against fungal and insect attack once the structure is completed.
Receiving CERTIFIRE accreditation also means that Vacsol FR will undergo continued assessment and auditing to ensure that the product remains at the standards required by Warrington Certification throughout its production life.
Vacsol FR is currently being put into the market, and with the cost of treatment estimated at less than 0.1% of the overall project (costs based on a recently completed, multi-storey, timber frame project), Vacsol FR fire retardant framing timber has been designed to fit into the fire management regime of any future project, particularly high-value buildings, and help allow the continued growth of this environmentally-sound and versatile construction method.
