Find out more about a typical high pressure treatment:

The resulting TANALISED™ timbers and VACSOL™ Aqua treated timbers can be used with real confidence in a wide range of end uses and timbers are treated to suit the relevant Use Classes shown below.

TANALISED™ timbers can be used throughout Use Classes 1-4. VACSOL™ Aqua treated timbers can be used for Use Classes 1, 2 and 3 coated. For Use Class 3 coated an appropriate and well maintained surface coating must be used on the VACSOL™ Aqua treated timbers to maintain the integrity of the preservative protection.

The eventual end use of preservative treated timber is classified into one of the five main categories shown in the table below. These Use Classes, defined in BS EN 335-1, are based on the potential threat to the timber from decay or insect attack in its eventual application.

For instance, internal building timbers in Classes 1 and 2 will be under less threat than timbers used externally in ground contact – Use Class 4. Therefore, Use Class 4 timbers will require a higher degree of protection. Next generation TANALISED™ pressure treated timber can be used with total confidence in Use Classes 1 – 4.

Always ask your supplier which Use Class the timber is treated to, particularly for ground contact applications.

• UC 1 – Internal, dry (eg. Upper floor joists)
• UC 2 – Internal, risk of wetting (eg. Tile battens)
• UC 3 coated – Outdoors, coated, above ground (eg. Soffits/Cladding)
• UC 3 uncoated – Outdoors, uncoated, above ground (eg. Cladding/Fence rails)
• UC 4 – Direct soil or fresh water contact (eg. Fence posts)

Arnold Laver can offer a choice of tried, tested and proven fire retardant treatments for timber and board products wherever a fire protection is required by Building Regulations.

Sentrin FRX fire retardant treated timber has been pressure impregnated with a leach resistant (Type LR), exterior grade fire retardant formulation. It has been processed under ISO9001 controlled factory conditions to provide confidence in performance and long lasting protection without further maintenance, even in fully weather exposed situations.

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.

Both treatments can be supplied to meet either Euroclass B or Euroclass C ratings in accordance with BS EN 13501-1 within the Construction Products Directive.

Both treatments are carried out in ISO 9001 Quality and ISO 14001 Environmental accredited facilities.