This is a summary of a report assessing the condition of a natural exposure trial set up at the premises of Teknos (UK) Ltd near Swerford in Oxfordshire in March 2009, which ran for over 10 years. The report was commissioned by Accsys Technologies Plc; it was assessed and written by BM Trada in 2019.

The aim of the trial was to test the long-term performance of different wood cladding profiles fabricated in three different substrates:

• Western red cedar
• Siberian larch
• Accoya® Wood

The report looked at the condition of the test rigs after 10 years and 9 days of uninterrupted natural exposure without any form of maintenance. The three test substrates were used in conjunction with three cladding profiles and different levels of end-grain sealing at board ends, as well as at intermediate joints designed to facilitate water bridging.

Demonstrable improvements in performance can be obtained when the end-grain of wood is protected against water ingress, even in scenarios where moisture is held against vulnerable end grain for prolonged periods

The report concluded that demonstrable performance benefits can be achieved, when used in association with good endgrain sealing practice and board profiles with rounded aris details which facilitate water shedding. The report found that, when used in concert with Accoya®, the anticipated lifespan to first maintenance of a
transparent medium-build stain finish can be extended by as much asthree times compared to unmodified softwoods.

I'm interested in:

• Accsys Technologies PLC
• Durability
• modified wood products
• Moisture