Working in collaboration with Arch Timber Protection’s research scientists, Glenalmond Timber Products has developed a treatment to ensure its UltraJoist timber joists stay super dry during storage, transport and construction.
Current legislation requires structural timber for internal applications to be supplied with an average moisture content of 20%. Once installed in centrally heated buildings, this can drop to 10-15%, and shrinkage and associated damage can occur.
UltraJoist’s C16/C24 joists are ‘super-dried’ to an average 14%mc which overcomes this problem. But while super-dry timber has been available for some time, the difficulty has been how to prevent it taking in moisture again after it leaves the kiln.
In conjunction with Arch, UltraJoist has developed a preservative that not only provides effective protection for Hazard Class 1 & 2 applications, but also has water repellent properties that substantially reduce water ingress from rain or ambient moisture.
This has proved a boon to developer Prestoplan which uses UltraJoist solid timber joists for the upper-storey ring beams in its timber frame buildings.
Prestoplan operations director Andrew Underwood said the company had a strict policy of reducing shrinkage, the structural impact of which is cumulative and of particular concern with higher storey buildings. He added: “Since our first order we’ve used UltraJoist products whenever that policy applies.”
