Treated UC4

UC4 treated timber is wood that has been through a complex tanalised pressure treatment process to render it resilient to environmental conditions. This reduces its likelihood of succumbing to rot, and dampness and improves its ability to last for a long time when in permanent contact with the ground outside.

Most timber frames sit at ground level, or just above it. To get the best service life from your timber it should be UC4 treated, with good air circulation, and preferably away from ground contact. Our UC4 treated timber and UC4 treated sleepers are incised and treated for longevity. 

Timber used for UC4 Joists

Home-grown (ie.British) spruce is used for the incising of some decking joists, UC4 treated sleepers and decking boards. Home grown spruce grades to C16 The timbers are kiln dried and monitored to reduce the product’s moisture level. When everything is in order the timbers, which are in vacuum tanks, are flooded with preservatives.  

Best practices for UC4 timber

Standard carcassing timber is normally UC2, not a problem for projects where the timber will only experience occasional wetting until the building is watertight. However, if you have a timber-framed building where the timbers are likely to be in ground contact then UC4 timber should be used.  Whatever grade you use, any cut ends must be treated with a recognised end-grain treatment. 

For this reason, UC4 treated sleepers are ideally suited to making raised vegetable beds or garden retainers; in fact, our range of pressure treated UC4 timber is ideally suited to all your outdoor landscaping projects, What's more, all our UC4 treated sleepers come with an attractive 15-year warranty for your peace of mind.