Sawn treated timber in smaller sections are commonly known as battens. Battens are available in three common dimensions 25x50mm, 25x38mm and for the refurbishment market in 19x38mm.
Imported none graded Battens are usually referred to as Type A. These are not suitable or allowed on NHBC new build sites.
Individual pieces are marked for full identification, highlighting size species, grade (TB33) and treatment process. High pressure preservative treated to BS:8417:2003 (UC2) which carries 60 year service life against insect attack and wood rotting fungi.
Visually graded at source the TB33 meets all aspects of BS5534:2003+A1:2010 with the exception of a final grade for knots, which must be carried out on site. This exercise is something that we would expect all roofers to do with all battens anyway given the nature of use.
All battens are manufactured from European Redwood (PNSY) or European Whitewood (WPCA).
The TB5534 is a premium batten available in 25mm x 38mm and 25mm x 50mm. This batten, as TB33, is fully graded to meet all aspects of BS5534:2003+A1:2010 but also includes a final grade for knots. Thereby eliminating the need for grading on site (which is now a requirement for all NHBC homes).
The TB5534 batten is independently accredited by BM Trada.