BF-3506-2

300 × 100 × 1.45 mm C-Steel Purlin (HST300/15) penetrating two layers of BOSS Batt™ (350 mm × 475 mm) cut to the purlin profile, with one pattress layer on each wall face, protecting a 170 mm × 325 mm aperture. The purlin is to rest on the base of the aperture in the separating element. All batt edges are coated with BOSS Ablative Coating, and BOSS FireMastic-300™ is applied between the batt and substrate and to its edge.
Two laminated batts are inserted into the purlin opening, extending 580 mm each side, with FireMastic-300™ between batts and purlin. On each side, 580 mm of BOSS Thermal Defence Wrap (two layers, 300 mm long, 20 mm overlap) is fitted, sealed at the BOSS Batt™ with FireMastic-300™.