Louisiana-Pacific (LP) has successfully tested new timber frame wall build-ups that it says can significantly save on material and labour costs.
Its use of FlameBlock fire-rated OSB sheathing and fibreglass insulation passed a two-hour interior burn requirment, earning Underwriters Laboratories approval.
A one-hour exterior burn rating was earned for a similar assembly with mineral wood and exterior cladding.
Normally, two-hour fire rated exterior walls in the US use one or two layers of exterior gypsum sheathing in combination with wood panels.
“The U349 and W408 assemblies, however, utilise LP FlameBlock sheathing as the exterior wall sheathing to meet both structural and fire requirements,” said LP.
LP said use of FlameBlock reduces dead load and can also potentially improve design flexibility due to the sheathing’s superior shear capacity.
FlameBlock is made by applying a fibreglass-reinforced pyrotite coating to OSB panels.
