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Why do you include OSB in your roof build-ups?

Chris Brookman
Member Admin

The OSB is included in the roof build-ups as a support layer underneath the rafters for the flexible wood fibre insulation between the rafters. It can be used as the VCL and airtightness layer if 15mm OSB is used or the ProPassiv boards are used but usually we include this layer as a practical way to support the installation of the insulation. If the flexible wood fibre gets wet during installation it will fall out and also it is heavy so if it does drop post-installation this is a lot of weight to carry on the membrane or plasterboard layer underneath.

Topic starter Posted : 10/02/2021 11:39 am

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