TGD L 2008 – B.6.3.2W3b – WALL COnSTRUCTIOnS, Construction W3: Timber frame wall, brick or rendered concrete block external leaf

B.6.3.2 W3(b): Insulation between and across studs Where the chosen stud depth is not sufficient to accommodate the required thickness of insulation, insulation can be installed to the full depth between the studs with additional insulation being provided as an internal lining. This additional insulation may be either in the form of plasterboard/insulation composite board or insulation between timber battens, to which the plasterboard is fixed. The vapour control layer should be on the warm side of the insulation. If different types of insulation are used between and inside the studs, the vapour resistance of the material between the studs should not exceed that of the material across them.

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