Technical Booklet G Resistance to the Passage of Sound·Page 46·2.76
Framed inner leaf of external cavity wall - construction and finishing
Where an external cavity wall has a framed inner leaf, it must abut and be tied to the separating wall, and must be finished with specific plasterboard layers and sealed joints.
Where the inner leaf of an external cavity wall is of framed construction, the framed inner leaf should –
(a) abut the separating wall; and
(b) be tied to it with ties at not more than 300 mm centres vertically.
The wall finish of the inner leaf of the external wall should be –
(c) one layer of plasterboard; or
(d) two layers of plasterboard with staggered joints where there is a separating floor; and
(e) each sheet of plasterboard to be of minimum mass per unit area 10 kg/m2; and
(f) all joints should be sealed with tape or caulked with sealant.
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