The wall finish of the framed inner leaf of the external wall should be:
Diagram 2-9: Wall type 1 – external cavity wall with timber frame inner leaf
2.42 No guidance available (seek specialist advice).
2.43 There are no restrictions on internal framed walls meeting a type 1 separating wall.
2.44 Internal masonry walls that abut a type 1 separating wall should have a mass per unit area of at least 120 kg/m2 excluding finish.
2.45 If the floor joists are to be supported on a type 1 separating wall then they should be supported on hangers and should not be built in. See Diagram 2-10.
2.46 An internal concrete floor slab may only be carried through a type 1 separating wall if the floor base has a mass per unit area of at least 365 kg/m2. See Diagram 2-11.
2.47 Internal hollow-core concrete plank floors and concrete beams with infilling block floors should not be continuous through a type 1 separating wall.
2.48 For internal floors of concrete beams with infilling blocks, avoid beams built in to the separating wall unless the blocks in the floor fill the space between the beams where they penetrate the wall.
Diagram 2-10: Wall type 1 – internal timber floor
Diagram 2-11: Wall type 1 – internal concrete floor
2.49 If the floor joists are to be supported on a type 1 separating wall then they should be supported on hangers and should not be built in.
2.50 See Building Regulation Part C - Site preparation and resistance to moisture, and Building Regulation Part L - Conservation of fuel and power.
concrete slab may be carried through if mass per unit area is at least 365 kg/m2 Resistance to the passage of sound
Approved Document E 22