INSTALLER’S GUIDE
Page 14
Figure 8 Timber frame wall preparation
5.12 Combustible Walls (Wood, Fibreboard, Plasterboard etc.)
Building regulations require that the inlet and outlet ducts and terminal bust not be closer
than 25mm to combustible material.
5.12.1
Mark out and cut a hole 202mm diameter through the combustible part of the
wall. A 152mm diameter hole can be cut through non-combustible parts of the wall (see
figure 7).
5.12.2
Cover the hole with a rectangular sheet steel plate 500mm x 235mm with a
152mm diameter hole cut out of the centre (see figure 7). The steel should be not less
than 1.5mm thick. Fix with suitable screws and plugs.
5.12.3
Where the whole wall is of combustible material, a non-corrosive plate
455mm x 455mm with a 152mm diameter hole in the centre must be fitted to the outer
wall. The hole through the wall should be lined with a non-corrosive metal tube 202mm
diameter
Cut the Flue Hole –Timber Frame Buildings
Drill the pilot hole and hole in outer wall as section 5.5.
