Unit installation

non-combustible sleeve 203mm (8in.) diameter will be required round the flue (See
figure 11).
!
Cut a hole through the inner leaf to accommodate a non-combustible sleeve 203mm
(8in.) outside diameter. To minimise the effect of breaking through the vapour control
layer (VCL), if possible, cut the hole approximately 10mm undersize so that the sleeve
will be forced through the layer. A recommended technique for cutting the inner leaf is
shown in figure 11.
!
Fit the non-combustible sleeve to the inner leaf. The sleeve must extend to be at least
flush with the breather membrane/timber sheathing but must not protrude more than
10mm into the cavity.
!
The annular gap between the flue unit and the sleeve must be sealed to prevent air
heat and moisture passing along it. The 12.5mm insulating sheet (See section 7.3) can
be used for this. Do not permanently fix the insulating sheet to the wall at this stage
(See section 8.2).
7.6 Prepare appliance fixing holes.
7.6.1 Screwing case to wall.
! Recheck the position of the screw fixing holes relative to the flue hole.
! Drill the four fixing holes to a minimum depth of 42mm using a 7mm diameter
masonry drill.
Page 18
INSTALLER GUIDE
Figure 11. Timber frame
wall preparation