Flavel Rocco HE FPHL RN2 Series Installation, Maintenance & User Instructions page 10

Fig. 7
400mm interactive area
600mm load triangle
The opening needs to be sufficient to accomodate the combustion chamber. To
support the wall above the opening, a suitable lintel must be inserted across the
top of the opening. The lintel could be either pre-cast concrete or steel - Catnic
CN52 or CN 46 could be used, depending upon the inner wall thickness. Before
proceeding with the installation of the fire, an assessment of the area immediately
above the fire is required, see figure 7 above. If there is no existing openings
within either triangle, proceed with forming the opening. However, if opening or
beams occur within either triangle, then you should seek specialist advice from a
structural engineer or consider relocating the proposed position of the firebox.
Proposed Opening in
Chimney Breast
9
The Interactive Zone -
Openings, beams or joists within
this area need to be assessed.
Load triangle - No beam or
opening permissible within this
area
Lintel
e.g. 750mm x 75mm