Fig. 5
To proceed with the installation when the above stated criteria have been
satisfied :-
Mark out where possible, centrally beneath a block joint where the lintel is to be
fitted. Unless lime mortar has been used it will be necessary to drill four holes
with a masonary drill, then use a mechanical cutter such as a “shark saw” to cut
out the correct size of slot in the inner leaf of brickwork for the lintel you have
chosen to install. See fig. 6 below.
Fig. 6
Fit the lintel, ensure that it is bedded on mortar. Do not bed on a dry bed.
Then remove all debris from the cavity and construct the opening to the minimum /
maximum opening sizes as shown overpage (fig. 7) and in section 1.4, (fig. 3)
8
Opening Height
550mm Minimum
570mm Maximum
Firebox recess in
wall
400mm interactive
area
600mm load
triangle
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
50mm Minimum Hearth Thickness
Opening Width
375mm Minimum
440mm Maximum
