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INSTALLER GUIDE
Whenever a lintel is required to support the recess
in the inner leaf of a brick/blockwork building,
follow the method outlined below (See figures 11
and 12).
7.4 Lintel installation.
1.
The lintel should be either steel (Catnic) or
reinforced precast concrete. It should be 750mm
long x 75mm deep x inner leaf thickness.
2.
The opening should be, as near as possible,
centrally below a joint in the inner leaf block.
3.
Cut out the opening for the lintel.
Where cutting through masonry, drill pilot
holes and then cut out the slot using a
mechanical cutter. This will minimise damage
to the surrounding structure.
4.
Insert the lintel. Bed the lintel on mortar.
Don’t dry bed.
Slate pin to ensure the lintel and
structure above is secure and safe
5.
Make the opening below the lintel by
removing the masonry and clearing debris. If
the cavity has loose fill (e.g. granular)
insulation material, pack the edges of
the opening with Rockwool as you
proceed to hold back the insulating
material.
6.
The wall cavity must not be bridged
other than by the flue tube assembly.
The fire box must not project into the
cavity between the inner and outer
walls by more than 10mm.
See wall preparation for flue
tube.
The cavity should be sealed where the
opening has been cut. We recommend
filling fully across the cavity with Rockwool or equivalent to at least 100mm all around
the flue tube. Fill at the bottom of the opening to the level of the hearth/fireplace floor.
It may be simplest to back fill the cavity with the insulation material and then cut
through the insulation to the size of the flue box hole.
Figure 13. Flue pipe insulation
Figure 12.
Figure 11.
