4
WALL SHIELDING
The minimum distances between the stove and heat sensitive walls, (shown in Table 1), may be
reduced significantly by fitting a 180° polished stainless steel flue heat deflector on the flue and
suitable heat shield(s) on the adjacent wall(s). Shields must be made of heat resistant material (such as
sheet metal, Harditherm or Supalux) and they must be mounted on the wall on non-combustible
spacers arranged to not obstruct the vertical flow of cooling air in the space between the shield and the
wall. Shields of dense material such as brick and concrete, when mounted in contact with the wall, are
virtually useless.
Ventilation slots must be provided at the top and bottom of each shield, each slot having a cross-
sectional area not less than half the width of the shield multiplied by the spacing depth. The slots
should, as far as possible, extend across the full width of the shield. EXAMPLE: A 1200mm wide
shield spaced 25mm from the wall must have ventilation slots, top and bottom, each of an area not
less than 600 x 25 mm2, i.e. 15,000mm2. So if the effective length of each slot is 1m, it will need to
be 15mm wide.
Three types of shield are recommended:-
* These factors are valid only for vertical shields or shields within 45° of vertical. They do not apply
to shields under horizontal ceilings or ceilings which are less than 45° from horizontal.
To find the reduced minimum distances, multiply the figures in Table 1 by the appropriate clearance
factor.
EXAMPLE: A PITTSBURGH has a normal minimum rear clearance of 850mm and a side clearance
of 900mm. The reduced minimum clearances for type A shielding would be 850 x 0.4 (340mm) at the
rear, and 900 x 0.4 (360mm) at the side.
Table 2. REDUCED MINIMUM WALL CLEARANCES (mm)
WITH A FLUE SHIELD AND WALL SHIELDS FITTED
IMPORTANT:
If the screen material is a single layer and is thick (e.g. concrete or brick), the stove must
be at least 150mm from the face of the screen, regardless of the above allowable
minimum distances between the stove and the wall.
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