The layout of the fourth layer is dependent on the flue
pipe connection.
If the connection faces upwards, the back half
(consisting of 4 bricks) is placed inside first, and then
two bevelled bricks are placed at the front (with the
bevels facing upwards). ¼ of each of the top layers is
not shown in the diagram to make the illustration clearer.
The first layer is
completed using two
segment heat-storing
bricks to form a closed
ring.
In the second layer,
the bevelled bricks
are "reversed" and
placed on the
bevelled bricks in the
first layer. . .
. . . then the
second layer is
completed with two
segment heat-
storing bricks.
The third layer is
started with two
segment heat-storing
bricks and
completed with two
bevelled bricks.
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If the connection is to the rear, the rear half of
the fourth layer only consists of 2 bricks, the
two smaller bricks are left out, and then two
bevelled bricks are placed at the front again
(with the bevels facing upwards).