The Fire Brick D130 Instruction Booklet page 30

30
3G: ENTRY & VENT COLUMN COURSE 3
Lay bricks L3 and R3, followed by the bricks for next
layer of the vent arch columns. This layer 'keys' into
the entry arch columns, using special bricks which
are easy to identify in your kit. Dry fit these bricks to
ensure you have the mortar joints set correctly.
Don't be concerned if you have a larger gap between
the interlocking bricks and the L3/R3 bricks - these
bricks are cut to allow construction tolerance and the
joints will be virtually invisible once the brickwork is
3H: DOME COURSE 3
Lay Dome Course 3. This is made up of Type 1 bricks,
and small stagger bricks will be needed as keystones
at either end of the row. These may need to be ground
back slightly with an angle grinder to fit neatly.
3I: ENTRY & VENT COLUMN COURSE 4
Lay bricks L4 and R4, followed by the two 25mm
thick 'split' bricks for the next layer of the vent arch
columns.
3J: ENTRY & VENT COLUMN COURSE 5
Lay bricks L5 and R5, followed by the two 'springer'
bricks that complete the vent arch columns.
3. Building the Dome