The Fire Brick D95, Instruction Booklet

Page: 19 / 47

19
1. Subfloor Insulation
The first step in building your oven is to prevent the heat in the oven floor from being conducted into your
concrete slab, and from there into the surrounding air to be lost forever. We use Calcium Silicate (CalSil) board
to do this, as it has excellent insulating properties, great compressive strength and is easy to work with.
1A: MARK CENTER LINE
Draw a line down the center of your top slab, this is
used to make sure your CalSil board and ultimately
your whole oven is positioned correctly, in the center
of your stand.
1B: CUT OUT CALSIL BOARD USING TEMPLATES
Using the provided paper templates, cut out your
CalSil board pieces using a jigsaw. We have provided
you with thumbtacks to hold the templates to the
CalSil surface.
1C: LAY CALSIL BOARD PIECES ON THE SLAB
Using the center line on your slab and the
corresponding line on the templates, position your
CalSil board pieces on your slab. There is no need to
‘glue’ these pieces down as the weight of the finished
oven will hold them in place.
If your concrete slab is flat and level, you can lay the
CalSil directly onto the slab. If your slab is uneven use
a thin layer of brickies sand to bed the CalSil down, to
ensure that it’s uniformly supported.
Subfloor Insulation
1D: COVER CALSIL WITH FOIL
Cover the top surface of the CalSil board with
aluminium foil, using the drawing pins provided.
Cover the joins with paper masking tape, this makes
the foil surface stronger and less likely to tear.
Transfer the centerlines that you had previously
marked onto your oven stand onto the foil layer.