Subfloor Insulation - The Fire Brick D130 Instruction Booklet

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Subfloor Insulation

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. There are two layers of Calsil Board,
so the parts are marked to help you identify the layer
they belong to.
There is additional information on the templates to
help you set out these pieces.
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. Brickies sand works
well for this purpose as it has a fine clay through it, which helps to keep the sand together and stable.