The Fire Brick D95, Instruction Booklet

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2. Laying the Floor Tiles
Fire bricks are very porous and will absorb a significant amount of water, so if you apply wet mortar to a dry
fire brick this mortar will dry out and will not develop a good bond. To overcome this, soak your fire bricks in
water for at least 10 minutes before you lay them. Take the bricks out of the water shortly before you need
them, then when you grab a brick to lay, give it a dry on a towel or rag to remove any excess surface moisture.
You’ll be using the Hybrid Refractory Bedding Mortar mix shown below to bed the tiles down and get them flat.
Remember - WEAR RUBBER GLOVES. This mortar is alkaline and can cause chemical burns!
HYBRID REFRACTORY BEDDING MORTAR MIXTURE
• 2 PARTS AIRSET REFRACTORY MORTAR
• 2 PARTS WASHED SAND
• 1 PART GP (GENERAL PURPOSE) CEMENT
• 1 PART HYDRATED LIME
These measurements are by volume (i.e. 2 cups Airset, 2 cups sand, 1 cup hydrated lime, 1 cup cement). Mix
well while dry, before adding enough water to make a smooth, thick mixture. Take a small trowel of the mortar
and hold it upside down, it should stick to the trowel. The pot life of this mix is around 20 minutes.
Get all of your floor tiles soaking in water, and mix up some mortar. Only prepare one small area at a time,
enough to lay a single tile. If you try to mortar a large area it will dry out before you have a chance to lay the tiles.
Spread a layer approximately 10mm thick on the top of the heat bank. Use your fingers to notch this mortar
mixture, to bed your tile into.
We designed the layout of the CalSil board to be about 20mm larger than the floor tiles all the way around the
perimeter of the oven floor, so that there is some tolerance on the positioning of your floor tiles. The extra area
extending around the dome of the oven will be covered by the insulating blanket and render layers, while the
sections protruding under the front and sides of the oven floor can either be cut back using an angle grinder if
you’re installing a stainless wrap to the exposed edges, or left in place and covered when a landing is installed.
Reminder - you need to watch the instructional videos to get a full understanding of the process, please don’t
rely on these written instructions alone. Don’t feel like you need to watch them all at once - just watch the
section that you’re about to do before you do it, so that it’s fresh in your mind.
Laying the Floor Tiles