Concrete mix ratio different when Heated
I have a 30″x40″deep electric ceramic kiln. I’m building a wooden framed shed with a concrete slab floor in which this high temp. kiln will be operated. Shed wall thickness is 6″.
To offset the heat, I plan to use unfaced fiberglass between the wall studs and Hardiboard vertical siding over sheetrock that has a homemade foil faced radiant barrier bonded to it. The kiln will sit an a corner so the two walls will be covered 4′ from the corner as will the 8′ ceiling.
After completing the insulation, sheetrock, and Hardiboard, I’m thinking about pouring in the corner, two 4″x 48″wide x48″ high vertical concrete walls with rebar anchored in holes drilled into the slab and fuctions as an additional high heat barrier.
Will 4″ be thick enough? Should there be a special mix to handle the extended exposure to high heat other than the expensive refactory cement used in wood stoves?
Thanks for your help,
Bill
Edited 3/22/2008 10:31 pm ET by BilljustBill
Replies
I don't quite understand your question.
Will the walls be part of kiln? if so then you need to use
soft fire brick and adhere to the necessary fire codes. Four inches of fire brick and something like 24" clearance to nearest wall etc.
If theses walls are just a sort of hearth of sorts then check the
kiln manufacturers specs.
Most of the time there is just a minimum clearance to walls, much like a wood stove. After necessary clearance, then you needn't worry about
extra fire proofing. In fact creating extra thermal mass could be questionable over a long firing period.
Henley,
The kiln is a selfstanding, 8-sided and jacketed in stainless steel. The wall is just an added barrier between the kiln and the wooden stud framework.
Thanks,
Bill
Might help if we knew what your intentions were. Is this in a cold climate? Protecting from weather etc.
MikeInsert initially amusing but ultimately annoying catch phrase here.
This is an electric ceramic kiln for firing ceramic pieces. In North Central Texas it gets cold and hot....
You see, if I can move out this electric kiln from an 8'x15' room inside my workshop, I can turn that empty room into a dustfree finish room.... To do so, I've been building a 16'x32', two story hobby room and shed for my wife. I just don't want to burn it down.... :>)
Bill
Is there some reason you can't have the required clearance? If not, then there's no need. If so, then I'd be hesitant to venture an opinion. That said, leave proper clearance. Then normal concrete is
Fine. Then one inch air gap. Again without the clearance count me out.
I see no reason for the added wall.
What clearance does the kiln manufacturer recommend?
To protect the walls and not add mass that will hold heat in the building during the summer months.
I would place a radiant barrier set off the floor by several inches, and off the wall by the same amount.
The barrier only has to be a foot or so taller than your kiln.
It will reflect the radiant energy back into the room , and the air space behind it will function as a chimney to keep the barrier itself cool and thus protect the wall behind it.