Hi All!
Got a question fer ya all. When installing the fire brick does one use morter or no morter?
Getting conflicting ideas from folks near me. Of course the veneer brick will have an airspace between the itself and the fire brick as well as being mortered. There is also a product that my Dad has bought that is more of a glue for fire brick. Not sure of the name of the product. I have asked my Dad to send me pictures of the site so all can see what I’m talking about.
Can fire brick be dry stacked and work?
Can it be mortered and what size of “grout” line?
What type of morter? is there a special type?
Replies
It's called Refractory cement.
You can dry stack a fire chamber but most prefer to make it solid.
Refractory cement has little to no tensile strength so the joint
line is kept to a minimum.
Two schools of thought on the subject (I don't have a favorite).
One is to mix it much like mortar and lay the firebricks as
usual.
The other is to mix the cement very thin and dip the bricks in
and stack the firebricks immediately. As in almost dry stacking them.
The idea is that the cement will always fail first so why make
a joint that is the Achilles heal of the structure?
I split the difference and mix the mud rather thin, and butter the
bricks as I lay them. To me this makes for a cleaner job (the faces don't have to be cleaned off as when you dip them) yet doesn't make
a large weak joint.
You can get Refractory cement almost anywhere. But if you choose to mix it thin you'll have to buy the dry as opposed to the premixed wet.
Chuck
The other option is to mix in some fire clay with the mortar -- helps the mortar move with the heat cycles without busting out. Doesn't take much -- about one shovel for every 5 or 6 shovels of sand.
Mike Hennessy
Pittsburgh, PA