32" build in Calgary, AB - pompeii neapolitan

[david s]

Although there have been many successful brick galleries built and traditionally it is the method used, a cast refractory or stainless gallery have more advantages, both in reducing thermal mass, structural integrity and being better to adapt to curves easily.

Brick units are not ideal because they have two big drawbacks. Firstly it adds a lot of thermal mass in an area where you don’t really need or want it. Secondly, brick units introduce instability. because of the many mortar joints, introducing weak points from thermal expansion and contraction.
Also an inverted arch as in the second drawing is inviting expansion rather than compression.
Anchor plates usually call for drilling holes and using fixings, both of which can lead to areas where cracks develop. Using an alternative method to fit or omit one is worth considering.

[IH123]

Although there have been many successful brick galleries built and traditionally it is the method used, a cast refractory or stainless gallery have more advantages, both in reducing thermal mass, structural integrity and being better to adapt to curves easily.

Brick units are not ideal because they have two big drawbacks. Firstly it adds a lot of thermal mass in an area where you don’t really need or want it. Secondly, brick units introduce instability. because of the many mortar joints, introducing weak points from thermal expansion and contraction.
Also an inverted arch as in the second drawing is inviting expansion rather than compression.
Anchor plates usually call for drilling holes and using fixings, both of which can lead to areas where cracks develop. Using an alternative method to fit or omit one is worth considering.

Thanks for the reply. however , I already purchased additional mortar and bricks to build the arch. I am avoiding castable refractory because casting isn't always better. A cast refractory must be allowed to dry and cure properly and I have no experience in that- thermal expansion still has to be accommodated with rigid cast tied tightly to refractory bricks tightly can crack too. I am looking to choose a brick arch. I am going for now, unless someone tells me about a better brick arch design, to abandon the inverted arch and use the regular known arch.