What material do you use for the roof of a masonry firebox?

[Stigwort]

Hi!

Any advice much appreciated. What material do you use for the roof of a masonry firebox?

The discussion and comments here: http://www.livingstonemasons.com/ins...door-fireplace seem to indicate that you can just use cement for the firebox roof.

If regular cement is used for the roof, not refractory cement, should the cement be painted with high-temperature paint such as Rutland or AW Perkins?

Thanks!

p.s. The bottom and sides of the firebox would be fire brick with refractory mortar. It is the roof of the firebox that I am concerned with. I am referring to the ceiling (the gray, curved, top of the firebox) of the firebox, and I have attached a picture. Any help appreciated!

 

[webby3650]

Is that a picture of a pizza oven? A fireplace wouldn't have a ceiling.

 

[bholler]

Regular concrete wont hold up long

 

[Stigwort]

Is that a picture of a pizza oven? A fireplace wouldn't have a ceiling.

It is an outdoor wood burning fireplace. Is it functional for that purpose?

 

[Stigwort]

Regular concrete wont hold up long

Anything I can do to salvage it? Will the paint make a difference?

 

[bholler]

Anything I can do to salvage it? Will the paint make a difference?

You could arch firebrick if you build a form to support it while you build. And no the paint wont do anything. But honestly for it to work right you are going to have to build a smoke chamber that tapers down to the size of your liner

 

[Stigwort]

Many thanks for taking the time to respond. So I did some research. Do you think that this will work on the firebox ceiling? Heat Shield Chamber Coat: Use Chamber Coat for hand-parging or trowel-on applications or where smoke chamber is easily accessible. http://heatshieldchimney.com/smoke-chamber-repair/

 

[bholler]

Yes it would hold up to the heat. But it is not structural so if that ceiling is supporting any structure you would nee concrete then cover it with chamber coat or chamber tech. But again if you go with a flat ceiling like that instead of a smoke chamber allot of smoke spillage is very likely.

 

[Stigwort]

Thanks, HBoller. The ceiling is curved and very thick and is concrete. Too late for a smoke chamber. Obviously, I regret that, but we will see how bad the smoke is :-(.

So I guess I will cover the firebox ceiling with chamber coat and see how it goes.

Yes it would hold up to the heat. But it is not structural so if that ceiling is supporting any structure you would nee concrete then cover it with chamber coat or chamber tech. But again if you go with a flat ceiling like that instead of a smoke chamber allot of smoke spillage is very likely.