Decorative arch

[mfiore]

I'm about to resume enclosing my oven. I am planning a walled enclosure with cement board covered with some sort of stone veneer. Some questions have come up regarding the decorative arch.

I have a double arch fire brick entry in to the oven. I plan a decorative arch in front of this. Does this arch get mortared to the firebrick, or is there an expansion joint/gap of some type here?

The brick I plan to use should match my house brick, and is smaller in size than the firebrick. I also plan to drop the decorative arch about 1/2 inch below the firebrick arch, hopefully helping with smoke draw. As a result, the firebrick arch sticks up quite a bit higher than the decorative arch. I plan to put a hardiboard face on the enclosure. Can this board come close to or in contact with this firebrick arch?

Let me know if this doesn't make sense.

[Les]

Re: Decorative arch

I have a double arch fire brick entry in to the oven. I plan a decorative arch in front of this. Does this arch get mortared to the firebrick, or is there an expansion joint/gap of some type here?.

Mike, I mortared mine to the fire brick and I see no issues.

I plan to put a hardiboard face on the enclosure. Can this board come close to or in contact with this firebrick arch?

I don't know the heat properties of hardiboard, I would think that Durock would be safe since it is a concrete product. Is there a reason you are going with the board? I used it once and it was a bitch to cut and screw through.

Les...

[mfiore]

Re: Decorative arch

Mike, I mortared mine to the fire brick and I see no issues.

Did you use refractory mortar here? When can I transition to standard mortar?

Is there a reason you are going with the board?

Les...

Only the arch will be brick. The remainder of the enclosure will be block veneer. Because of the size differntial between the firebrick and house brick, much of the firebrick will not be covered by house brick. The board will need to cover the areas the house brick arch doesn't. The best example I can find is Christo's build.


Or Breven's

[Les]

Re: Decorative arch

I used standart type S mortar at that point. Looks like Christo used Durock

Les...

[exceloven]

Re: Decorative arch

I also used standard mortar with no problems. The 1/2" drop on the decorative arch is really important, maybe even 3/4". It has really kept the black off my exterior.

Mark

[smuth10]

Re: Decorative arch

Mike, this is exactly what I will be doing as well and I had the same questions. Thank you for posting this. They were questions I was going to ask down the road, but one less thing I need to sit up at night thinking about. I was worried about having to drop the outside arch down 1\2", but now I think I will just use the decorative stone to do this.

[mfiore]

Re: Decorative arch

For the inner arch, made of fire brick, many of us have cut tapers in the arch brick to create nice tight joints. I did this as well. I wasn't as worried about asthetics, since I knew it would be covered up.

I'd like a decorative brick arch in front. It seems there are two ways to proceed. 1) cut a taper in the brick so once placed in the arch, the mortar joints are uniform along the entire length of the brick, or 2) use uncut brick (or halves) and join together with triangular wedges of mortar, thinner on the inner side of the arch, thicker on the outer edge.

For large arches, spanning a window or larger structure, the second option would likely be fine, as the differences would be minimal. For small arches, such as in our WFO, does this make an awkward looking arch? What is the approach most have taken?

[Frances]

Re: Decorative arch

Here you go, two arches with the second method.

This is only because I don't own a wet saw which could make the required cuts, but luckily I also like the arches this way...

[bbell]

Re: Decorative arch

I went with the wider mortar joints for a couple of reasons. I wanted to keep some of the natural irregularities of the rocks and cutting the quartzite took forever. I actually sliced the rocks into pairs for the arch and only made an edge cut for where stones aligned with the opening.

[dbhansen]

Re: Decorative arch

Mike, a while back I did some checking on the fire resistance of Durock vs. Hardiebacker, and someone in another forum took a torch to some hardiebacker and made it red hot. It never caught on fire or lost strength. I think we're good with putting it against the firebrick (my plan too), although I'm not sure how the stucco or other outer coating will react to the heat. Could you put a layer of fiber insulation or slices of insulation board between the firebrick and hardiebacker?

If I had thought about it sooner, I might have placed my metal stud wall even with the front of my outer firebrick arch, instead of setting it back 3/8". That way I could use 2 layers of hardiebacker on the front. The first layer would go around the firebrick, and then I could put a layer of insulation over the firebrick and cover the whole thing with the outer layer of board. As it stands now, I think I'd need 3 layers of board to do that. Just a thought....

Good questions, by the way!

[Massimilliano]

Re: Decorative arch

ciao Frances
I loved the multi-coloured artwork oven.. Any chance you could provide some detail of how you did the vent and the chimney,
This is an area I am struggling to get my head around as I want5 to use an 8" chimney yet minimise the size of the front arch..
Grazie
Max