Supporting the rock facade

[Harpist]

Hi folks,

I have a question for any of the experienced masons on the forum.

I will be using 2" wall caps to build counter tops around the oven dome. But I won't have time to install the counter-tops before winter hits (since I need to finish the BBQ grill foundations and this won't happen until next spring). But I want to finish the rock facade on the outside of the oven enclosure (I have enclosed the dome with steel studs and backer board).

For the facade I am using 3" wide ledgestones that I have been gathering in the hills of North Idaho. My plan was to install 2 1/2" angle iron at the base of the enclosure to support the facade (I plan to put temporary spacers under the angle iron where the wall caps will eventually fit).

Does anyone see a problem with this? I assume I need to use steel and not aluminum (although aluminum would be easier to work). Any recommendations would be welcome.

Good Roads

Harpist

[Tscarborough]

Re: Supporting the rock facade

Need more info, esp. pics. As a rule, angle iron can be used to support masonry, but it is always an engineered solution. Post some info and pics, and I think I can help some.

[Harpist]

Re: Supporting the rock facade

Need more info, esp. pics. As a rule, angle iron can be used to support masonry, but it is always an engineered solution. Post some info and pics, and I think I can help some.

Hi Tscarborough,

Here are some pictures:

Photo 1 - Here is an enclosed oven dome

Photo 2 - Angle iron is placed at the base. This angle iron in the picture is only 1" (all I had on hand) instead of 2 1/2" that I plan to use. This would be screwed into the steel stud enclosure frame and temporary spacers would be underneath the angle iron.

Photo 3 - This autumn, stones would be stacked on top of the angle iron and mortared into place

Photo 4 - Next spring, the temporary spacers would be removed and the counter top (probably 2" natural stone wall caps) would be used to insert under the angle iron and cover the horizontal surface (I just put the two flagstone pieces in the photo to simulate the wall caps).

I know this is not ideal - better to build from the bottom up. But time is limited before winter hits and I want to get the oven dome weather proof (and usable).

Thanks for your input!

Good Roads

Harpist

[Tscarborough]

Re: Supporting the rock facade

I would not use the angle iron. Better to go ahead and set the pavers that will fall under the wall and lay directly on them.

[Harpist]

Re: Supporting the rock facade

I would not use the angle iron. Better to go ahead and set the pavers that will fall under the wall and lay directly on them.

Tscarborough,

I appreciate your input. Can you give me some idea about the trouble I might be getting myself into by using the angle iron?

If this was mid summer, I would lay the pavers first. But the pavers will eventually extend over - not just the horizontal surface around the oven - but also over a the horizantal surface of a grill on the left of the oven and and a prep area on the right of the oven (the pizza oven is in the corner what will eventually be an outdoor kitchen).

So to lay the pavers, I need to first get the foundations in for the grill and the prep area. With 4-6 weeks before snow starts, I don't have time for the this.

Thus the reason for the use of angle iron. Basically, this would allow me to get the oven closed up for the winter. But I won't do this if I risk the integrity of the stone facade.

Again, thanks for your responses.

Good Roads

Harpist

[brickie in oz]

Re: Supporting the rock facade

If your floor slab extends to the outside Id me more concerned about heat loss seeping away to the outside, the hearth will never get hot enough from the loss of heat.

[Harpist]

Re: Supporting the rock facade

Brickie,

The top layer of the slab shown in the picture is the vermiculite layer so I can't see how having it extend outside the dome area would be a problem (except for water wicking). For heat to seep away out of the dome and horizontally through the slab, it would be going through 8 - 12 inches of vermiculite concrete.

The vertical heat loss will be much greater under the dome where there is just 3 1/2 inches of vermiculite before the underlying conventional concrete slab.

I am presently going through the cure cycle. Once I get an extended firing period, I look forward to profiling the heat losses

Good Roads

Harpist

[Tscarborough]

Re: Supporting the rock facade

I meant lay just the pavers that will be under the stone, not all of them. The first issue with the angle iron is that you have nothing strong enough to bolt it to; steel studs and backer-board won't do.

If it were me, I would cut pavers into strips the width of the stone or a tad more, and then use them for the first course (so that there will be a consistent outer surface). You then just butt the pavers to the wall when you get around to it.

Technically, you should have left a brick ledge to do the same thing and to provide a flashing point. As it is, you should flash over the first course and weep the second one.

[Harpist]

Re: Supporting the rock facade

Tscarborough,

Thanks for the clarification. I think I can do this although I need to think about the backside where I ended up with a ledge that is too small (until I get the stone facade done on the hearth underneath).

Thanks again

Harpist

[Tscarborough]

Re: Supporting the rock facade

You CAN bolt an angle to the slab on the part where you will extend the stone from the ground.

[Harpist]

Re: Supporting the rock facade

You CAN bolt an angle to the slab on the part where you will extend the stone from the ground.

Hi Tscarborough,

I was sitting staring at the oven and mulling the possibilities when Mrs. Harpist made the final decision. She suggested (i.e. told me) to tarp the enclosure come winter and spend the remaining time this autumn building the structure for a sitting bar to go along with the sink and cooler.

This was the first I had heard about a bar - but who am I to argue with a great idea (anyway if mama isn't happy, no one is happy). So no pavers or angle iron this fall. I'm sketching out a design (as I watch Dallas and Washington square off) and will go buy the cement blocks and rebar tomorrow.

Thanks for your input. You slowed me down long enough for new ideas to take hold.

Good Roads

Harpist

[Tscarborough]

Re: Supporting the rock facade

I have always been of the opinion that there is no need to settle for a sub-optimal outcome if the only criteria is time.

Your wife is a smart woman.

[brickie in oz]

Re: Supporting the rock facade

Brickie,

The top layer of the slab shown in the picture is the vermiculite layer

Isnt the vermiculite supposed to go underneath the concrete slab as the concrete slab then acts as a heat bank to store all your heat?

[dmun]

Re: Supporting the rock facade

Isnt the vermiculite supposed to go underneath the concrete slab as the concrete slab then acts as a heat bank to store all your heat?

Whoa! No! That has approach has been discredited by trial and error. If you want to cook pizza, you want insulation right under your brick. You have to burn forests of wood to get your oven to temperature, and it's really hard to get balance between floor and dome with that huge heat sink.

The only situation where you want additional thermal mass is in a commercial bakery, where you're baking batch after batch of bread, and firing every day. Even then, you need to thermally isolate your entire oven envelope except for the opening.