New 40" build in Greenville, SC

[foxten]

Hey gang,

I'm going to document my build and hopefully get some tips and hopefully avoid some mistakes along the way with your help. I'm building a WFO in a porch addition as part of an overall outdoor living/kitchen area. The WFO is going to be adjacent to a wood burning fireplace and I'm going to be carrying the facade of the fireplace and the adjacent pizza oven all the way to the rafters. I want the face of the fireplace and the facade of the pizza oven above the hearth/dome to be on the same plane. I will be using versetta stone for my facade. I will be mounting OSB around the fireplace once it gets installed this Friday and from reading the eBook, I'll need to use steel studs above the hearth and then face it with hardibacker and then the versetta stone will be installed over the hardibacker. All that being said, what should my landing situation look like to make all of this happen? I'm sure I haven't given enough information, so please tell me what else you need to know. Thanks a lot!

[foxten]

OK. So I just made my template and cut all of the FB board and bricks to fit in the template. My problem is my FB board is not laying flat on the slab. Any tricks to get them to lay flat?

[MarkJerling]

There's a few tricks you could use. A wet slurry mix, or some tile grout springs to mind.

[david s]

A wet mix is so absorbent it goes hard as soon as it touches the insulation. A dry mix of 50/50 sand and powdered clay works far better. The same dry mix can be used between the insulating board and the floor bricks to get them perfectly level. It is an advantage for them to be loose laid so they can expand and contract freely

[foxten]

Awesome. So, here's my plan for the day

1) In my slab I should drill 4 half-inch weep holes underneath my fiber board
2) Put a mixture of sand and fireclay (is this what you mean by powdered clay?) on top of the slab
3) Put my fiberboard pieces down
4) Another 1/4" or so of the sand/fireclay mixture
5) Firebrick for the base of my hearth on top of sand/fireclay mixture

[david s]

Yes but glue some insect mesh over the holes so you don’t lose your sand/clay mix through them.

[foxten]

Alright. New problem!

I made a giant stupid error. I did all my templating based on an 8" long firebrick and my splits would be 4". It turns out it's 9" and my splits will be 4.5". My question is can I just reduce the diameter of my oven from 40" to 39" and use 4.5" splits or do I have to just cut two 4" sections out of each 9" brick?

[UtahBeehiver]

You can make the diameter any size you want.

[JRPizza]

You will be doing enough cutting on your dome bricks, I sure would not recommend reducing their thickness too. If you are building on your floor and don't want to re-cut those bricks a 39" oven is a great size (that is what I built). If your IT is done you will of course need to shorten it up by a half inch.

[foxten]

I went to the therapist today and I've been diagnosed with "arch anxiety". I'm at course #4/5 and everytime I read JRPizza or UtahBeehiver's posts after searching for "arch", I think I understand what to do, but then I walk outside and keep second guessing myself. Is there any chance somebody could do a 5 minute facetime with me and my arch to set me straight?

One issue I'm having is I don't understand how a pencil helps me. I also don't understand how all of the arch bricks look they have two perpendicular cuts to the vertical. How is that not a compound miter? Maybe the keystone brick would be two 90 degree cuts because it's straight up and down, but all of the arch bricks have an angle. Thanks guys!

[foxten]

Here are some photos that might help you guys see what I'm dealing with. I don't know how I would attach a pencil to my style of IT.

[JRPizza]

OK, deep breath....
Look at the first pic attached. The face of my IT bracket that the rod attaches to describes/defines the inner surface of the dome as it rotates around and pivots up and down. I placed the IT next to my TDC brick, laid a pencil so the lead was essentially at the same distance from the center as the back face of the bracket, and drew the line representing the inner surface by moving the IT up and down. No need to attach the pencil, just a little freehand. Then with a brick in the IT I eyeballed where the brick that will sit on top of the TDC brick would be, and drew a line not along the brick but starting at the ID and down a little to the right so I would have room to bed mortar when that brick is placed (make sense?). I then cut all my arch bricks with the same basic top angle once I figured out how long they needed to be. In the second picture you can see how I made the difficult cuts in the dome bricks as they mated up with the arch. As I approached the arch I cut the dome brick with the odd angle I needed to mate with the arch and used mortar as my friend, but first I sort of "transferred" the ID distance from that adjacent brick to the arch brick. All the cuts to the arch bricks were 90 degrees and I figured the slight ID mismatch was immaterial.
I hope this sort of helps and didn't confuse you more. Also others might have come up with more elegant ways to integrate the arch but you have to go with what makes sense to you and what you feel you can build. My method works if you build the arch as you build the dome - I don't know how anybody visualizes building the arch first but I think they probably just cut the dome bricks to match whatever they end up with.

[UtahBeehiver]

Here is pic from Mr. Chipster on a tapered inner arch similar to yours.

[foxten]

OK, deep breath....
Look at the first pic attached. The face of my IT bracket that the rod attaches to describes/defines the inner surface of the dome as it rotates around and pivots up and down. I placed the IT next to my TDC brick, laid a pencil so the lead was essentially at the same distance from the center as the back face of the bracket, and drew the line representing the inner surface by moving the IT up and down. No need to attach the pencil, just a little freehand. Then with a brick in the IT I eyeballed where the brick that will sit on top of the TDC brick would be, and drew a line not along the brick but starting at the ID and down a little to the right so I would have room to bed mortar when that brick is placed (make sense?). I then cut all my arch bricks with the same basic top angle once I figured out how long they needed to be. In the second picture you can see how I made the difficult cuts in the dome bricks as they mated up with the arch. As I approached the arch I cut the dome brick with the odd angle I needed to mate with the arch and used mortar as my friend, but first I sort of "transferred" the ID distance from that adjacent brick to the arch brick. All the cuts to the arch bricks were 90 degrees and I figured the slight ID mismatch was immaterial.
I hope this sort of helps and didn't confuse you more. Also others might have come up with more elegant ways to integrate the arch but you have to go with what makes sense to you and what you feel you can build. My method works if you build the arch as you build the dome - I don't know how anybody visualizes building the arch first but I think they probably just cut the dome bricks to match whatever they end up with.

I understand perfectly the part about marking the arc of the inner dome on the TDC brick. What I don't understand is how do you decide at what height to mark the top of that cut. Or what would be the bottom for the next brick above that. When you're forming the arc, you've got at least a couple of inches of up and down travel and I don't know when to make that mark.

Thanks for the responses!

[Kvanbael]

Here is something that took me a while to realize: About IT and pencil:

no matter at what weird angle you fix a pencil to your IT, ... as long as it is fixed, it will make circles with the pivot as center. So while tracing the inner dome cut lines on dry-stacked arch bricks, I would just hand-hold a pencil to my it, and regularly change position for easier drawing. I just had to check inner dome radius based on some reference points.