42" build in Central Texas

[GarnerAC]

Re: 42" build in Central Texas

Im currently at 37" to the top of my pedestal and was thinking a 43" oven floor. 3" of insulation plus a sandwiched Hardiboard 1" up from concrete is my current plan. Subject to change at any moment. I'll have to read that thread. 47" seems really high, especially while building it.

[texman]

Re: 42" build in Central Texas

GAC
It did add some challenge while building. I spent most of my build standing on the concrete base bent over to lay brick and climbing up and down up and down, up and down (you get the point). Actually, the higher base was better in the build because I did not need to bend as far to reach the floor since my feet were below the floor level.

I would measure the height of your elbows to feet in a comfortable stance and see what that is. Should be close to comfortable. Many folks do the phantom pizza peel and decide what is comfortable by feel and use that as their height. I am not trying to make a BIG deal about this, but once you start setting dome, you are committed.

Also, get that saw and brick as close as you can to you base-less steps.

Texman

[GarnerAC]

Re: 42" build in Central Texas

Decided a few things over Saturday. I mortared down 1/2 Hardi-Backer to give me perfectly level real estate. The concrete top had some 1/4" low spots due to the concrete slowly settling into the block voids. I would have done a better job with this had I had a helper that day. I think this will be good and give me another 3/4" height on my floor which will be 43" after going with 3" of FB insulation. I also laid out the Oven just for my own envisioning.

[jbruning]

Re: 42" build in Central Texas

Looking good! Although it is usually possible to correct issues as you go, starting out level (or plumb) is a much better approach. This should be beneficial. How consistent is your FB? I used 2 inch material and found some variations which needed to be dealt with.

[Kemo]

Re: 42" build in Central Texas

thanks for posting! I really like the hardi-backer idea. I will find this usefull on my next build which I hope to do sometime next year in Wimberley.

[GarnerAC]

Re: 42" build in Central Texas

Made some progress today. Drove up to N. Austin and picked up some bricks from Tom (Tscarborough) at MPI. Tom really knows his trade! Im using Boylantas floor layout because I liked his angled entry and arch layout.
I decided to set my dome on the floor. Just seems more structurally sound. The weight distribution on the rather soft Insulation board is spread more evenly. Ive got 4" of insulation underneath, so I cant imagine much, if any heat loss. Thanks Tom and Todd for the advice.
Any advice or critiquing is welcome.

[Tscarborough]

Re: 42" build in Central Texas

It looks like the insulation was fine without a leveling mortar. What you will find, when you begin mortaring the first course down is that the keystone brick will no longer fit. Instead of making it smaller, since it is already at the 1/4 unit limit, cut the 3 adjacent units to fill the gap when you come to it. That is to say, begin laying on both sides from the entry and then cut to fit the last three brick. Normally, it is better to pre-cut all but the last 2 or 3 brick, then cut to fit. They never work on a total course pre-cut (unless you are Les).

A pleasure to meet you today, it looks great!

edit-Unless you need the excess brick at the front outside of the oven for structural support of the chimney, I would trim them down some, but still no less than 1/4 of a full brick.

[UtahBeehiver]

Re: 42" build in Central Texas

GarnerAC,

Tscar gave me this exact same advice when I did my build. Dry fit never really fits once the mortaring starts. So it is really better to spread the adjustments over several bricks and avoid what Tom calls potato chip bricks. Everything is looking good. 4" of CaSi should make you golden. Good luck.

[GarnerAC]

Re: 42" build in Central Texas

Thanks for the tips so far. I only had to trim a 1/4" or so Tom. May have to work tomorrow so I slaved away today. I felt a little sloppy as I began but improved as I got the feel for it. Made a jig to cut 5 degree angles. A couple of vertical joints lined up , will keep them to a minimum from here on out (hard!) Wish the bricks had cleaner edges but I know, it probably doesnt matter in the end.
Questions:
The small voids in the backside bug me. Do i plug them with mortar now or wait till its all done?
Any advice on inner arch height? It's a 21" dome (I may drop it to 20"),with a 20" wide entry

[texman]

Re: 42" build in Central Texas

GAC
Good Looking start. You definitely want to watch the stagger. Cut 4-5 bricks at a time instead of the whole course and adjust to avoid the line up of the vertical joints. I would fill the voids at the back as you go.

If memory serves, you want an opening height of 60% of dome height. So 20" height is 12" opening. I would also get a clamp to use with your IT to hold the brick, very handy.

Texman

[deejayoh]

Re: 42" build in Central Texas

I used a jointing tool on the backs of my bricks. A good $5 spend for an amateur mason IMHO.

You should cover up the bottom of your oven before you get too far. You will have a lot of mortar dropping there + other stuff that will beat up the bricks.

[Tscarborough]

Re: 42" build in Central Texas

With a 20" dome height (I wouldn't go any higher than that, lower is fine), you need a 12.5-12.75 inner arch height. Keep it at 63% of the dome height and you are gold.

For the backside voids, fill in enough to stay in place, then use the ends of your batches to fill the rest. That way you never waste any mortar.

Looking good!

[kanoer54]

Re: 42" build in Central Texas

build looks nice so far.
ditto on covering the bottom of the oven to keep mortar droppings from sticking to the bottom of the oven. the higher you build, the more droppings and splatters seem to build. also, one thing i found, it is a lot easier to clean the dome interior as you go rather than waiting till you are almost done with the dome and don't have any light or air. it can get pretty claustrophobic in there and really hot!
jon

[Tscarborough]

Re: 42" build in Central Texas

Regarding droppings, if you just leave them alone until they are what is known as "fingerprint dry", they will come right off with no muss no fuss. When you mess with fresh mortar droppings or even on the joints, you just smear it around and make a mess. You should just leave excess mortar on the joints and the droppings alone until they dry enough that they are crumbly but not hard, in the range of 15-45 minutes depending upon the hydration of your mortar and the temperature.

[GarnerAC]

Re: 42" build in Central Texas

Got the 3 rows and floor all cleaned all up and covered w 2 layers of cardboard. Worked a little this afternoon, got a 3rd row done and got the arch supports ready. Im struggling with the arch angles. I guess i should have paid attention in Geometry class back in high school!
Finding that my diamond blade on a angle grinder is a very useful tool. It was almost 100 degrees today, a little tough to work with mortar. Went through about 5 spray bottles of water keeping things moist,

Whats the best way to cut the half-brick arch angles with a 10" saw?

No pics today. Maybe ill get some done tomorrow afternoon. The wife has been great, not a word about the latest backyard time and money consumer