Treehouse Pizza

[david s]

Many factors involved.
Type of brick used. High, medium or low duty.
Size of brick. The larger they are the more vulnerable.
Amount of use they get. Commercial ovens used daily are more vulnerable.
Rate of temperature increase and decrease. A slow rise is far safer.
Maximum temperature reached.
Only the bricks in the floor centre seem to suffer.

[RandyJ]

Well we were very busy today but I managed to get a little bit of work done this evening. I got a bit more then half the floor tiles in place and started getting rid of the forms from the concrete work.

Randy

[RandyJ]

I managed to get some more work done this afternoon. First I found out about friends friends that was trying to get rid of some oak logs so of course I ran straight over and grabbed 2 full truck loads of loads and brought them home and neatly stacked the driveway. My neighbors going to try to get his friends splitter to split it all.

After that I mixed up a few more batches of mortar and finished setting the floor tiles. I had hoped to do that yesterday but with all the mothers day stuff going on I didn't have time or energy. I smoked a 16# brisket for my mother in law and that ate most of my spare time yesterday. Tomorrow I am hoping to start laying the dome bricks. It will be interesting to see how that goes. Wish me luck.

Randy

[RandyJ]

I managed to get some more work done on the oven this afternoon. I started by getting the layout nailed down and drawing the layout lines. This is not hard just a bit time consuming to make sure everything is correct and in place.

Once that was all completed I started soaking the bricks and mixed my first batch of mortar up. I started with the door arch and vent bricks. I think I may have had the mortar a bit wet but it worked out just fine. Once those were done I set to work on the first course of bricks. I got a bit more than half way around. I think the hardest thing is going to be getting the mix on the mortar correct so it is not to wet and not to dry either. Beyond that this feels like a giant lego set. If I had a full weekend I think I could knock off a major portion of the build in just a few days. As it is we have some kind of forman training tomorrow and I am really hoping for a half day on that so I can get after this some more tomorrow.

Randy

[RandyJ]

I got home a bit early today because of the training that I went to today. I managed to finish the first layer and then also completed the 2nd layer. I am torn trying to decide I'm I am making good progress or if this is taking longer than it should? My wife was like well how long is this going to take? I am trying to go fast but also try to keep a fair bit of quality too. I am not going for perfect because the time line goes up exponentially very quickly past here. I also covered the oven today as it is supposed to rain tonight. Not sure if I will be able to get anything done tomorrow as we have a trainer coming for our dog Peanut and my son has his ninja class. So I am guessing that I am not going to make any progress tomorrow. I also covered the oven tonight as it is supposed to rain. Not sure how much it would matter at this point because I have been stacking soaked brick and spreading water on the flat surfaces.

Randy

[Giovanni Rossi]

Randy, getting the consistency correct on the various cementitious products in the kit was one of my challenges. I wrote it off to inexperience. One comment on the speed of your build and your timeline. I went great guns on the first 4 rows and thought that it was going to be a piece of cake to finish. Then...row 5! Take a quick look at my build starting at post #47.

[RandyJ]

Hey Giovanni Rossi I just went back and reread that part. The slippage of bricks is something that concerns me. Maybe I am putting to much water in but this mortar doesn't seem as sticky as the home brew i made for the last oven. I am having thoughts of switching to that as it was stickier. I never had issues on the last oven even at almost the final row. I never used supports from what I remember and nothing moved.

So just as a question how long did your build take? This is where I was on my last oven at this point in time and it was ready by the 4th of July more or less so I am hoping I can make my deadline.

Randy

[Giovanni Rossi]

Randy, Had to check my journal.

Started the bricks Oct 5
Had the problem on Row 5 on Oct 11 - 30 hrs at this point
Finished Row 8 Oct 24 - 65 hrs total at this point If you are planning to cast the keystone, that's all you would have left at this point.
I used brick the rest of the way and laid the keystone Nov 1 - 95 hrs total

No question having to prop each brick slowed me down. Plus, I was using an angle grinder to cut the bricks. And, most importantly, I just don't work that quickly. Masonry is not my strong suit. After row 3, I got into a routine of measuring out amounts of dry mix that would allow me to lay 5 full bricks at a time. I found the mortar would set too quickly if I tried to do more than that. So, there was a lot of time spent stopping and cleaning my mixing containers. Also, the daily temps were starting to drop, so that probably retarded the curing process a bit.

And, I'm retired and had no urgency other than wanting to get some insulation on and make some small fires to dry things out a bit before the first hard freeze.

Maybe Ben can give you some ideas about the mortar. He didn't seem to have a problem in his video. However, I believe they have changed mortars since that video was shot.

Hope this helps.

[RandyJ]

I am almost 100%positive that they have changed mortar since they made the videos. The color is completely different from what I have to what they show. I called Smith-sharpe fire brick supply and the have fire clay in stock for 19$ for a 50 # bag. I will continue to play with the supplied mortar but if I am not having good luck with it I will just switch to home brew. I know that works well .

What is the recipe for that again? I feel like it was 1,1,1,3 fire clay,Portland cement, hydrated lime, sand. Does that sound about right?

I have not been keeping exact time on this build so far . I was thinking of it but well i forgot to. I would guess i had 3 to 4hr doing the insulation and heat bank, 4or 5 hr doing the floor tiles and about 7hr on the dome so far. So ballpark 16hr so far. And probably about the same or a little more for the base. From my past experience I feel like this was the hardest part of just getting started and then everything just went together. . I am unsure if I will go all the way in brick or pour the key stone as is suggested. The castable didn't set very fast for me and I was kind of frustrated with it. I may have made it to wet and it dropped from the mid 60s' to about 40 that night so I am sure that didn't help.

Randy

[Giovanni Rossi]

I didn't use it , but the experienced builders on the Forum use:

3 parts sand
1 part Portland cement
1 part hydrated lime
1 part powdered clay

I recall david s recommending silica sand vs. river sand bc it has sharper granules. I just can't remember if that pertained to casting vs mortar. I'm sure he'll see this and clarify.

[david s]

You should follow the manufacturers recommendations. The 3;1;1;1 mix is designed to work for a range of temperatures. If the Portland fails ( beginning north of 300C) then the lime takes over. Should the lime fail (beginning north of 500C) then the clay takes over. As our temperatures don’t ever reach the 573C where clay sintering begins, the clay’s function is only to provide extra stickiness. This is a useful quality particularly when asking bricks on the higher courses to remain is place after laying. Unfortunately clay has the disadvantage vantage of imparting shrinkage. For this reason I halve the clay content in the mix. Research papers say clay can increase a mortar’s strength up to 7%, but higher than that begins to weaken it. Many sands already have a slight clay content. Sometimes bricklayers will add a little clay to those without it to improve the stickiness of the mix, although a mortar plasticiser these days is the preferred alternative. Silica sands are generally free of clay and have sharper grains which may be a slight advantage. I always dry and sieve my sand to remove any larger grains that can be problematic in mortars. A mix of grain size is desirable for a castable or render as it can enhance strength..

[RandyJ]

I got about 3.5 hrs of work in this afternoon. I have the vent up to as high as it goes . I also completed the 3rd row and had a little mortar left so I placed the first brick on the 4th row. I am hoping to be able to get a good stretch of time to work on the oven again tomorrow. In a ideal world i would like to get the 4th and 5th row complete tomorrow and maybe the vent arch. Depending on what all comes up tomorrow i may be able to complete that.

I am very happy to be done with the base and doing the fun part of the build. I am very happy with the results so far. I am so happy to not have to cut the brick this time. I enjoy doing the putzy type of work like this. At work I am happiest when I get to be left alone and allowed to bend pipe how I want and pick the route I want. This feels a lot like that for me. I can just zone out and go to town. I will probably be a bit sad when I finish the brick work, but then I will be that much closer to getting to cook with it.

Randy

[Toiletman]

You're making great progress! a week ago we were at the same stage, but I think you're speeding ahead now, but it's not a race ofcourse. Advantages of having a kit and a previous WFO under your belt I guess. My money's on you winning the 'race', I'm now busy creating the inner arch mold and then it's back to cutting stones.
But fully agree with you that this stage is the most fun: it really starts to look and feel more like an oven and you get immediate results from every hour you put in.
You talk about bending pipes and choosing routes? Are you doing oil & gas utility installations or something? Or in another line of business? I'm in semicon, currently working on software for creating P&ID's. I guess those are the ones you turn into isometric drawings before you start bending?

[RandyJ]

Hey Toiletman , I am a Commercial / Industrial Electrician by trade. I like to try to stay on the industrial side of things doing rigid pipe installation and control work. I want nothing to do with residential work and try to stay away from most commercial stuff too if I can. As far as routing I do not like to draw things our I can just see where I want to goand usually can tell if it will work just by looking. I hate when we get preplanned cad drawings as it almost never fits where they say.

I will have to go find your build and take a look. part of why i even started this project is because i am working close to home currently. I am only like 2 miles from home and normally I am 20 to 65 miles from home. So i have some extre time so i am just trying to hammer this out quickly before I have to go to a different job site or wind up doing overtime. I also tend to get a bit obsessed with projects and have a one track mind on these things. I also have to admit the kit makes this super easy combine that with having built one before and it is a recipe for flying through the build. I only started digging like 3ish weeks ago. And got the kit just over a week ago.

This is some of the pipes I ran. This is 3 x 3.5" rigid conduits and 2 x 3" this was a fun project and this was just the prep work and we went in on Thanksgiving to finish the run and pull the wire in.

Randy

[UtahBeehiver]

Always appreciate good "trade" work!