42" In South GA

[Neil.B]

In all the builds i had seen on here I assumed the uncut brick edge was placed on the inside, by your wording they are placed outwards, is that correct?

I mentioned inward and outward facing as there may be occasions where a brick needs to be cut to save wastage, in which case the cut edge can be faced inwards but ideally above the arch where they won't be seen.

I should of said if using a hammer to break, then face the rough face outwards. To save blade usage and time I cut quite a few of mine on one side then turned the brick over and hit with a hammer and faced outwards.

My bricks are 12"*6"*3" so I cut them in to six (4"*3"*3") , my dome is 4" thick. You can see after the second firing where the cut bricks are faced inwards. It's no big deal to me that they look rougher as it made it very cheap to build.

[SableSprings]

Normally the cut edge is faced out and will be covered with insulation.
My bricks are larger than normal and cut in to six, so I have cut and uncut facing inwards.
it's easier to clean off mortar from a smooth brick, so worth trying to get as many smooth sides inwards as possible, or rough sides above the arch where they won't be seen.

To save on cutting blade, you can just cut part way through your brick then hit with a hammer to break (if your cut is facing outwards).

Neil, I'm a little confused by your advice here. In the first part you say to place the cut edge facing out, then later mention "as many smooth sides inward as possible". I would always recommend putting the smoothest/cleanest side facing in, which is most often the cut side. For most firebricks that have damage, it is on the end corners & edges. When you cut a brick in half to use in the dome build, the edges are more reliably "square" and the face smooth. That is also the reason, I wouldn't recommend using the hammer break method all the time...it often creates a rough section where the brick is broken. If your firebrick ends are pristine, the hammer break method works because the hammered () rougher side WILL be placed facing out, as the manufactured end is the best face. I suspect this is what you meant...but just wanted to clarify it (at least for me...).

Neil, interesting that your firebricks are being cut into six pieces...that's a big original brick!

[Neil.B]

Normally the cut edge is faced out and will be covered with insulation.
My bricks are larger than normal and cut in to six, so I have cut and uncut facing inwards.
it's easier to clean off mortar from a smooth brick, so worth trying to get as many smooth sides inwards as possible, or rough sides above the arch where they won't be seen.

To save on cutting blade, you can just cut part way through your brick then hit with a hammer to break (if your cut is facing outwards).

[edonovan]

Thanks Mongo,
So would I leave the discrepancy in bricks towards the exterior of the dome? I think it is just material lost with the blade cut.
I feel the same on the 2x 2” so that confirms that.
and glossy cut brick sounds like what I’m looking at
lets try this picture thing again...

[mongota]

None of your attached photos show up for me. I just see three 'missing photo' icons.

1) 4.5" vs 4.375", no worries.
2) I'd prefer two 2" thicknesses with offset seams versus a single 4" thickness with full thickness seams. I'd not be worried about the potential of the insulation losing its water resistance. Plus you're building this under cover. If you ever had some sort of significant wetting catastrophe, a long slow several day fire will dry everything out. Your dome, and how well it clears down low to the floor, will let you know if your floor insulation is holding any moisture.
3) Firebricks are more dense and therefore heavier than an equal sized pressed brick. A typical 9" x 4-1/2" firebrick will weigh 7-8lbs, a pressed brick of the same size will be a couple of pounds lighter. When you cut a firebrick the cut face will usually be glassy smooth, and there may be 'freckles' or small dots/spots within the cut surface. A cut pressed brick will typically have a slightly rougher sandpaper type of texture versus the glassier surface of a cut firebrick.

Hope that helps, looking forward to following your build.

[edonovan]

I keep repeating these little tips over and over in my head "about starting today" and especially how these were built with a quarter of the "tools" and supplies that we have today and they work just fine...we are just "perfectionists"... So the more that I repeat those the more I get motivated to get this going...
Made a "footprint" template today, to get an idea of how far out to go with my Cal Si and where to make my weep holes. Made my IT, but after reading 36" Pompeii in St Louis (@plastered) the swivel caster can cause you to adjust more than one might want to.
As always...a couple questions.
1) Trying to save a wee bit on budget I am attempting to do the diamond blade in a chop saw route and soak the brick. What happened is what you see... 1 brick is 4.5 and the other 4 3/8. Any insight on this and is this a major problem?
2) Getting quotes on my Cal Si and am getting the Thermo 1200, which after speaking with someone at Johns Manville the "water resistant" additive will loose its effectiveness at 450 degrees. So that being said...would the bottom of the Cal Si really get 450? Thinking that it needs to go through the fire brick and through the entire thickness of the Cal Si I wouldn't think so. Also, they make this in several thicknesses and wondering if there is any advantage to doing 2x 2" as opposed to a 4" block. The rep at JM stated that it may allow me to stagger my seams and reduce heat loss going with the 2x 2". Opinions? or am I just over thinking this like probably every other aspect of this project and either will be just fine... LOL
3) Last....for this segment of questions (ha ha)....this is just my craziness of my head...is there a way to "test" my fire brick? Like I said previously, my firebrick is a little "off" on the standard measurements, so just would hate to build a WFO and these brick not be firebrick. (they look like firebrick).

Thank you FB Fam!

[mongota]

Anyone know if this half pallet of bricks is ok to leave in the elements with a tarp over it? or should I re-stack in on a pallet in the back garage?

I'd recommend you stack the pallet once, near your build site. Close enough to be 'close', but not so close you're tripping over it. You can tarp it or leave it uncovered during your build. As you build you'll likely want to soak the brick in water prior to mortaring them up, water exposure won't hurt them. I'd tarp the pallet if leaving it over the winter.

If that brick count is just for the dome, extra brick will be handy for your vent arch and chimney transition.

I hope you enjoy your build!

Best, Mongo

[edonovan]

Thanks Barry.
I just picked up 230 bricks and after doing some measuring, I am might be about 20-30 brick shy, but will probably need to head back down that way one day for more materials. I was unsuccessful at locating medium duty fire brick within a 2-3 hour radius, but found light duty brick 1 hour away. It still says it is rated at 2000 degrees...that being said it measures 9 x 4 x 2 1/8. Not a huge difference in "standard" fire brick, but hopefully wont run into any issues down the road. Anyone know if this half pallet of bricks is ok to leave in the elements with a tarp over it? or should I re-stack in on a pallet in the back garage?

[Baza]

I ordered 210
I'm nearly done the dome - set aside what I think I will need for the vent opening and I have 10 full bricks left.
I think I'll just make it - then again - I'm a newbie and others may be more careful in their approaches and used less.
Good luck! You can always get more!
Barry

[edonovan]

another question...sorry...I am really try to "force" myself to get this going and and the very least get supplies to the house as we live semi-rurally. Using Deejays dome spreadsheet and doing a 42" WFO it suggests that I roughly need 214 brick. is this fairly accurate? Is there a standard percentage of "extra" that I should grab...maybe round up to 250? or more? Thanks for all the help so far.

[edonovan]

more info I just got emailed...The Super Firetemp board is a 20# PCF and the calcium silicate is 15# PCF. I understand that is density, but are those "standard"?

[Gulf]

Probably overkill. But, I will let Russell look at it. The scoring just sort of jumped off the page at me lol.

[edonovan]

Thanks Gulf , I saw those on the sheet and definitely questioned them, it looks like they have a flat block option...just questioning if either one is better? My understanding is the Thermo1200 is waterproof and the Fire Temp is not, but rated for 2000 degrees (is this overkill?) Obviously pricing will play a role, but I am leaning towards the waterproof. The rep also stated that the Fire Temp is much denser product, so I also want to make sure that I can cut to shape.

[Gulf]

Don't order the "scored" boards. They are designed to be fit around large diameter pipe. Laying flat on a hearth, the scores will leave uninsulated voids.

[edonovan]

Anyone can give me insight between these two CalSi...One better than the other? Is 1 overkill?