Under way in Socal

[WJW]

Re: Under way in Socal

For what it's worth on the gap between floor and walls...I did not leave a gap near the back wall and I have no doubt that's what caused the crak in the pic below...



Doesn't affect performance or structural stability because behind the bricks are four inches of insblock 19 ridgid insulation and eight inches of block and rebar...nowhere for anything to go, but I'd certainly prefer that it weren't there.

[cnicholson]

Re: Under way in Socal

Thanks Dino...now I just have to be militant about sticking to my goal! It's kinda hard when I have ZERO idea of how long this is really going to take. It's like everything else that gets broken down into pieces...you don't realize how many pieces your actually putting together.

I'm still scrubbing through threads to get ideas on the best way to do a thermal break and exactly where. After looking at what seems like 100 threads I've almost come to the conclusion that:

1. If you screw up the break by design or execution, you run the risk of having a seive of sorts for heat loss.

2. The vent landing floor is part of the oven floor in almost every build I have seen. I would think that this would be the biggest potential source for heat loss and everyone's oven seems to be holding heat.

3. The extra thermal mass in the vent arches is not that big of a deal as long as you have an outer arch and chimney brick with at least an airspace between, if not insulation.

Heck, I'm still trying to wrap my head around how to cut the bricks at the entry vent so I'm almost outthinking my own build...crazy....

Thanks again for all the help!

[Dino_Pizza]

Re: Under way in Socal

1st: Congrats on finally getting the oven started with a real completion date.

2nd: (if it's not too late) YES, a GOOD 1/4" is important. I mean, I've not gone into my dome with a micrometer but I just know there is that much expansion and since you appear to be leaning toward a reall soldier coarse (on-end brick surrounding the floor) use the double corrugated cardboard strips to get your 1/4" spacing from the herringbone floor.

Glade you are going with a flaired entry, for the tiny bit more work, you'll be glad you did.

Also, if I had it to do all over again, I would have taken the time to put in an expansion joint like John did, (to isolate the oven from the inner arch and vent box) but it will slow you down to stop and think and do some designing. I get the same way about having a thermocupler in the brick to temp the saturation. But, I don't have them and love the wfo just the same .

Lot's of luck and have fun building it.
-Dino

[cnicholson]

Re: Under way in Socal

I was trolling it IT sticky and Chipster brought up an excellent point with not using a soldier course. He said he sometimes gets his peel stuck in the joint at the floor/dome... So in my case I decided to go out and buy full height bricks, lay the subfloor with splits and put the full height starter on that and go up from there...I'll post it up when I start (hopefully this week!).

[cnicholson]

Re: Under way in Socal

Thanks for all the replies so far! I am laying out my second layer of floor bricks right now and I am leaving a 1/4" gap on the sides for expansion.

A couple of things are coming to mind at this moment:

1. Laying two layers of bricks is presenting me with some unevenness in the last layer. Would the fireclay/sand leveling mix for the first layer work in between as well? I'm assuming that the sand/fireclay mix is essentially just adding more thermal mass (albiet 1/16" thick). My concern is that that leveling layer wouldn't distribute the heat to the bottom layer.

2. I laid out my opening 20" from the OUTSIDE of the dome and it flares to 25". Now when I bring that line to the INSIDE of the dome it necks down..I've already cut one side of the opening so my thought is to just bring the brick straight out for the thickness of the dome and then start the flare. Just to verify though, I want to place the door reveal at the OUTSIDE of the dome?

Thanks again.

[UtahBeehiver]

Re: Under way in Socal

Hi C,

I put a band of cardboard between my floor and sailor course then after the first course I masked of with tape to keep mortar out too. I got the idea from other WFOers. Attached is a pic, if you look hard you can see the cardboard. I am told it eventually burns out and then fills with ash.

[GianniFocaccia]

Re: Under way in Socal

Don 't have access to the FB plans at the moment, but the conventional design has the entry bricks match the level of the floor so you can slide pans in and out smoothly. I know some builders have the entry floor a step down from the oven floor, too.

Regarding floor brick expansion, I'm not sure. I do know that if the gap isn't big enough (or there is some errant mortar accidentally left in the gap) an expanding floor can press up against the dome with enough pressure to make it crack.

3/8" would work well I think, but I would definitely go more than 1/8". The gap will quickly fill with ash and you'll never see it.

[cnicholson]

Re: Under way in Socal

Ok...after some sleep, and a little review on the basics, I think I got this. On page 39, pic 7.6, it shows what I think is correct brick placement at the entry, aside from flaring and a door reveal?

Also John 1/4" gap around the entire circumference seems like a lot? Do the floor and dome really expand/contract that much and at a different rate? Thanks again!

[cnicholson]

Re: Under way in Socal

Thanks again John!

The sailor course would be basically a 5-7, 1/2 brick vertical course to give the Neopolitan feel. I don't intend to do any historically accurate work here, I just like the flatter dome look and, I think it was you actually, posted a pic of an ancient Pompeii oven I have actually been obsessed with!

So, I have rigged an offset, adjustable IT and mounted it to a false brick of 3/4" ply that I can interchange with a split in the floor for height. I then centered a brick on a herringbone pattern, off of the center of the floor, on which all of the dynamics (layout, IT movement, etc..) take place.

I do intende to cut the bricks square to the door, with an offset, but my concern was with where the bricks intersect the dome. I'm thinking they should be radiused to fit the dome, on that side? I've also seen posts with a "fire break"..not too sure where that would occur??

Here is some historical footage!

[GianniFocaccia]

Re: Under way in Socal

I like your idea of placing the top layer of floor splits inside the dome. Just make sure you leave a perimeter gap (1/4") so that as the floor expands, it doesn't put outward pressure on the dome itself.

Can you explain (or diagram) a sailor course of 5-7 bricks? Given the outside gap created from splits, I wonder if this is a good idea. I might just start building the dome from the floor up with horizontal courses that will continue upwards until you close it up.

Regarding the entryway and arch supports, just cut the bricks square to the door unless you want the herringbone pattern to be continuous throughout the entryway.

[cnicholson]

Re: Under way in Socal

So true John...own it good or bad I guess..so I had a revelation...Since I'm using splits throughout I am going to set a "sailor" course of 5-7 bricks on top of one row of splits and then set another layer of splits inside the dome...I guess you could say I'm doing the floor both ways.

A question I had is how to layout the opening. I snapped my centerlines on the "subfloor" and using a square (it's not in the right place in the photo I know!) I laid out a brick at 10" from center, on the circle, on each side. So do the bricks get cut at a radius where they meet the dome?

Ya know what, I think I am answering my own question now that I type it and think..and maybe not?!?

They would get radiused against the dome and then cut to not have a running bond on the arch supports?

Thanks all!!

[GianniFocaccia]

Re: Under way in Socal

Thanks, C-Nick. You do have it under control, just go for it. The best thing about building an oven 'your way' is that when you're finished you can call it yours.

[cnicholson]

Re: Under way in Socal

Man...that's pretty damn clean looking John... I thought I had it under control and your giving me a complex now! Thanks again for the clarification and that is kinda what I was thinking with the insulation too as the too much is never enough seems to apply there..

[GianniFocaccia]

Re: Under way in Socal

So when laying out the floor, if the dome was going to be outside the floor, do you then build the vent arch outside the vent landing bricks or do you build the arch on top of those bricks?

Since my design calls for a heat break between the dome and entryway, I will build my inner arch outside my dome arch, leaving a 1/4" gap between the two. The entire entryway and vent will sit on top of the flared entryway floor, shown below.

I love the smooth finish of saw- cut firebricks and would have probably ground mine down too, if I didn't have the soapstone. Just know that you don't 'set' your floor bricks, rather they just lay on op of your insulation, leveled by a thin layer of fireclay and sand. This allows you to attain a flat, level floor with no protruding corners or edges. If your splits do protrude anywhere, you'll need to grind them down.

Regarding insulation, I think a number of builders have 'filled the box' as you describe. It has to be the easiest (and quickest) method of insulating your dome. Right now my plans include ceramic blanket for the (first) hot-face layer, and back-filled with vermiculite.

John

[WJW]

Re: Under way in Socal

Congrats on getting rolling again. My thoughts on your questions are...

1. I can't imagine that the tiny airspaces between your splits could have any impact whatsoever on thermal performance. Splits are fine (and as previously noted) will sure make replacing a brick easy enough.

2. Width of flare is important in that (as you note) it impacts the ability you have to reach the floor with tools. I also think they look cool. My oven has an entry flared just wide enough to allow me to get everything with a hoe or brass brush. In my opinion, you want that as a minimum if you plan to bake bread. I say this because I like to clean out my oven before baking and I have no interest in reaching my arm into a 600 degree oven to whisk broom out some ashes.

3. Concerning the floor. I STRONGLY recommend a herringbone pattern of brick on the floor. It makes for some extra cuts, but I NEVER have anything tools, peels, etc hang up on my floor. Assuming you do that, minor variations in the height of bricks become irrelevant and sanding your hearth becomes totally unnecessary.

Bill