Under way in Socal

[cnicholson]

Alrighty ladies and gents...just started piecing my pics together to start my build log and it turns out the first ones I have are from 2006- yes as in I started this whole proccess six years ago!! We remodeled our house and I poured the slab for the WFO at that time...so now a remodel, 3 kids and a crash of the real estate market later, I'm back at it with a November 1 goal. I'll get my pics up and going soon but I have a couple questions out there that I can't seem to find the answer to.

1. I'm using splits exclusively (smoking deal on 2nds) so I'm doubling up the floor. My concern is that if I lay the bricks on top of each other without mortaring them, the small (microscopic) voids in between the brick surfaces would cause a decrease in thermal performance.

2. I'm making a template/protector for the floor and want to do a flared vent hearth for oven access. Is there any concensus to an ideal amount of flare? I came of each edge at a 30 degree angle and it seemed too much astheically so I'm going with 15 degs. I stood at the opening with a broom just to get an idea and it seemed perfect.

3. Can't decide on putting the floor inside the dome or, because I'm using splits and there will be twice as many potential fluctuations in level, putting the dome on top of the floor. I'm leaning towards dome inside and a full height soldier course. Anyone have on caveats to that?

I'm bit by the bug and just thankful that I have a support group!!

[GianniFocaccia]

Re: Under way in Socal

Hey C-Nick,

Welcome back and congrats on getting back to your most-excellent project. I'm now two years into building my oven, so I know how tough it is time-wise with three kids (each with hectic multi-sport schedules).

Congrats on the great firebrick score (Pacific Clay?). I think splits make a fabulous-looking oven, and can even make for less cutting. My initial thoughts are the voids will be moot - just stagger the pattern and you won't end up with any more seams than with full-firebrick. I would put the floor inside the dome just for ease of replacing bricks, if needed. Replacing splits would be snap.

The wider the entry flare, the easier access you have, and the more 'European' in looks (which I like). A wider flare means a slightly more difficult vent design, but it can be done.

Conventional wisdom says full-length soldiers are not optimum, from a thrust perspective. Personally, I had a difficult time getting my 3/4-length soldiers to bond, so I yanked them out and went with horizontal bricks throughout. If I had to do it over, I would go the same route.

John

[cnicholson]

Re: Under way in Socal

John- Many thanks for the words of wisdom. If your 3/4 std firebrick soldier course didn't work, I think it would kind of be foolish of me to think I could pull it off w/ full height splits. And yes, they were pac clay. I think I am going to take a wet grinding pad I used on a concrete top to the floor when they get set though, they seem really grainy.

Also, the more I think about the space in between the floor splits I too think it would be inconsequential.

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?

Another thought I had was about insulation and couldn't really find a clear answer. Is 3" of loose Perlite, more or less, exactly 1" of blanket? If that's the case, I plan to gable house my WFO and I built the stand to spec. If I used 3 1/2" steel studs to frame it, and filled the ENTIRE cavity with Perlite it would be, more or less, 6 1/2" of loose perlite EXCEPT in the physical location of the studs. Not too sure what effect that would have if any?

The reason I ask is that Perlite around these parts in a 6 cf bag can be had for $20. Also what could be easier than dumping a bag of loose perlite in a "box" if you will....thanks again.

[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

[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

[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

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

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

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

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!

[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!

[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.

[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.

[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.

[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!).