Contractor Talk - Professional Construction and Remodeling Forum banner

Yup...wood fired oven

28K views 217 replies 22 participants last post by  Tscarborough 
#1 · (Edited)
It's a little different than most so I'm hoping someone can give me some insight. This is what i'm working with. I have the structural pad poured but not the insulating pad and the bricks are all full size because it's just for layout at the moment.





The oven is going to be quite small I realise that and am OK with it. I'm sure i would be happier with a larger oven but I'll be glad to have anything really. That said, I want to make it as large as possible. So, would a 2.25" thick (firebrick laid as a shiner, or a header) be enough. That while it wouldn't be a huge gain it would be better than nothing. the other thing I could do would be 3"= 1/3 of a stretcher or 1.5 shiners, not fun all that cutting but that extra 1/3 of strength seems significant to me. The narrower i make the walls the taller I'll have to make the rise of the vault to lessen the thrust.

next...On advice from you guys I've made the floor of the oven quite high, it's @ 44" at the structural pad and if i go 3.5" of insulating pad and another 2.5" of firebrick and fireclay, that brings it to 52" . That seemed alright on paper but 44" is seeming pretty high right now (granted I'm 4-5 " below finished grade right now because flagstone isn't in yet so maybe that's it but even when i stand on the pad it seems high). So IF i feel like the floor of the oven will be too high and i want to lower it a couple inches do you think that 2" of perlcrete would be sufficient or what about going with splits for the floor?

And lastly. As you can see to try and save room i've got the front as a barrel vault and the back as a dome....so what I'm wondering is am I out to lunch? Also, should i make the rear a dome or build it up straight and bring the arch of the vault into it? it will mean some compound angle cutting, mostly by guess and by gosh but I'm into it now.
 
See less See more
2
#103 ·
hmmmm. So my outer arch is 1" wider than the inner arch (so I have the reveal for the door to sit against), the 1st brick after the skew back will have a taper cut into it or something to that effect anyway, and then the bricks directly on top of that will also have the an angle cut in (or laid at an angle or something I'll know when i see it. that way the throat is narrower than the opening. if the throat were the same size as the opening it would be square up from the bottom of the arch.

Just so we're on the same page. What I'm calling the opening is the opening into the firebox. The throat is the opening just before the flue starts. Then there is the vent....and I'm not sure if that is the entire area just outside the firebox opening or if it is the initial opening leading towards the throat. But maybe the throat is that first opening
 
#104 ·
I think you're just fine with an 8" flue Sean. Better to air on the bigger side than making it too small....not that a 6" flue would be a problem either.

A lot of guys call the throat (of an oven) the vent...the opening and transition
(To the flue) in the apex of the entry arch. Opening is usually called oven opening, to differentiate between the throat opening and entry opening.
 
#105 ·
Ok so the throat/vent is the transition between the opening and the flue. So... does it need to be tapered or can it be straight. And when you talked about the 60-75% and the 30-50% was that the beginning of the transition or the final size? Obviously if I go with an 8x8 my finished size will have to be that or smaller. I'm thinking that throat will start at 13" wide x4.5" deep and transition to 8" wide by 4'5" deep with either an 8x8 on top or a flue built from firebrick.

A big flue won't make for a lazy draught?
 
#106 ·
The percentages are for the initial opening. Usually transitions aren't more than a foot or two before it connects to the flue...and straight or tapered doesn't make too much difference.

An 8x8 would be good for an oven in the mid 20s, though I'm going on more of a hunch based on what I've seen happen with those ovens with smaller throats and flues. You have super heated exhaust cranking out of a small space...you don't want that puking over you're outside finishes. Every single problem like that (that I've seen or helped someone with) has been because of a small throat and flue. As of now, nobody that I know of has had to downsize a flue because of a draw problem.
 
#111 ·
My flue is rectangular 6x14 or so. It is firebrick laid shiner and stuccoed on the outside. It works surprisingly well for such a short chimney and doesn't smoke at all. My door is offset to the right, so the throat/smoke chamber is plumb on the left and slanted a little on the right. Overall height from top of arch to top of chimney is 2.5-3'. Hope this helps.
 
#117 ·
I'm going to do it this weekend. there's a pic on the Fb site, image 12.3 on the pompeii oven plans, that shows some sort of an adapter for a steel chimney almost right on top of the vent arch, so obviously some go virtually straight to flue size from the vent. another pic shows a fairly tall crazy sort of a taper, so some do it otherwise...FB is advertising both as a method so I'm sure either will work. As Stonecutter says...super hot smoke and gases, i'm sure they just want to go up as soon as they can.
 
#119 ·
I have no desire to actually switch to a metal flue, just the picture shows the adapter plate sitting pretty much right on top of the arch....meaning that there was little to no taper, that's all. I was at a Maple festival yesterday so hopefully the rain holds off today, it was supposed to be nice today but is ominous out there
 
#120 ·
I want a landing that is a contrasting material to the brick that the bulk of the oven will be faced with. It's an old reclaimed brick and there will be a foundation of mainly local stone that won't be very visible from the front. I'm also going to do a band course of stone (Stonecutter did such an amazing job with his granite on his last oven that I feel compelled to do something to add at least some interest). The band course will either be Indiana limestone or Ohio sandstone, both a buff or light grey colour which will contrast well with the red brick....also both are extremely classic which is where I'm trying to go. My first thought is to use either of those stones for a landing but they are both porous, so they could stain, and I'm wondering about their ability to withstand heat. I could do granite as a different contrast, but i don't have a decent source for any, plus it's already been done by SC. I'm not a concrete guy either so that's pretty much not going to happen...but it might????
 
#121 ·
A heat break is a nice feature to add between your entry arch and your decorative arch or finishes. I noticed a big difference in how the break on the last oven kept the arch from heating up as fast as the oven before. Neither one was damaged from the heat, but it's still a nice feature...and as a bonus, it will insolate the heat from reaching further away from the oven mass that without one.

Im looking forward to seeing what you are going to do with the stone....and don't let what I did on my oven keep you from using granite.
 
#122 ·
Heat break? An air space or some of that "wool" that they put on wood stove doors?

Granite is my preferred material (I KNOW it can take the heat and polished it can resist staining), but I don't have a ready source for it. If my cousin hadn't moved back to Ohio I could get some from him but he's been gone 10 years now. What's your thought on Indiana or Ohio sandstone and the heat and porosity
 
#124 ·
I plan on an airspace but I was going to point it 1/2-1" deep.

I may have found a piece of granite. I went to see a friend who works for a heavy equipment guy. The owner has tons of stone in the yard (literally of course). Most of it is the local limestone which i use for walling and flags but he sometimes has granite as well since we sit on the border between the limestone plains and the Canadian shield. Thought I might find something I could use, doubtful but worth a try. Talking with my buddy and he has a saw cut piece of granite that was a broken monument before it got started. He had thought of making a table out of it 5 years ago and it's just sat ever since. Said I could have it so I just might.

If i do take it though, that will be 2 different materials in the foundation, a brown limestone quoining and the typical local stuff, and 3 different materials in the oven area, brick, dark granite, and the light grey/buff string course....hmmmmm
 
#126 ·
Brick Brickwork Hearth Masonry oven Fireplace


Concrete Reinforced concrete Cement Rock Geological phenomenon


Brickwork Brick Hearth Property Masonry oven


Here's progress so far. I had to corbel out to give myself room for the facing brick. Can't remember exactly why I didn't bring the pad out initially but there was a reason...or not??? I don't mind it though, adds some interest, wish I hadn't done the dog tooth though, I maybe should have done dentils instead. I couldn't figure out how the end the dogtooth with it being projected like that so I just sort of stopped. A little clunky but oh well, probably should have kept the upper course going 1 brick more either side. I don;t do decorative brickwork much except in repair and even that isn't common

You may also notice that the brick isn't the same going up to the arch. That's because I made one side of the oven wider than the other because the right side will be all counter top so 2' deep and the left side is only 21" deep to match the grill.
 
#130 ·
Thanks guys. No colour in the mortar. It's actually just a pure lime mix, not NHL and I didn;t make putty, just bagged lime and sand. Kind of doing it as an experiment of sorts.

Oh and I remembered why I didn't just have a deeper oven area to begin with. Since it's a corner oven, the further I come out the wider the space and i didn't want to intrude on the grill any more than I was already
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top