4 years ago I built a cob pizza oven and I love it with all of my heart. And if you start right now, you'll be able to say the same. YOU CAN DO THIS. YOU CAN BUILD YOUR OWN PIZZA OVEN.
So you want to build your own pizza oven? That's the very same thought that crossed my own mind several years ago.
I wanted to build my own pizza oven because I have an unnatural love of pizza and building things. So right up until the point that my knuckles started to ooze blood (more on that in a later post) this was my DREAM project. And frankly, even with the blood oozing knuckles it was a dream project.
And I've had a lot of dream projects. Building a 40' x 40' vegetable garden, getting chickens, and after living in my house for many years one day I realized HOLY CRAP I bet I could make maple syrup from that maple tree in my backyard. And I did. And you can do it too if you want - I have answers to every maple syrup making questions you might have in this guide.
My name's Karen. My nails are rarely done and sometimes my knuckles bleed. I'm O.K. with that.
Over the next few posts I'm going to give you all the information I can on how I built my pizza oven, but even after reading my tutorial I recommend that you do even more research. I read everything I possibly could about pizza ovens before starting to build mine, so I felt like I had a really good understanding of how they worked and how to do it.
At the end of this post I'll give you a couple of my favourite resources for information.
At this point you might be thinking ... "But Karen. Wait. I'm not a lunatic. I don't want to build my own pizza oven, I just want to make really good pizza at home.". No problem. I get it. If pizza from your regular kitchen oven is what you're looking for I have an entire tutorial on how to make perfect pizza in your regular oven. Everything from how to stretch your dough (not roll out) your dough and what to look for in a perfect crust and how to get it.)
Here we go!
Building a pizza oven can be broken down into 10 steps:
1. Build the base of the oven to sit on.
2. Insulate the base of the oven.
3. Build a sand dome that will be the form your build your oven around.
4. Mix your thermal mass layer of cob (clay and sand) and build your oven around the sand form.
5. Remove the sand form to create the cavity of your pizza oven (the actual interior space).
6. Mix clay and straw to create your cob insulation material.
7. Build your insulation layer around your cob oven.
9. Finish with a weatherproofing lime plaster.
10. Make pizza.
Today I'm going to talk about the base that your pizza oven is going to sit on, the insulation layer in that base, and how to build the sand form you'll be building your pizza oven around.
The base
The base that your pizza oven stands on can be made out of anything (cinder blocks, bricks, rubble) but it has to be able to hold 600-900 pounds (depending on the size of your oven)
My first thought was to use cinder blocks, but cinder blocks aren't cheap if you need a lot of them and they're big and heavy to transport.
So I ended up building my base on a series of 3 sets of sawhorses made with sawhorse brackets and 2x4s. I raised the sawhorses on pieces of flagstone so to help stop the ends from rotting. This way they won't ever be sitting in puddles of water.
Each sawhorse bracket can carry a weight of around 300 pounds, so a series of 3 can hold a load of around 900 pounds. Which is more than my small sized pizza oven will weigh. The actual base I built out of 2x4's, nailing them into the sawhorses.
Because you don't necessarily want to build a pizza oven directly on wood, and because a bunch of sawhorses is pretty ugly, I built ANOTHER base out of antique bricks which I got for free from my neighbour.
The bricks are secured with construction adhesive. (just a tube of extra strong gunk that you put in a caulking gun and squirt on like glue). At this point you're forming a pretty base, and a space for the bottom insulation of your pizza oven to go. Which you'll see in the next picture.
A pizza oven loses most of its heat through the top of the oven so some people don't even bother to insulate the bottom, but I wanted to do everything I possibly could to hold as much heat in the oven as I could. The more heat you hold, the more pizzas and/or other food you can cook.
The perfect thing to use for insulating in this case is glass bottles. Just get drinking and then line them all up.
I then added a layer of a mixture of clay, sand and straw to bind everything and insulate a tiny bit more. This will also be the base for my base. If that makes any sense.
Once your bottles and clay/sand/straw mixture have dried you can add a layer of sand. The sand is going to be what you lay your fire bricks on. The fire bricks are what you'll be actually cooking your pizza on. They aren't the same as the bricks in your fireplace which dissipate heat. THESE bricks hold heat. You can get them at most stone yards or large lumber yards.
When you're laying your fire bricks you need to make sure they are PERFECTLY even, perfectly level and perfectly mashed up against each other. If they aren't level on top, when you put your pizza or bread in the oven on a pizza peel, the peel will knock into the edges of the bricks in an annoying way much the same way when you're shovelling and you hit a piece of sidewalk that isn't level with the rest.
Lest you think I'm looking too cute and having an easy time of it, behold the wide shot.
Now that you've established you aren't afraid to get your hands (or planter beds, or backcyard or face or hair or feet or ferns or Buddha head) dirty, you can move on to starting to build your actual oven! Which is the fun part of course. Because if you're onto building your oven, you're clearly just moments away from enjoying hot, crispy, gooey, delicious pizza.
A cob oven when it's finished, looks like this. I bet you've been wondering haven't you? This isn't my cob oven, but they all look pretty similar.
This is a really big oven. You don't need one this big, but build it as big as your space allows. The bigger the oven, the more heat it holds and the larger pizzas you can fit into it.
As you can see there's a cavity in the middle of the oven, just like a regular oven. Or a fireplace. In order to get this cavity you build your cob oven around a pile of sand. Then when the oven has dried, you scoop the sand out, which creates the oven cavity.
You will need a few large (lumberyard sized large) bags of course sand. Use regular builder's sand from the lumberyard. The book I'm going to recommend at the end of this post includes all the exact amount of materials you'll need according to the size of the oven you want to build.
Now all you do is wet the sand and start building the world's most boring sand castle.
I knew (again according to instructions from the book I'm recommending) exactly how high the peak of my sand form needed to be. So I started building my sand dome, and then stuck a stick into it. Once I got to the top o the stick then I knew I was at the height I needed to be at.
Building the sand form is easy, but also pretty boring. There's no action. No suspense. Just sand.
Building sand form for cob oven
Building the sand form of your pizza oven is the easiest part of the job. It's also the most boring. You are building the world's most boring sand castle. But it will eventually lead to ... wood ove...
And that's it. The base and the sand form of your pizza oven are now complete.
In tomorrow's post you'll be learning all about cob. How to make it, where to get your materials and how to start building the walls of your pizza oven with it.
Thinking this is too much work? It's not. It's fun and rewarding and ... you get pizza out of it.
Now I also know the other thing you're thinking. You're thinking, "Wow. Karen hasn't written a single funny sentence since she started talking about pizza ovens."
And you're right. While you're normally screaming with laughter during one of my posts, I must confess that may be the end of the funny posts. I've lost my funny bone. Literally. My skeleton is now surrounded by something akin to 7 layers of pork belly due to eating pizza. A lot of pizza.
I'm a pizza pig.
And I'm O.K. with that.
Now let's move onto the next step in Building a Cob oven, Step 2.
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Thinking of building an wood burning pizza oven? Then you need to order the book "Build Your Own Earth Oven" by Kiko Denzer right now.
I also got a LOT of help from Sigi Koko the principle architect at Down to Earth Design. She was relentlessly patient with me and my questions. Watching her 4 part series of YouTube videos on how to build a cob oven will give you a really good idea of what's involved and how to tackle the project. I watched her videos over and over and over again. I suggest you do the same.
Hi, this is a fantastic step by step process with photos, I’m just wondering what happened to step 8 at the beginning of the post ‘building a pizza oven can be broken down into 10 steps’-did you happen to leave something out accidentally, or just a glitch with numbering?
Hi Karen! This is a great instructional for the cob oven. I have Kiko’s book and have been reading on this for close to two years. I plan on finally making the oven this year! My only issue is the clay. I have a field behind me that is clay heavy but I’m worried about using that. I just can’t wrap my head around how you know the purity. Do you know of any ovens made with purchased clay? Thanks and can’t wait to get mine going!
I LOVE your oven!
I am just curious the size of your oven and what you can fit in it, if you'd be willing to share. I have Kiko Denzer's book and plan to use ratios and measurements referenced in the book, but am just trying to decide on what size to build. It'd be nice to have a visual reference.
Hi Kinsi! It's about 27" high. At first I wish I'd built it larger so I could make 2 pizzas at once, but really it's easier to make and cook one at a time anyway. The most important part of the oven is the insulation (both the floor and the outside of the oven). If you don't do a good job on that then you'll lose all your heat and never be able to turn out perfect pizzas. :) ~ karen!
Okay, I’m fairly new to your blog( sister recommended - she use to live in Grimsby).
Moving to Manitoulin in Oct and this is my spring project. Got book you recommended and will watch YouTube you recommended. You’re my new favourite ... blogger? ( I’m not a blog follower). You make me laugh out loud almost with each post! Thanks Karen, you’re an inspiration!
Thanks Mary! I don't know if people still call what I do blogging or not, lol. I do. But I think that's a dated term. However I absolutely refuse to be called the more modern and in my opinion obnoxious and off putting term - "influencer" ~ karen!
How far back should the oven be from walkways and eating area? I read prev comment says back and top are not hot but how hot is it near the front?
Hi Karen. You have got me obsessed with your videos. I think I look at them daily. Could I ask a few questions if possible?
Is there anything between your bottles and the fire bricks beneath them
Diameter of the inside
Height of the inside
Width of the door
Height of the door
Thank you so much for your sharing and support
Hi Di! All of those things depend on how you're building your pizza oven and what size. That's why I recommend the book Build Your Own Earth Oven. It gives you all the ratios and formulas for calculating door height, width etc, based on the size of your oven. If you're building an oven you really need to get the book to accompany this post for instructions. The guy who wrote it is the King of earth ovens. ~ karen!
I had no idea Canadians were so cool! I'm totally gonna rock this oven this summer. THANK YOU!
You didn’t? Where have you been ? 😉
Hey Karen, 3rd time reading this set of posts and I think I am going to actually get started on this on the long weekend!
Trying to decide on the size, for perspective is the base of 2x4s, 4'x4' ?
The size can be whatever size you want it to be Christina. For the sawhorses, they always hold 2x4s. If you have a lot of room you can make a larger pizza oven that holds bigger pizzas, or two at the same time. If you're doing this, don't forget you really have to buy the book. It goes into the science and is more specific in terms of testing your mixtures etc. I'm not positive, but the entire width of the barnboard base is probably around 6'. ~ karen!
Hi Karen
How is your pizza oven holding up? Do you cover it at all in the winter.
I keep reading the elements can be bad for it if it doesn’t have a roof over it.
I love your ideas of saw horses. I really wanted to build a brick oven but am thinking of trying your clay method instead
Thanks for sharing all the info
Chelsea
It's holding up perfectly Chelsea. The lime plaster protects it from rain. And once fall hits I make sure to cover it up so it doesn't get wet and then freeze (which will cause cracking and crumbling). So I don't cover it at all in the summer, but cover it in the fall and keep it covered in the winter except for when I'm using it. ~ karen!
Thanks so much for taking the time to reply.
Not only has your blog made me want to build this oven.. I think I’ve convinced my husband to let me get chickens too
Take care
Hi Karen, I've probably read this bloog at least 15 times over the past 3 years! I'm actually going to attempt a build this month. A couple questions... what is the height of the base before the bricks? and I suppose this depends on teh cook, but what is teh desired height of the opening to the stove?
Thanks Joe
Hi Cindy, I've probably read this bloog at least 15 times over the past 3 years! I'm actually going to attempt a build this month. A couple questions... what is the height of the base before the bricks? and I suppose this depends on teh cook, but what is teh desired height of the opening to the stove?
Thanks Joe
It does depend on the cook, Joe. I just built it to what I felt would be comfortable for me. But anything in between table and countertop height would be good for most people. ~ karen!
Witaj Karen
Widzę tu bratnią duszę - mam podobne przemyślenia , nawet dość szczegółowy projekt pieca . Niestety z powodu choroby musiałem przerwać prace . Może kiedyś wrócę do tematu , ale na razie czegoś się u Ciebie nauczę . Pozdrawiam serdecznie , świątecznie i noworocznie : Wesołych Świąt , świetnego Nowego Roku 2017 , Jerzy .
Merry Christmas Jerzy! ~ karen
Hi Karen,
Your blog is an inspiration and extremely helpful and fun. The one thing we are struggling to understand are your layers. It looks like you have 3 layers of bricks on top of your 2x4s (one as "floor" and 2 as containment). But if we add bottles, mud, sand and full size firebricks we can't see how that all fits within the height of 2 containment bricks.... can you help?
Thanks!
Hey Alex. Thanks! Yup. It all fits. :) The bottles are covered only by a thin layer of the insulation layer of mud. It fils the space between the bottles and then just covers the top enough so they're covered. Then enough sand is added (I forget how much so that the firebricks ended up level with my regular bricks. ~ karen!
So excited. We've just taken possession of a new house and will be moving in next week. Backyard is a blank slate, and big enough for one of these :-)
To add to my excitement, I found a discount card for Chapters in my wallet, which expires today. So I ordered the book you suggested for $10 off.
Basically, the rest of my day is going to go downhill from here.
Did you recently post a DIY on a chandelier for your kitchen you purchased at Habitat and spray painted?? I thought I saved it. I have a project I want to do an d I need your help. I want to spray paint a gold colored chandelier dark like the one I saw on your post (I think). Can you help me??
Nope that wasn't me Syble. :) One of the other DIY bloggers. I can tell you that whenever I spray anything gold I use 24 karat Gold spray paint. ~ karen!
Love your oven. Just wondering the measurements on it. What the base size was and what size your oven measured. Decided how big I want it. Can you give any details on clay and sand used? Thanks.
Hi Karen
I know this is an old post but was wondering if you could tell me what size sawhorse brackets you used and where you purchased them. I saw some at Home Depot but there are different ones, also if you could direct me to the plans for the actual sawhorses (if there are some) yours have a brace at the bottom, most plans that I have seen don't. Also where you purchased your pizza peel from and the scraper for the coals. I want to make a cob oven this summer, and would appreciate this info. I live in Barrie so shopping in Canada, for me. Thanks love your oven, very cool (or hot)
Hi Debbie. I can't remember what size sawhorse brackets I got actually. I just bought whichever ones said they held the most. There aren't any plans for them in terms of bracing. I just took it upon myself to do it to make them a bit stronger. I got my pizza peel from a local kitchen store but you can get the same one here on Amazon. :) I got the scraper/brush from Amazon. You can get it here. The one other thing i'd recommend you buy is an infrared thermometer. It takes the guesswork out of judging when your oven is at 800 degrees. :) Have fun building it. And make it as BIG as you can. Also, the bigger your oven the bigger your pizza peel can be. Mine is smaller than I'd like but it's what I had room for. ~ karen!
Thanks Karen. Looks like I will have to find my Hippie dresses and do some stomping this summer (ala Lucille Ball, oh wait that was wine, LOL)
Karne, you ARE looking cute. But too cute? I don't think so. A good looking woman who can do stuff? I think I'm in LURVVVV...
Thanks - just what I was looking for - great site!
Thanks John. Welcome to the site! ~ karen
when building the insulated base of the oven, did you put bricks under the bottles or just directly on your wood base?
I own a culinary team building business in Vancouver, BC
I'm looking for new ideas for my clients especially one day programs. Is it possible for a small cob oven(s) be built in one day and to ready for baking pizza?
I would have anywhere from 10-30 people so number of cob oven could be in process.
Your feedback would be great!!
Julie
Hi Julie! No. Not a chance I'm afraid. Like the post says it takes several days if not weeks in between the various stages in order for the cob oven to dry properly. ~ karen!