Advice on building an oven like this for show garden & home

[beckie]

A quick intro, my name is Beckie and I’m a Horticulture student. My classmate and I are building a show garden for our course, and our theme is eat, drink and be merry! We have decided to build a pizza oven for our garden, but must do so cheaply.

My dear ol’ mum has wanted a pizza oven for a long time, and so we have two options.

1: we build a pizza oven correctly the first time, then find a method to move the entire thing to my home (not a short drive), and with multiple speed bumps.

2: we build a cheap version using a weak mortar mix, then, having practiced, take it down and I build another at home.

The one snag with option two is that my partner’s father will be building us the custom metal door and chimney, so whatever we build at college, we must be able to build to the same dimensions at home so that they can be re-used.

I would like to build a brick, barrel/arch shaped oven as close as possible to the photograph above, but am looking for advice on the pros and cons of this type of oven, how you guys think it may have been built, and how I can build a similar looking, but potentially better version. I can already see from the photograph that the brickwork isn’t perfect, and so would work to get the arch much better. I also have no idea if this oven would have good enough insulation, or how I could achieve a decent amount of insulation whilst still having a brick exterior. Can anybody tell how the inside of the arch was made? I think that a version where the back of the arch has an insulated outer layer, with just a decorative brick frontal arch, would also be acceptable in terms of visuals.

I can’t find any original posts on whose oven this is, where it is or how it was made. Nor can I find anything else remotely similar (there may be a reason for that). I’m currently researching as much as possible through all of your forum posts and have found a good one called ‘compact vault guide’, and will keep learning more, but I hope that you will have some valuable advice!

Thanks in advance!

[oblertone]

Hi Beckie, at first glance the oven pictured appears to have a few 'issues' in terms of being used rather than displayed. Personally I'd consider your project as two separate entities, one a show oven for your garden, second a working oven for your Mum. The pictured oven appears to have a steel liner (oil drum) with a layer of brick over that; it also looks like the flue is sited inside the oven which means a lot of heat goes straight up and out, making it inefficient.

The show oven could be built cheaply from clay over a sand former, this is much more in keeping with the rustic look than a steel drum and far more effective. There are some excellent recent build threads on here doing just that. Use the learning from this to construct a more robust and long lasting oven for your Mum.

Regarding the door: The decorative outer door is just that, purely decorative; for an oven to work efficiently you need to be able to separate the flue fron the oven, this is normally achieved by use of a free standing door placed against a 'step' created by making the flue tunnel slightly larger than the dome entry. The outer decorative door sits at the exit/entry of the flue tunnel and is there to keep cats out of your oven and look cool. It needs to be able to swing entirely out of the way when cooking pizza otherwise it will impede your peel. Reusing such a decorative door is very straightforward, you just use its frame as a template for your flue tunnel.

i hope some of this makes sense; please ask if it doesn't.

ps - I had a similar dilemma and built a 'mobile' oven on a hand cart (see build thread below), but it takes six strong peeps to move it so it's pretty static nowadays.

[chas]

Hi Beckie, as per oblertone plus: if this is for show rather than use at college you can more easily demolish salvage and rebuild if you use lime mortar (lime putty is easiest of all) and omit the insulation. You can still light a few fires in it to get authentic smokiness. Might even bake a pizza.

So, trawl through the barrel vault builds on the Home Page, pick the elements of design that most appeal, modify for your circs and have a go!

Don't be put off by the long-windedness of most of our builds - you could build an oven in a couple of days - and do consider the 'pompei'... building that dome without formers is really satisfying.

Good luck, and keep us posted.

Chas.

[beckie]

Thanks so much guys! I think I'm going to go for a Pompeii style for home and re-use the external door and chimney (which I will put above the flue as it narrows), and just do an example decorative oven like this one at college with a lime mortar, we aren't allowed fires on campus anyway so really it's just for show. Plus I don't want to spend loads of time there trying to insulate the floor or roof, or waterproofing, and this arch will hopefully be quicker because no need to cut as many blocks, but I want to show some brick-working skill. And looking into it after your advice the airflow wouldn't be right in this oven because of the flue placement and size.
Quick question, instead of having an internal door to block off the flue, does it work to have a shut off on the chimney itself and just have an external door to keep the heat in while cooking? This is assuming that the flue is correctly positioned near the entry of the 'Pompeii' oven.
So glad there's a space for people to share and advise on these projects, super cool! And you're all very kind to help each other out!

[oblertone]

Flue dampers do work, but may be prone to air leaks as they are harder to seal than a flush fitting door; that said my door leaks enough air to keep a fire going all night, which is no bad thing on my oven as it has minimal (25mm vermiculite board) underfloor insulation. However, most folks (with fully insulated ovens) like to kill the fire completely using a tight fitting and insulated door; your decorative door will not have very good insulative properties, especially if it's cast-iron.

[chas]

Nov 7, 2016 14:31:15 GMT beckie said:

Quick question, instead of having an internal door to block off the flue, does it work to have a shut off on the chimney itself and just have an external door to keep the heat in while cooking? This is assuming that the flue is correctly positioned near the entry of the 'Pompeii' oven.

hi Beckie, and the answer is yes it does. Have a look at my 'Norfolk build' link below and you'll see that's what I do - I have a variety of old galvanised pots that act as chimney cappings for 'retained heat' cooking as opposed to 'live fire' pizza stuff as my door is at the front.
Good luck with the project. For complete ease of construction and dismantling/reconstruction maybe use ordinary potters clay mixed 50/50 with sand to stick the dome bricks together. Use the mortar for your 'show' brickwork. 

Chas