Resilience

Anyone who has followed this blog over the last few years will be familiar with articles I post that demonstrate how, periodically, I neglect the oven and then have to undertake major repairs. This demonstrates two things. Firstly, I’m not very good at looking after my oven. Secondly, considering these ovens are only made from clay and sand, they are fundamentally extremely resilient.

My oven is almost seven years old now. I have, over the years, repaired the chimney, completely rebuilt the brick arch and replaced some of the outer layer around the front of the oven. You can see these repairs outlined in the following posts:

https://clayoven.wordpress.com/2009/08/09/repairs/

https://clayoven.wordpress.com/2010/04/14/winter-damage/

https://clayoven.wordpress.com/2011/08/09/neglect/

https://clayoven.wordpress.com/2013/04/29/time-for-major-repairs/

Last year I had to replace a large section of the outer layer at the rear of the oven. The following series of photos outlines the process.

As you can see, the oven is very straight forward to repair. I normally keep a bag of clay:sand mixture at hand, ready to use for patching-up the oven when needed.

Obviously, if you take care of your oven better than I do mine, you’ll need to do this less frequently but what I think this demonstrates is that these ovens are much more resilient than most people would expect.

Cracks!

A very  quick post about cracks. Lots of people contact me in a panic about cracks appearing in the oven layer during the build. Let’s start of by saying that it is very likely that you will get some cracking – in fact this is quite normal.  It only becomes a problem if the cracks become big and penetrate right through to the inside of the oven layer. Normally I’d just say, try patching the cracks with extra material and carry on but if they are significant then it might be worth starting again! It’s your call.

Why do we get cracks though? Cracks appear when the sand:clay mixture dries out and contracts. If you mistakenly use clay only to build your oven layer you will see significant cracks appear. You should not do that! However, you can get major cracks, even if you use the correct mixture of clay and sand. This happens if the oven dries out too quickly. The trick is to allow the oven to dry slowly, naturally if possible. If the sun is blazing you can use an old trick that builders use when building walls to help slow the drying process down – cover it with a damp sack, or even a tarp.  If you do light a fire inside to help with the drying process –  keep it small and gentle.

Thanks to Mungo Finlayson, an oven builder from Scotland, who shared these photos with me. It seems that some rare Scottish sunshine dried his oven layer too quickly. I suggested Mungo should try and fill the cracks before having to resort to starting again.

Long Time No See!

Apologies for the ridiculously long break from posting on the blog. I wish I had some sort of amazing excuse, like I have been trekking through the rain forests  of Borneo or have been away swimming every river in South America, but alas, I have not! Life has just run away with me, and by life I mean the day job. What can I say apart from sorry to anyone who was expecting this blog to be full of up-to-date, exciting articles relating to the world of clay ovens, pizzas and such like. Well anyway, I’m back (hooray I hear no one shout!).

It’s been a very wet and miserable winter here in southern UK. We have had floods and super high winds which resulted in a 24 hour power cut here at home on Christmas Eve (which was actually quite nice). It’s hardly been clay oven weather. You’ll see that I did some major repairs on my oven last May. I covered the oven up ready for winter in late September this year and I have not had a look since the onset of the dreadful weather. If I’m honest, I’m too scared to uncover it. I noticed a small hole in the top of the tarp, which covers it, this week. I fear the worst. I’ll have a look this weekend (weather pending!) but I know that I should have built a really good roof for it this year, as intended. I just never got around to doing it.

There are some fantastic and elaborate roof designs you can choose from, with many examples on the web (and some here on my site). I was thinking of doing something really simple – like the traditional example shown in the image below. Obviously, one would need to cover the sides during the worse of the winter months but a tarp over the top would do.

Traditional oven and simple roof.

I’d probably extend my chimney out through the top of the roof structure using a commercially available stainless steel chimney pipe.

Here’s a few examples from the Your Ovens section of my blog :

Whatever you choose to do, don’t leave the oven out to the elements, especially if you live in a place where it rains regularly. Learn from my mistakes  – this is what happens.

Don't try this at home!

Don’t try this at home!

If you have any examples you’d like to share, please do so either link to a photo on the comments section (below) or drop me an email and I’ll upload the photos to the blog.

It’s nice to be back!

Speak soon

Simon

Clay Oven 2.0

In a recent post I demonstrated what happens when a traditional clay oven is neglected and abandoned to the vagaries of a British winter. After waiting for weeks for the weather to pick-up a little, I finally managed to get out into the garden this week and got on with the long-awaited repairs. I thought you’d like to see what I have been doing.

First off, here’s a sad reminder of what the oven looked like beforehand.

Collapsed Pizza Oven

You can see that the brick arch and chimney had collapsed. You will also notice the house brick which I had placed in the hole which had burnt into the front beam of the plinth. This was always meant to be temporary but I had never got around to fixing it.

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The first thing I did was remove  the arch bricks, the chimney remnants and then strip-off the outer-layer of the oven. What you can see below is the inner layer, around which is wrapped  the insulation layer.

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I then removed the brick from the charred hole in the plinth beam and fitted a new, fire-proof tile in its place (I used a stone floor tile).

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For ages I have wanted to make a wooden former around which to build a new brick arch. As you can see below, I made this out of a few pieces of wood offcuts which I marked-up and then cut with a jigsaw. The arch pattern will allow me to build a much neater arch but also make it much easier for me to make a nice, tight fitting oven door.

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Next I fitted the arch pattern/former in place at the front of the oven. This required me to slightly re-shape the front of the oven layer which I did easily with a knife.

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At this stage I realised that it might be tricky to remove the arch pattern once the bricks had been built around it, so I added a couple of brackets to the front which could be used as handles. I then built the brick arch using clay:sand mixture as mortar, making sure that the key stone, in the top-centre of the arch was positioned to take the weight of the arch either side of it. This is important, if you don’t do this the arch will collapse under it’s own weight.

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You can see below how I then began to backfill the gap between the new arch and the oven using clay:sand mixture.

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Another modification I have been wanting to make for ages is to add a ready-made chimney. I managed to get hold of a clay pipe fitting, the front of which I rested on the top brick of the arch and the back which I rested on the solid, oven-layer. I cut a couple of house bricks and fitted them snugly, either side of the chimney, in order to give it extra support and then packed the gaps out with clay:sand mixture. I think it looks rather splendid!

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Here’s a close-up of the chimney.

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Finally, I rebuilt the outer layer with good old clay:sand mixture and, voila!

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Clay oven version 2.0 – done! What do you think?

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Winter Damage – Again!

The sun came out in the south-east of England yesterday so, like any keen oven owner, I took the opportunity to remove the winter cover from the oven for the first time since last September, 2011. It is now March 2012. So what did I find?

As usual, the rather rudimentary, tarp cover which I use to “protect” the oven has not been particularly effective. If you watch the video below you will see that water has clearly penetrated through. The outer surface of the oven is extremely friable. It seems that the water and frost have broken-down and eroded the clay from the mixture leaving partially unbonded sand, to a depth of approximately 1-2cm. Ouch!

Don’t Panic

OK, it looks pretty bad doesn’t it but apart from that, it’s not really too bad. I fired the oven up straight after shooting that video and cooked a rather splendid roast chicken in it (post to follow).  So it works fine still. Clearly she has seen better days, is in need of some TLC and remedial cosmetic surgery but functionally there are no problems. The oven fired well, it retained heat and nothing catastrophic happened as a result.

What to do?

When I get an opportunity I am going to scrape off a decent depth of the outer layer (I may even go back to the insulation layer) then add a new outer skin using the same sand:clay mixture as before. I will also add a new chimney (I might get hold of an old, clay pipe to put there in its place). Finally, I’m DEFINITELY going to build a decent cover for it this year, before the winter sets in. Mark my words….well…errr…don’t hold me to it!