Modern Design - Ambitious new oven build

[guym]

January 2019

Not much to add on the oven build front. The big news is that our Daughter was born in the new year, several weeks early but pleased to report that everyone is doing fine. We still hope to get the oven build up and finished in 2019!

Perhaps worth sharing a couple of links relating to the original build project which inspired our own:

This is the case study on the Architect's website:
www.shedbuilt.com/portfolio/wallingford-pizza-oven/

And here's some local press coverage which talks about the build in bit more detail:
www.seattlemag.com/article/pizza-oven-backyard-became-social-gathering-space

[guym]

January 2019

Just a quick update on costs to date. You may recall that our intention was to complete this build FOR FREE!! No money spent.

We quickly realised that wasn't going to be possible. However, our build costs to date have been pretty negligible, some MDF sheets (less than £20) and Decking Boards (£10). However all that will need to change soon. We'll be placing an order for the bricks, boards, vermiculite, flue etc - all of which is going to cost several hundred pounds. Definitely not free.

Accordingly we're changing our ambition from "building the oven for free - no money spent" to "completing the oven build - cost neutral".

What does that mean? Well, put simply, we're going to be selling some stuff on eBay! I was in the shed the other day and I came across all kinds of stuff we no longer need. Some of it is from the original building works we did on the house. There's some specialist roofing stuff that looks like it'll get £100 fairly easy - it's new in the box and goes for nearly £300 bought from a merchant. And loads of other stuff which should clear £30 to £50 each. All in all I reckon we'll be able to raise about £500 - and free up some much needed shed space in the process.

So, not free. Definitely not free. But cost neutral, we'll be happy with that!

[guym]

August 2019

Finally, some progress to report! And it's a good story...

I've just looked back to see when the first spade went in the ground - it was April 2017. That means it's taken 2 years and 4 months to get this far - and still no oven! Seriously, I now have a huge amount of respect for anyone who has a go at building one of these things from scratch - it's not straightforward. Given all my family and work commitments - time is my biggest enemy. I had started to wonder if I'd ever get around to finishing it, but a flurry of activity over the last few weeks has seen some progress which means the end is definitely in sight.

So, The Dome - the crux of the issue and the main obstacle to moving forwards.

Anyone who's kept up with this build so far may recall that we had a baby in January. Now eight months old I'm finally managing to find a little time to pick up other things. The original plan was to hand build a dome from 42% Aluminia Bricks. Given the slightly unconventional design we've gone for with the door opening on angle - my head started to hurt just thinking about how to design and build it. I started looking at calculations for how many we'd need on various websites. Every time I got close to thinking I'd solved it I found an excuse not to buy the bricks.

Inevitably I started looking at precast domes. But again, there were issues. Our base has already been built - so we'd have to find a dome that would fit. This is definitely not the way to go about building an oven! Secondly there's the logistics involved with getting a precast dome into position. These things are seriously heavy and pretty huge. Access to the back of our house is tricky - and definitely a problem for something so big. Finally, the cost of precast domes is not insignificant. Decent ones seem to start around £500 and they can go beyond double that.

I stumbled across www.milaovens.co.uk. I spoke with Luke there who seems like a really nice guy. Their precast system is built in sections - which means we'd easily be able to it get it into position. The price seemed fair and crucially - it was the right size. On Friday evening, beer in hand, I was literally just about to order a dome when I thought about checking eBay...

[guym]

The photos didn't really show much detail and the description didn't show dimensions. However, a few messages back and forth with the seller and a deal was struck.

On the upside - the oven had near perfect dimensions for our base; it was reasonably local; and it was a very good price.
On the downside - the listing described some damage to the external part of the dome; I couldn't tell what the floor was constructed of; and it was still very heavy.

Fast forward to Saturday afternoon and we're reversing onto the drive of the guy selling the oven. It turns out he'd bought it two years ago with the intention of building his own oven - but never got around to it - I know that feeling! The size and weight of it put him off and it had basically just sat on a pallet in his front drive all that time.

I'd brought my father-in-law along with me to help shift it. I asked the seller if he had any ideas on the best way to move it. He reached underneath one edge and lifted it up a couple of inches (I think to demonstrate just how heavy it was) before quickly dropping it back down. In that moment the oven floor kind of disintegrated. There was a sound of something breaking and a quick look inside revealed that the base and floor tiles had broken. The seller looked fairly devastated and was pretty apologetic. He apologised for our wasted journey and also realised he now had something very heavy and broken to get rid of.

When he'd lifted it I'd noticed that the dome had come away cleanly from the floor. I started to wonder if there might be anything salvageable. What I really wanted was the dome. I'd always imagined building a new floor anyway - that bit was fairly straightforward. Before moving it any more I asked if he'd be happy to do a deal if we could get the remaining bits into the car in one piece. All agreed that would be fine, we then started to lift the dome from the floor. What happened next kind of sealed it. The external dome perfectly separated from the precast section underneath. We now had two parts. A fire blanket insulation shell, covered in painted white perlite - underneath which was a one-piece clay/ refractory dome. A little bit more moving and the parts were off the pallet and in the boot of the family wagon.




The floor section wasn't really up to much. It had broken into three pieces - but could easily be put back together for use as a temporary positional guide. The floor tiles all fell off without much persuasion. I think they were just standard red quarry tiles - not really suited to an oven floor. But crucially the two parts of the dome, the 4" chimney flue, plus a heavy cast iron door (not original to this oven - probably off an old aga/ stove/ bread type oven - but still a decent match) were all in the car. The seller asked for £40 which I paid without hesitation. It was quite a bit less than the price we'd initially agreed. But that was before it fell apart.

I sense both parties had mixed feelings. I guess the seller would have preferred to get more for it, but possibly felt a bit relieved that he'd managed to get anything for it in the circumstances - and if nothing else he wouldn't have to get actually try and move it ever again. It was gone, off his drive, out of his life - forty quid in his pocket. For our part, we now had to get it home in one piece then lift it into position. On the surface £40 seemed like a bargain (certainly versus the time, cost and effort involved in building a dome from scratch). On balance, £40 seemed like a chance worth taking.

We got it home in one piece and lifted it into position.






In truth, I'd pretty much written off the outer perlite/ fire blanket dome. It was the main refractory dome that was always going to be most useful. Looking at it once we got it home it became clear that this wasn't perfect either. There were some cracks running across the top of the dome. They weren't terrible. The dome was still structurally sound - all in one piece and strong - but the cracks represent points of weakness and areas for heat to escape. I've done a quick patch repair with Fire Cement (Wickes own label - it's all I could get late on a Bank Holiday Monday - although the MSDS actually reveals it's made by Sika so should be ok). Before it's installed we'll flip the dome over and fill the cracks from the underside as well. I'd really appreciate the views of others on how these cracks might affect overall performance and/or tips on best way to repair? Should properly filling them with fire cement do the job?






The end is now very much in sight.

Most items needed to get the dome finished are being delivered this week.

The 42% Aluminia fire bricks for the new floor arrive tomorrow. The Calcium Silicate insulation boards for beneath the bricks arrive on Thursday - they are Skamol Super Isol boards - 50mm thick. We've bought Cementone ready mixed Fire Cement to lay the Skamol and Fire Bricks. Does anyone have any experience of this? Reviews from others seem decent enough. Due to the layout I've even become a bit more optimistic about re-using the perlite and fire blanket dome. It'll need a small patch repair around the chimney flue area. If I can get a day off next week the dome section may even get finished.

After that it's the home straight. A bit more insulation. Build the remaining side walls to the finished height (it will be lower than the Wallingford oven - which I think is good for us) - put the roof on and it's done. Planning on using 3 x 6ft smooth concrete gravel boards for the roof. We'll need to rout a circular hole for the chimney to pop through - but I'm definitely not planning on casting another concrete worktop - 5 foot off the ground! There's some fiddly metal panels to source, but I'm not overly worried about that.

Ambition is to cook some pizza in the oven before Christmas!

As ever, we welcome thoughts or feedback. Wonder if this might win an award for the slowest build on here??!

[devontiger]

Quote "Ambition is to cook some pizza in the oven before Christmas!"

Well what a story. You are very adventurous, well done.

I consider myself more than capable of building an oven, but I wanted it now. Not 2 years later.
Thats why I purchased an ebay one.
I've now had 3 years with my one, which was expected to last just 2 years!!!

Its still going strong. If it goes belly up, I'll get another one.

Keep your story going guym, it makes exciting reading.
Just made a couple of these from palette wood.

[guym]

Wednesday 30th October 2019


So, I booked a day off work to see if I could inch things closer to completion. Suffice to say that things did not go to plan!

Quick recap:

1. We're trying to build a Pizza Oven to a specific design at cost-neutral (no cost)
2. We bought a second hand dome back in August and managed to get it home in one piece
3. Since then it's been sitting under a waterproof sheet

Fast forward to the very end of October and the warm sunny days have been replaced by damp Autumn. Shorts, flip flops and cold drinks have been replaced by warm clothes and hot drinks.


You may recall that the oven had broken into three parts: 1. the actual fire dome, 2. the fire blanket and perlite shell, and 3. the floor (which we're not re-using). All of which have been sitting under this sheet since we got them home.




First task of the day was to fill the hairline crack in the underside of the dome with fire cement




Next up was cutting and laying the underfloor insulation. We'd bought a couple of sheets of 50mm Calcium Silicate board. Cutting them to shape was fairly straightforward. We just needed to line them up for final position.




The insulation boards are very porous so covered them kitchen foil to stop the mortar from drying out too quickly





So far, so good. Next up were the aluminium silica fire bricks for the actual floor. They were dunked in a bucket of water to aid adhesion.




Time to lay the floor tiles. With hindsight I wished we'd gone for a herringbone pattern, but it is what it is - and still looks fine. We used ready-mixed Bostik Fire Cement 10kg tubs. Again, with hindsight, I'd have hand mixed using lie, cement etc. The ready-mixed product was clearly much more convenient, but very sticky and hard to work. It didn't spread easily like normal mortar. In the end it probably saved a bit of time, but I'm not sure if it was worth it.







Everything coming along nicely. Stopped for lunch, ready to move the dome into position after a quick sandwich.


THIS IS WHEN DISASTER STRUCK!!!




THE DOME SPLIT IN HALF...

W

[guym]

WHAT NOW....

We were just debating the best way to move the dome into position. We'd moved it earlier in the morning onto a large beanbag on the lawn. It was sitting there quite happily, perfectly supported from all sides. Now, 30 seconds before its final lift into position my father in law picked it up to demonstrate how we might go about it. When he put it down, possibly on a weak spot, it broke in two! We stared at it, then at each other, a bit in disbelief - then started to think about what to do next. It was broken in two. Nothing much we could do but get on with it.

No point in crying about it.

On the positive side, it was a very clean break, right down the centre. This also meant that lifting it into position (the very thing we had just been debating, due to its size and scale) was now a doddle. Many of the newer domes we've seen for sale are supplied in 2, 3 or 4 precast sections - I guess for precisely this reason. They're easier to handle. The decision had been made for us. The cracked edge was applied with Everbuild Fire Cement and we proceeded to stick the two halves of the dome together, in position.









In truth it went back together just fine. Once the dome was in position we put a further layer of fire cement on the external line of the join. Next job was to lift the fire blanket and perlite shell into position. Worth bearing in mind that these things are very heavy and very awkward, but we managed it without too much drama this time.






The flue was mortared into position and that pretty much brings us up to date.

[guym]

The plan is to take another day off work early in November to finish the brickwork, add the extra insulation layer, and get the roof on before we get too many frosts. We're having a piece of steel cut to size to finish off the door entrance - same as the Wallingford oven. That should then complete the major work this year. Once the weather cheers up in the spring I'll be painting the brickwork and generally finishing it off and tidying it up. This also includes the area of garden around the oven which currently resembles a farmers yard!

We had a small test fire the following evening (Halloween) which went really well. The chimney drew well and the dome started to heat up. It had a lovely glow to it seemed to be working fine.






We're continuing to have a series of small fires for the next few days to help cure the mortar. It's clearly not the best time of year to be working - very damp and starting to get cold, but after all this time - it finally feels like we're finally getting somewhere. Thanks for bearing with us! Any feedback or comments very welcome...

[guym]

Final footnote regarding costs. You may recall us saying that we wanted to build this for free (which we soon changed to "cost neutral"!). We've been keeping track of the full costs so far and promise to share a summary of everything we've had to pay out. Once we've completed the build we'll find out what it's actually cost versus how much we've been able to sell to pay for it... More soon...

[oblertone]

You've got a dome, therefore it's pizza time ! I used a bare brick dome for over a year before adding insulation and a flue, you're well ahead of that schedule so get working on your dough recipes.

[guym]

5th November 2019 - Bonfire Night

Looking ahead to the final brickwork we need some way of supporting the brickwork that will form the corner above the over door. Fortunately there's a steel fabrication workshop on a farm a few villages away. The guys there were so helpful. I simply turned up, showed them a picture of what we're building and a few moments later there's a sheet of 6mm steel sitting on the laser CNC machine...






A quick grind with the hand tools to remove the sharp edges and that was it...




One final update - chimney cowl has now arrived and is in temporary position. Just need a dry break in the weather and the brickwork will be finished...

We've been having a few more trial fires.. so far so good...

[guym]

13 Nov 2019


First things first. Hats off to Mark McKenzie for his stellar build in Cheshire. In my head I'd aspired to that quality of finish - in reality, well - you can see our build!


Anyway, back to it. With the end very much in sight we'd been waiting for a break in the weather. It had been tipping it down for days - if not weeks - but finally a day looked like it could work to try and get up to roof height.

First job was to fire cement any hairline cracks in the outer shell




Then it was onto the brickwork




Next, laying the 6mm steel to support the brickwork corner above the oven door. As you can see - we initially made a temporary brick tower to support the weight - before soon realizing that we would actually need those bricks to finish off the upper section! The original (LEFTOVER FREE) bricks had now run out and we'd had to buy 75 more to finish off. Original bricks were Ibstock Reds, these were Wienerberger - but an excellent match




Checking levels. You'll notice that we had to insert some leftover firebricks to match the level at this course. Not ideal, but will be fine once painted...




Brick tower now replaced with a timber support!










And that pretty much brings us up to date. I've measured up for a piece of cut steel to go around the oven door. That will complete the front. It's with the fabricators as we speak - just waiting for them to call and say it's ready. It was tricky measuring up for it - so hope it turns out alright (fingers crossed). Really pleased with how the "floating" brickwork corner above the oven door has turned out. It finishes off the design and looks very angular, modern and dramatic. About seven more bricks to lay, some more insulation over the dome, 4 concrete gravel boards for the roof - and it is finished! Well on track to be finished before the year end. Just need another good dry day and we should be about there.

Incidentally, the next day after we completed the brickwork - the heavens opened again for another 5 days. I think we got lucky. The oven has been sat covered in plastic sheeting ever since...




"Pizza before Christmas!"

[markmckenzie]

You are too kind.
I wanted to do exactly the style of build you're doing but was daunted by the cantilevered concrete slab and getting the flue through the roof without leaks.
I can see light at the end of the tunnel too now. Good feeling as I don't like projects to drag on.
Of course, now mine's nearly done, I can think of 20 ways to improve it!!
Best wishes,
Mark

[guym]

19 Feb 2020

Where did we get to? I was going to make some Pizza before Christmas! Technically, that did happen - although the less said about it the better. Key learning - finish the build, slowly build up your test fires, only cook Pizza once the dome is good and hot.

So, the build is tantalizingly close to completion. Just the roof to put on, fit the flue and attach door plate surround. Simple. I just need a dry day. But life, my work diary and the weather have all conspired against us in January and February. But then, a morning became clear. Forecast said it would be dry. We were on...

First job was to move the (very heavy) concrete gravel boards from the front of the house where I'd left them - to the back. Each needed about a foot taking off each with the angle grinder. Next challenge was cutting the hole for the flue to come through...

[guym]

Sods law dictated that the hole needed to but cut through two boards. The concrete was only a couple of inches thick, but it still put up a fight. Overall we were really please with the result though...



Once the boards were all cut they just needed moving into place. Easier said than done. The rain that hadn't been forecast decided to turn up. And just generally lifting a very heavy piece of concrete, 6 feet into the air, to land on a specific spot, without disturbing all of the previous boards - and all within a confined working space - was something I'll be glad we don't have to do again. That said, it probably only took a couple of hours all told and was undoubtedly far easier than the alternative - casting in situ again - no thanks!








It's worth noting that before putting the roof on, we wrapped the dome in a whole roll of Knauf blanket insulation that was kicking around in the shed. It wasn't a particularly elegant finish - but added a final layer of insulation. Every little helps I guess.




And that pretty much brings us up to date. The roof is on - the last big job is complete. We fixed the metal door surround in place. All that now remains is to fit the flue and finish up the pointing. The weather really turned against us in the end - so we headed inside.

I'm hoping we'll get the chimney fitted and last bit of pointing done at the weekend - it's then finished!! Hallelujah!! Onto the test fires.

I can't quite believe it's taken this long. To be fair my work and family commitments don't really lend themselves to undertaking something like this. When we were stood out in the rain, cold and mud - all I could think about was a sunny afternoon or balmy evening at some point in the near future - flip flops on, cold beer in hand and the aroma of Pizza and a wood burning oven in the air - it will all have been worth it.

Right now of course, it still looks like a bomb site - but soon, it will all come together...