Tuesday, January 17, 2017

Building our Barrel Vault Wood Fired Oven


This is a short description of my barrel vault build that I have done here in Central Portugal.

The final internal size is a 1m squared floor with a arch height of 50cm.

I hope you enjoy and get some ideas from it. I wish to thank ukwoodfiredovenforum for their advice and support.


• 1: First I dug out a hole in the flower bed, on top of the stone wall, where the oven was to be built



• 2: Set up a form to pour in the concrete base



• 3: Pour the concrete base, which was about 5-6 inches deep



• 4: On top of the base I cast 4-5 inches of LECA (light weight expanded clay balls) mixed with cement to hold it's form



• 5: Then I cast a 2-3 inch heat retaining base, to add to the thermal mass, using calcium aluminate cement with large grain sand, as a flat base for the hearth bricks to sit on



• 6-8: I then dry laid the hearth bricks on a dry bed of fine sand and clay mixture, with the surround/edge bricks cemented in place to give support to the coming vault





• 9-10: Here I cut the bricks for the back wall, which had to sit inside and under the arches, due to possible expansion of the arches when heated




• 11: Put up the back wall, using calcium aluminate cement and fine grain sand



• 12-14: The first arch of the vault goes up. I had to leave out the last two bricks from each arch until the next day, as the refractory cement dried so fast that as I tapped them in they knocked out the lower curved bricks





• 15: Showing the form I used to support the brick arches as they went up



• 16: Some front arch and entrance designs, which changed several times



• 17-18: The vault in progress




• 19: The front wall goes up



• 20: And then the doorway arches, which are 65% of the total vault height (in the centre)



• 21: The entrance walls go on, with many comments about the Sphinx



• 22-23: The start of the flue and chimney




• 24-25: The barrel vault then gets clad in another thermal mass layer of portland cement, clay, large grain sand and some gravel, sitting on a chicken wire support. This was left to cure and dry out for a couple of weeks




• 26: Then on went the insulating 25mm ceramic fibre blanket. I was advised to put this on before the curing fires so there was less temperature differential from the interior and exterior



• 27-29: I then did a series of curing fires, starting at 100C and going up around 50C each day and finishing at around 500C, and trying to get it to cool down in between. I also did a bit of cooking at the same time




• 30-31: Then on went a second insulating layer of LECA again, about 4-5 inches thick. I had to use a makeshift form to hold it in place, using foam insulation boards. This was also left for a week and then had another set of curing fires to try and get out as much moisture as possible




• 32-33: Then everything was clad in a concrete layer about 3-4cm thick, to weatherproof and protect the LECA. This was then put through a couple of weeks of curing and cooking fires




• 34: Then on go two layers of plastic coating paint with fibres, to make it fully weatherproof



• Pizzas and lamb: Some shots of the many dishes we have so far made with the oven






• The next, and final stage is to clad the whole thing in stone, so that it blends in with the wall and garden. This will take a couple of weeks, and will update with images...

Read more: http://ukwoodfiredovenforum.proboards.com/thread/2811/barrel-vault-build-central-portugal#ixzz4W183beYO