New Build in Farnham

[coombsd]

Quick question regarding the transition between the main vault and the smaller front arch. In order to get around 63% height on my front arch I'm going to be left with a gap above the bricks of the front arch of around 12cm. Can I use calcium silicate board to fill this gap? I would cut an arch shape from 25mm board that would sit between the main vault and the smaller front arch and it would be then covered on the outside with blanket and castable. The issue is whether the board can face the fire and take the full force of the heat and flames...?

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[coombsd]

This is the proposed smaller arch that would sit up on a single brick at each side. It results in height of 37cm to the 57cm vault height but obviously would leave gap at the top.



here are some other photos of my build

[DuncanM]

Hi coombsd and welcome to the forum!

I'm very local to you (Woking) so if you ever need anything just give me a shout and I can offer my advice.

I would use spare firebrick to fill the gap, just any offcuts you have. Make the gaps as small as possible then fill with home brew high temp mortar - this is what I did. (I'll look for a photo and upload when I can). Then you can just cover it with your blanket and castable.

I don't think Cal Sil (I could be wrong) is intended for direct contact with the flames, so I wouldn't use it.

A few notes on your build... it's look great, although your dome seems very high (I'm not saying this in a negative way, more of an observation), you may find that when cooking pizza's you'll need to hold the pizza up to the roof for 5-10 seconds to fully cook the top.

And from the very brief glimpse at the rest of your garden it looks fantastic...

Good luck with the rest of your build and keep the photos coming.

Regards,
Duncan

[cannyfradock]

Helo Coombsd...welcome aboard.

I'm also not sure on the cal-cil board working in that position. I was going to suggest you raise the base slightly, but you would need to raise the arch by the 12mm x 2...(forget that. I just noticed you said 12cm.....I first read 12mm.)

It almost looks like your main vault structure has 1 or 2 bricks too many at the base. If this was the case then your front arch would work....but you wouldn't have your 63% (scratching head).

The cal-cil board may work even though myself and Duncan have doubts. If you plug the gap with bricks you will need full bricks to cover a gap like that so you may have to bite the bullet and buy/form another complete arch over the exterior arch.

Don't want to doubt your word but please re-calculate the hearth to underside dome height, and check that the front arch won't work with an extra brick. Your oven looks like a modular oven...i.e all bricks cut to exact size from a manufacturer......is so, everything should work.(if you've added an extra brick to the vault, you should be able to add an extra brick to the front arch.

Terry

[turkey]

lovely looking brick work there. Duncan's suspicions are correct cal cil board is not suitable for direct heat contact. I would use firebrick, you could cut them into slices to use less and bulk the thermal mass with homebrew.

[pre0ats]

It may be worth looking at the Coopers Bakehouse thread on the old forum (although you will need to register to view the thread complete with photos). He also came up against the 63% issue with the Kilinglinings pre-cut barrel arches. See link below:

woodovenukforum.forumup.co.uk/about1229-woodovenukforum.html

Hope this helps

[jonnycj]

I would get some of Liam from kilnlinings thin facing fire bricks, bed them onto cal sil board and use them to form your arch. If you look at Wirral WFO in new builds you'll see how I've done it. I've done it slightly differently in that I've formed my arch and then made a smaller arch which is removable to sit inside the main arch to give me the 63%

Must admit, firings have been relatively few this summer due to the bloody weather !

Your finished oven will look stunning in amongst those brick pillars - very Roman :-)

Keep going

Jonny

[cannyfradock]

PreOats

Good find. Coombsd has a problem which is not so easy to give an answer to. It's a shame that those ads and the problem with visiting guests not being able to see links and pics pushed us to changing forum provider.

Terry

[coombsd]

So I took the advice and cut up some left over firebricks to form the infilling arch. I then lagged the whole thing with 50mm of body soluble, a layer of loft insulation, tin foil and wire mesh. It then had a week with a heat lamp inside to warm it through and try to dry it out. And finally a fire...




First firing...

[coombsd]

Next, I had a proper builder make me the exterior arch in red brick, we then rendered with 8 bags of castable. The castable is about 20mm thick. What do I do next? Should I give it another layer of castable or can I give it a final coat of K-Rend for a nicer finish?

[rivergirl]

It's looking good!