First oven - Barrel/Vault - Which bricks

[woolf26]

Hi All,

About to embark on my first WFO. Have been researching for months and drawing up plans and changing them and then changing them back.

First few questions of what i expect to be a few;

1. For the barrel and back wall do you need to use firebricks? Clearly it will be cheaper to use engineering bricks, but what are the pro's/con's?

2. I plan to put Foamglas down for my hearth before motoring in the fire bricks and a ceramic blanket over the barrel before covering with a waterproof render. Is this enough insulation?

3. Don't intend on putting a roof over the oven, should the render survive the weather?

I am sure i will have more soon enough.

Very much appreciate everyone's posts and helpful info.

Will be sure to post some pictures - laying the base slab with rebar this weekend. Wish me luck.

Jack

[awalker]

1. Fire bricks will retain heat better and last longer.

2. It depends how long you want to retain the heat. More insulation equals longer heat retention. See davenott barrel build.
3. Not sure on render never used it.

[awalker]

Good luck

[davenott]

1/ Firebricks slightly dearer, but worth it in my opinion, for reasons above.
2/. I'd lay the firebricks straight onto the Foamglas hearth insulation without mortar. This is what I did, on others recommendation, and allows for slight movement with heat expansion and contraction.
I'd go for as much insulation as you can afford. I find it's great for using the oven for so many other things using the heat left over from a pizza cook. This weekend I will cook pizzas tomorrow night for tea, cook gingerbread men for the children for breakfast, cook a whole lamb during the day, a casserole overnight, then use the residual heat to kiln dry for next batch of logs.
3/ K Rend is a good breathable and waterproof render, the is some good information on this site, detailing its use in people's builds.

[strope23]

Thats why I always go with trusted brands!