Alan Scott oven project begins

[Gulf]

I will be using firebricks for the hearth, then under that will be a 3 1/2 inch thick hearth slab for thermal mass,

Have you thought about turning the fire brick on edge. That is 4.5" of thermal mass? Many bread bakers have done this. Going with your plans, make sure that the "hearth slab" is a refractory blend. Otherwise, if you were ever able to heat saturate it, it will spald. Those tiny little explosions will loosen the connection with the floor brick making it even harder to heat. Imo, you need to rethink this.

[astroinfidel]

Thanks Russell,

I will check out those insulation leads.

Dean

[astroinfidel]

Hi JR pizza,

I guess how much mass is considered excessive depends on a few things. I have free unlimited firewood, and I am going to be baking mostly bread. I think if you are going to be mainly using the oven for pizza the hearth mass would be considered excessive. But I am building this for bread, and for the long term. It is located on land that has been in my family for over 100 years, and I hope it is still being used here for baking in another hundred or two. I likely won't use it commercially, but I want the option of someone being able to if so desired sometime in the future. And I love the idea of firing it once for the day for bread, and then being able to cook dinner without refiring it days later. So I will be happy to have the hearth mass. I am retired and have lots of free wood and the time to let it heat up, so it just isn't an issue for me.

I have been using my cousin's Pompeii style oven that he built from FB plans. It is a big one..48 inches, and when I fill it and get good steam from the loaves, it produces fantastic bread. But even when fired for about 5 hours, I can't get a second bake out of it. I am down to 400 F by the time the first batch comes out, and it doesn't recover. So for my purposes, I did not find it had enough thermal mass.

Dean

[UtahBeehiver]

CaSi board, minimum 75 PSI compression rating recommended, there are may brands out there, Thermo Gold 12 is one, FB store uses AlSi board as well, It is substantially more costly than v or p crete. Again, look at KDs build, he is doing it right, using both CaSi and V/pcrete.

[JRPizza]

I don't know what plans you are following but if I remember right the original plans had an excess of thermal mass in the floor (sort of a floating island), whereas I believe the newer plans have a more reasonable mass sitting on top of efficient insulation similar to the FB oven plans.
Edit - I posted this and when I saved your last post appeared. Having a layer of firebrick sitting on top of and thermally coupled with a 3.5 inch slab will certainly work but will also take lots of wood and longer firing times. Most ovens on this site have bricks laying flat (~2.5") and if more thermal mass is desired bricks are laid on edge for 4' of depth. These ovens produce some quite long cooking times. I didn't see if you are planning on doing commercial type baking, but if not you might want to consider cutting back on the floor mass.

[astroinfidel]

Hello Russell,

And thanks for the welcome. I would actually be curious what the best modern material would be for under hearth slab insulation. I will be using firebricks for the hearth, then under that will be a 3 1/2 inch thick hearth slab for thermal mass, then the insulation layer. The plans call for vermiculite/cement at 6/1 for the insulation layer, but I have heard that there are better alternatives available now. I would like to insulate it very well - as much as 3 to 4 inches of synthetic material if possible. I have been searching online but have not had a lot of success yet.

I will let the foundation slab cure for a week before starting the block walls. I just picked up the blocks today.

Dean

[UtahBeehiver]

Welcome to the forum. We do not see a lot of Alan Scott ovens on this site but we can offer a lot of newer technology and material suggestions to make your oven more efficient. Do take a look at the new barrel oven that Karangi Dude is building, he does a lot of bread and non pizza cooking and his build is top notch and he teaches WFO cooking.

[astroinfidel]

Hello everyone from rural Quebec. I have just begun a 32 x 36 inch Alan Scott oven build, and will document it here and hopefully find advice when I need it from others that have gone before me. I can see from reading posts here that this forum tends more towards pizza ovens, and many consider the Alan Scott design to be too massive and that it takes too long to heat. This is not a concern to me. I am retired on a bush lot, and my focus is on baking bread. I will be using the book "The Bread Builders" as my guide. I poured the foundation slab yesterday, and am going to keep it wet for at least a week before starting the block walls.

Sorry if the images are out of order. They were not uploaded that way and seem to have gotten mixed up somehow.

Dean