Thermal Breaks

[CapePizza]

When I think I'm finally getting ready to start building I notice another "feature" people incorporate into their builds which gives me pause to research. Thermal Breaks.... I think I understand their purpose (given that various areas of oven will heat up/cool down causing different rates of expansion). Are they necessary? What areas benefit from having a thermal break? From what I've read from people's builds separating the vent arch from the oven opening arch seems to be a place where a thermal break is placed. Any comments about thermal breaks would be helpful. Thanks.

[CapePizza]

Just a follow up... I just did did a search on Thermal Breaks and a lot of posts came up. So I'll read those. If anyone still has any suggestions, I'm (still) all ears. Thanks!

[mongota]

I think it’s most beneficial to separate the dome from the vent. The gap does not have to be significant, and using ceramic fiber rope as a gasket of sorts between the two makes it easy to not just include structural separation, but to seal the gap as well.

The other location where a break is sometimes included is in the floor brick, to separate the dome floor from the vent landing floor. Some simply use a cut line in the floor brick pattern. Other include an actual gap and place something in the gap.

I includes a break in the floor brick pattern, but also undercut the bricks and added a piece of insulation to fill that undercut. From the top, you see nothing.

I think the break between the dome arch and the landing arch is almost a requirement, it’s a structural issue. The break in the floor is more style points for retaining heat within the dome.

[UtahBeehiver]

Thermal breaks is an interesting topic and you will find both ends of the spectrum as well as the middle.ground. It really depends of you how you plan to use your oven, if you are going to cook pizzas and do a roast or something the following day, then TBs are not nearly a factor as a user who want 4-5 days worth of cooking from a firing. IMHO, here is my list of insulation areas in order of importance, 1 floor and dome insulation, 2 insulated door, 3 TBs. It is really builders choice, There have been some simple and effective TB designs done lately as well as elaborate ones as well. If you have the resources, material and time, go for it.

[JRPizza]

To retain the most heat for multi-day cooking you need to minimize hot insulated bricks touching cooler non-insulated bricks or concrete. The idea of the thermal break, other than relieving expansion stresses, is to keep the cooler arch from bleeding off BTU's from your oven. I don't think there is much data on how well they function, but for all the time and effort that go into building an oven most want to do all they can to maximize efficiency.

[CapePizza]

Thank you for the follow up comments and suggestions. Need to absorb all this. I've got the insulated floor in the plan.... The thermal break between opening arch at dome and vent arch I'll have to consider. Thanks again.

[rwiegand]

I did not incorporate a thermal break and I retain plenty of heat for three days of cooking (day 1 pizza, day 2 bread, day 3 roasts of various sorts). Seems like added complexity for no significant benefit and possibly some loss of structural support. A quality insulated door would probably give me another day; to my shame I'm still using a piece of wonderboard.

[CapePizza]

Loss of structural support is a concern.... and your note of added complexity with little significant benefit is also my thought. Will keep pondering it. thanks for the comments.

[SCChris]

I put a TB between my oven floor and the landing after discovering how much heat loss I had after replacing a firebrick landing with soapstone. I wanted a easy to clean material for my landing and firebricks weren't. I finally settled on a piece of granite for the landing and a thermal break separating the oven floor and the landing.
BTW. Soapstone is a great thermal conductor.

Best to you and stay safe!

Chris

[Baza]

CapePizza this was a rabbit hole I went down too - and - given my newbie status/skill - I was reticent. However, there was enough here in the Forum from some pretty solid builds that suggest - if you go for it - not such a bad idea ... so i did. Though not done my arch, etc. I will be doing a break between the inner arch and vent. I DID put one IN the vent floor (you can see how in my build) as Mongo suggests above. One that you can't see from above ... but it's there! I honestly don't know how much of a difference it will make - but if it is a bit and I have the time and inclination - what the heck!?

Good luck with your decision - either way - you're going to make great food in that thing
Barry