I'm getting closer to my Dome!

[Aegis]

Well winter is waning in Ct. and it looks like I will be starting to work on the hearth floor and dome soon! Yahoo!!!!!!!!!! I have been spending many winter days reading the post of past builds and admiring the fantastic job everyone on this forum has done. I have no masonry skills, so I am at a huge deficit in the talent department. The builds I have seen here are truly magnificent, if I can achieve anything close I will be happy and hopefully my doubting wife will like it too! I have my stand built from last fall and amazingly enough, it made it through this wild winter! No cracks, no splits, no frost heaving, it made it through because of all the info on this forum! Thank you thank you thank you all!
Now I have read many, many, many posts about domes, vent transitions (which reading about those has put the fear of Zeus in me) and insulation etc.
My first question (of many future ones) I do not have a clear picture of the thermal break between the oven and the flue/front brick work. I am so clueless, I don't know if the thermal break is between the dome and the flue, or from the flue out to the entrance landing?
Here is a pic of the stand from last fall and hopefully soon it will be warm enough to start the dome without freezing temps at night.
Thanks in advance!
John

[dmun]

Re: I'm getting closer to my Dome!

My first question (of many future ones) I do not have a clear picture of the thermal break between the oven and the flue/front brick work.

This is something that's fairly new in oven building. My oven doesn't have one, and I'm not convinced of it's utility. It's hard to do without exposed insulating material, which isn't a good idea.

[Aegis]

Re: I'm getting closer to my Dome!

With the posts I read, I was thinking (sometimes never a good thing) that an incomplete thermal break of a 1/2" with a thermal bridge of less than an inch could be a good compromise. I did read of the thousand year old roaches and melted cheese posts. I'll see if I could draw this out, to maybe make it clearer.
Here is a one dimensional view, which takes care of the front to back thermal slow down. Making the bridge smaller will I think slow down the escape of heat to the out side, uninsulated sections. At least that is what I am hoping to accomplish! LOL

[Neil2]

Re: I'm getting closer to my Dome!

"I don't know if the thermal break is between the dome and the flue, or from the flue out to the entrance landing? "

You don't really "need" a thermal break. I put one in to keep the temperature of my landing/counter top area down. If you are going to add a thermal break to your design, it can go either before or after the flue opening. In mine, the flue opening is full width and is part of the thermal break. The side thermal break is achieved by a 2 1/2 inch thickness of insulating firebrick, the floor thermal break is a 1 inch wide ash drop, again full width.

For your detail, I suggest you use insulating firebrick instead of the gap you show. Local pottery/kiln makers will probably give you the four bricks or so you will need for nothing (if you ask them politely). They are always taking down and rebuilding their kilns and often have odds and ends lying around.

[brickie in oz]

Re: I'm getting closer to my Dome!

Here is the thermal break Im doing on my current build.
The flue will have a thermal break too, I need to cut a fire brick to go over the lintel which Ill do today.

My build.
http://www.fornobravo.com/forum/f44/...two-15241.html

[Aegis]

Re: I'm getting closer to my Dome!

"I don't know if the thermal break is between the dome and the flue, or from the flue out to the entrance landing? "

You don't really "need" a thermal break. I put one in to keep the temperature of my landing/counter top area down. If you are going to add a thermal break to your design, it can go either before or after the flue opening. In mine, the flue opening is full width and is part of the thermal break. The side thermal break is achieved by a 2 1/2 inch thickness of insulating firebrick, the floor thermal break is a 1 inch wide ash drop, again full width.

For your detail, I suggest you use insulating firebrick instead of the gap you show. Local pottery/kiln makers will probably give you the four bricks or so you will need for nothing (if you ask them politely). They are always taking down and rebuilding their kilns and often have odds and ends lying around.

Thanks for the advice,although I do not have the ash drop(which I hope I won't miss too much!) I will try and find some insulating firebrick.
Thanks
John

[Aegis]

Re: I'm getting closer to my Dome!

Here is the thermal break Im doing on my current build.
The flue will have a thermal break too, I need to cut a fire brick to go over the lintel which Ill do today.

My build.
http://www.fornobravo.com/forum/f44/...two-15241.html

Great pics!!!!!!!!!!!!!! I am thinking,(ok, I know if you don't think too good ,don't think too much!) that the insulating firebrick will be a good bottom and side break. For the bottom of the flue chamber, I will set some foamglass for a thermal break and then continue up with flue and brick work. Not sure if I can do that, but if that is not possible then the insulating brick will have to do. I am just thinking that heat love to travel up and the foamglas may afford more resistance towards that love of heat rising.
Thanks for the pics and you build is looking great!
John

[brickie in oz]

Re: I'm getting closer to my Dome!

I will set some foamglass for a thermal break

Whats foamglass?
Im in Oz and we dont get a hell of a lot of variety in products here for some reason.

[Aegis]

Re: I'm getting closer to my Dome!

Whats foamglass?
Im in Oz and we dont get a hell of a lot of variety in products here for some reason.

It is called Foamglas from Pittsburg corning, I am using it as the 4" insulating layer under the hearth. FOAMGLAS?, ecological cellular glass thermal insulation systems for durable solutions in building, HVAC installations and industry, produced by Pittsburgh Corning. Great stuff I hear from others that have used it. It is a foam insulation made from glass, as I understand it, glass containing millions of bubbles filled with co2 so when you scracth it, it smells like rotten eggs. But compresion strength and insulation properties are excellent. ( I hope)

[Aegis]

Re: I'm getting closer to my Dome!

Anyone in New England, know where to get roofing slate in Conn. I understand both Vermont and upstate New York have companies in the Rutland VT. area. But shipping one square ( I will be needing 100 square feet coverage) is cost prohibitive I would think. Please, All ideas and leeds are welcome!
Thanks
John

[dmun]

Re: I'm getting closer to my Dome!

Anyone in New England, know where to get roofing slate in Conn.

Look for used materials. Call demolition and roofing contractors, and find out who they sell their salvage to. Put an ad in craigslist. Central CT is full of 19th century structures, there must be a lot of slate around.

[Aegis]

Re: I'm getting closer to my Dome!

Look for used materials. Call demolition and roofing contractors, and find out who they sell their salvage to. Put an ad in craigslist. Central CT is full of 19th century structures, there must be a lot of slate around.

I will go that route, I had been a little hesitant, due to Conn. not having any salvage yards, they are called restoration or re-claimed antiques! That usually triples the price of dirt around here! It gets down right embarrassing to have someone tell you they will sell you reclaimed wood (taken from a barn that fell down) for triple the price. Now, if the barn fell, how good is that wood?
Anyway, I will try the craigslist route and call some roofers in hopes of stumbling across a stray square!
I have added this link incase you thought I was just kidding! http://www.reclamationlumber.com/index.html

Thanks
John

[Neil2]

Re: I'm getting closer to my Dome!

"that the insulating firebrick will be a good bottom"

I would avoid using insulating firebrick on the bottom if it is exposed. It is relatively soft and may suffer abrasion / damage through use. It is fine on the sides or top where it won't get much wear and tear.

[Aegis]

Re: I'm getting closer to my Dome!

Thanks Neil, You and everyone else on this site make it a wealth of knowledge! These comments are priceless, can never get too much advice, comments etc.
Again Thanks
John

[Aegis]

Re: I'm getting closer to my Dome!

Look for used materials. Call demolition and roofing contractors, and find out who they sell their salvage to. Put an ad in craigslist. Central CT is full of 19th century structures, there must be a lot of slate around.

I did try several reclaimation places and some local contractors without luck. I did get some advice on trying a slate quarry in NY evergreen slate co. Great people to work with and have experience selling and shipping slate for brick ovens. I just got my order in today and the slate is beautiful. Here is a link - Slate Roofs I talked to Phil who is quite knowledgable and helpful. (which for me was great, since this is another area I lack ANY experience) What have others on this site used for roofing underlayment? Plywood,cement board, pine or oak boards? And if you used slate, what did you secure it with? Copper nails, stainless steel screws? I would rather not use a material that is flamable for roofing, but I don't think using copper nails in cement board is a good idea either. As always, any and all help/experience is WELCOME!
Thanks
John