Round shape

[ggoose]

Re: Round shape

What about rope gaskit used on wood stove doors and the like? You could grind a small channel into the outer arch bricks to hold it in place, but not deep enough to swallow the gaskit such that the inner and outer bricks touch...

Just a thought.

gene

[GianniFocaccia]

Re: Round shape

I will be putting tons of insulating blanket over the dome and around the bottom part of the flue, but I don't know how one would make a heat gap around the outer arch

I think Gene's gasket idea is a viable approach. Any gap (tscarborough recommends just a 1/4" air gap) will help as a thermal break. I would be inclined to cut the enclosure bricks so they make contact with the entryway just on the exterior surface. This would minimize the size of the thermal bridge and doesn't have to make a perfect seal since no smoke is ever gonna through there.
John

[david s]

Re: Round shape

This is how I did mine. The outer decorative arch it completely isolated from the gallery, the floor and the dome. I filled the gap with 6:1 vermicrete.

[Mike D]

Re: Round shape

The mortar will transfer the heat like the brick will. How is this any different than any other build? An igloo style will be touching the outer arch as well as square brick enclosures, right?

Mike

[Mike D]

Re: Round shape

I was thinking about using a thin layer of vermicurete, but didn't know if that would work.

[david s]

Re: Round shape

It works and is flexible slightly so copes with expansion pressure

[Mike D]

Re: Round shape

Ok- so if I put a 3/8" layer of vermicucrete between the outer arch and the decorative brick enclosure, I could still put a mortar seal on the front (outer/showing side). should I use high temp mortar or just the regular mortar that I will be using for the rest of the outer brick enclosure?

Mike

[david s]

Re: Round shape

Just use the vermicete mix.If you're concerned about it not coping with heat make it up with lime instead of portland, but I don't and it works OK

[brickie in oz]

Re: Round shape

Insulating fire bricks?

[david s]

Re: Round shape

Insulating fire bricks?

They will insulate but they're not flexible, so you won't get any cushioning benefit.A high temp caulk is another option.

[Mike D]

Re: Round shape

I have to use some sort of mortar for aesthetic reasons, even if it is only a superficial. The vermicrete is not the most beautiful mix.

[david s]

Re: Round shape

If you puddle around with it a bit you can get a smooth surface on the top.

[Mike D]

Re: Round shape

-Should I put a layer of the vermicrete first let it cure and then put the bricks on?

-I was thinking I could float the bricks on the sides without putting the vermicrete until I was close enough to go over the top of the outer arch (that would be when I would need the support of the vermicrete). Then I could fill in the sides with the vermicrete and go over the top at the same time and have it all a little more connected. (did that make sense?)
-That might end up being more work as I think about it.

Mike

[david s]

Re: Round shape

Sorry Mike I can't visualise what you mean. Can you post a photo?

[Mike D]

Re: Round shape

I was basically thinking of building up the sides of the brick enclosure without touching the outer arch and filling in the vermicucrete after/when I needed it to go over the top of the arch. But I don't think it is necessary. I will put a nice layer of vermicucrete on first and let it set up for a day or so then mortar the bricks to it.

Mike