39 inch Corner Build

[UtahBeehiver]

My rope was fairly flexible/compressible as I stuffed it in conformed to the gap. So my round rope became elliptical to fill the gap. I would think 3/8" or maybe 1/2" would be fine. I think my gap was about 1/2" and I used 3/4" or 1" braided rope. 61A Ceramic Rope 8.25.12.JPG

[JRPizza]

Thanks! I'll probably cut the chamfer on my bricks and mortar up the arch before I buy, as I am sure whatever gap I shoot for will end up slightly different
Is some sort of a spacer recommended to achieve a consistent gap?

[UtahBeehiver]

I did not use any type of spacer, just but cut all the bricks the same. Once stuffed with rope and sealed the final outside coating hides all never to be seen again.

[RandyJ]

It really depends on the road you get. The stuff I had for the Arch was called 1\4" but was fluffy and was more like 3\8" the one I used for the floor was denser and was labeled as 5\16" and went in to my gap nicely. I think it was roughly 1\4" gap both places.

Randy

[RandyJ]

I used the heavy card board from my insulation board box as it was roughly 1\4" thick with some wax paper to keep it from sticking.

Randy

[RandyJ]

I used the heavy card board from my insulation board box as it was roughly 1\4" thick with some wax paper to keep it from sticking.



Randy

[JRPizza]

Sounds good - probably what I'll do. It'll help keep the inner arch clean too, as I am not very good at keeping the mortar where I want it.

[DavidApp]

Hello JR


Thank you for the comments on my finish. I was looking for something different from stucco and knew that my stucco skills sucked.

I used 2 lengths of 3/8" rope in the air gap and the bricks compress it a bit, In the vertical sections of the air gap I stuffed Fiber Blanket in the gap.I overlapped the arch section of the vent with the inner arch and left a 1/4" to 3/8" gap in the vertical section.

I have seen another build using a similar arrangement for the entry into the chimney. Not sure where.

David

[JRPizza]

David, I thought about doing the overlap like you did, with notched bricks, but was not sure what the advantage would be. My "thin" arch bricks will be about 3 3/8 thick/deep, so I don't think I need to overlap them on top of the inner arch for stability. What was your thinking when you went that way, if you don't mind asking?

[DavidApp]

Hello JR

I was concerned about smoke escaping through the gap and I thought that it may add a bit of strength to the arch as the bricks were wider. Easier to add the sealing rope between the inner arch and the overlap.

David

[JRPizza]

All good points. How thick would your arch bricks have been without the overlap?

[DavidApp]

Not sure. I will check in the morning.

[JRPizza]

Thanks - also, did you lay the rope down then build the arch over it, or stuff it in gap when you were done? It seems like with post stuffing there is a good chance of snagging the gasket trying to insert it.

[DavidApp]

Hello JR

I laid 2 pieces of rope across the arch then built my vent arch on top of the rope being careful not to compress the rope too much.
The arch closest to the inner arch would have been 2 1/2" thick if I did not have the overlap.
The photo is of one of the bricks that I had to scrap as it was too thin to make the arch radius.

David

[JRPizza]

Gulf suggested I try an overlap too back in an earlier post but I was thinking I would put in a bevel like UtahBeehiver did in his killer build and RandyJ showed in his post #91, but I was not accounting for my planned 1.5 inch reveal and 4.5 inch tall arch bricks, which makes the vent arch 1.5 inches taller than the inner arch. I believe the top of their arches were at the same height. With the mis-matched heights, a bevel sufficient to provide a space for a gasket would take out quite a bit of brick (pic 1). I think this limits my heat break options to either cutting a notch (pic 2) or overlapping (pic 3). I think the overlap has a two advantages over the notch design - arch and chimney stability (a little more brick and mortar, and less chance of insulation falling off gasket if placed in the horizontal gap). I would probably forego putting any insulation in the vertical gap - does not seem necessary and without a notch to trap it more chance of fibers falling into the working area.