Please help with chimney chase terminology

[damon_sisk]

I am installing a fireplace insert for occasional use and am in the process of building a chase for the metal, double wall chimney that came with the stove. I want the chase to be wider at the bottom around the insert (56 inches) than the rest (about 24 inches).
My problem is with the siding. I am going to install Castia Stone over it, but need a concrete or stone piece to accomplish the transition in size. My chase will look somewhat like the attached picture.

It seems to be common to use a slab of concrete/other material, at an angle to drain water. I want pieces that are triangular, where the hypotenuse is in the orientation of the slabs in the photo and the other sides of the triangles are simply vertical and horizontal. Basically, I want to build two boxes (the upper box not a wide as the lower) and accomplish the transition in two pieces; one for each side.

What is the name of the transition portion of a chase, or who sells stone or formed concrete parts for the transition?
(PLEASE CLICK ON THE PICTURE TO SEE THE PART I'M TALKING ABOUT!)

 

[Warm_in_NH]

Not 100% sure I understand the question but if I do, you're looking for a material for the two small "roof" type parts of the box.
I would frame it out of wood like the rest, use a solid piece of slate or blue stone for the "angled roof part"
At leat that's how I've seen them done in the past. Probably pick up what you need a good local building supply or they may send you in the direction of a landscape supply company.

 

[kennyp2339]

The whole chimney needs to be framed out with dimensional lumber, covered with plywood, (don't forget about access door for the clean out / inspection) the a good moisture wrap. Wire up the whole thing using the proper nails w/ washers that standoff - to keep the wire / mesh off the wood approx. 1/2", scratch coat. Stone veneer it. a little tip is to using a bonding agent in the mortar mix (this will help the stone to stick to the scratch coat and not fall off), of course back buttering the veneer, and adding a little to the scratch coat. Caps (blue stone) get put on last. Then grout (make sure you have a rough brush, as the grout sets you brush the excess off to give it that natural look, imo its better than butter knifing it plus is sinks it in to keep the weather out.
Hope that helps, I use to do a few part time jobs with a mason years back, fun work but you diffidently earn every penny.

 

[damon_sisk]

Thank you Warm_in_NH, you are correct, it is the angled roof part I am interested in. The siding product is not like most that require wire mesh, scratch coat etc. Instead, each stone has brackets built in. To install the stone, you just screw the bracket to the wall. The bracket forms the 1/2" gap for condensation drainage.
It works well, but is a pain to work with around angles. That is why I'm looking for a triangular piece (rather than a flat slab) to accomplish the entire transition.

 

[begreen]

Could you make your own renting a masonry saw?

 

[therdlesstravld]

You can do ANYTHING with a good grinder and a diamond cut off blade. I spin a 7 1/4" diamond blade on mine and can make some crazy things happen.

Safety glasses and a mask are a must and im not the kind of guy to say that but it's true a grinder kicks up a lot of dust/debris.

 

[damon_sisk]

I could fashion them out of solid stone, but had hoped to avoid all the work by just purchasing them...

 

[begreen]

That would be elegant. For simpler, maybe cast your own out of cement and cut them? Or is there a large paver that you could cut diagonally?