Changing chimney to Class A

[cantex]

Excuse my ignorance.

Existing fireplace when we moved into house
Built in 1981
Corner fireplace with floor to ceiling brick facade, with firebox insert
Chimney through gabled one story roof
Chimney was torn off in recent hurricane. Basically took everything off at the roof line.
Got on the roof and looked down to see that chimney was triple-wall constructed of 9" pipe on firebox, surrounded by 12" pipe, surrounded by 15" pipe, all extending full length of chimney to cap.
Exterior portion (above roof line) was surrounded by metal 'faux' chimney (basically a five foot tall box which has a brick painted appearance)
I want to change the whole chimney over to Class A so that above the roof line it will just be stainless pipe with a cap, instead of the faux surround chimney.
My problem is that I can't find any manufacturer that makes a 9" id double-walled insulated pipe to attach at the firebox. The closest I have seen is a local home improvement place has 9" od with 6" id but there is space between the id and od that is open through the length of the pipe. That means if I mounted it to the firebox, each 6" pipe would sleeve together fine (the outer locks together) but this would allow heat coming off the firebox to pass up the non-insulated space betwee the two pipes.
There is plenty of clearance all around (if you look down from the roof, you can see behind the interior brick facade, forms a large triangle of dead space with about 2-3 ft clearance on all sides and open all the way to roof line).
Is there an adaptor to go from stovepipe to Class A, or can I find an adaptor to go from the 9" stovepipe takeoff from the firebox to the 6" or 8" Class A?
Can I safely just use the 9"od/6"id Class A because of the amount of clearance?
Any other suggestions?

 

[cantex]

Just getting back to checking on this thread. New thoughts since my original post. The wood burning fireplace is a Martin. No longer available and the triple wall pipe is incorporated in the top of the firebox so it will be hard to rig it up without loads of duct tape and rubberbands. (insert smiley of choice here)

Considering a gas insert with direct venting out a sidewall, and just have the roofers put a new sheet of plywood over the hole and shingle over it.

 

[MountainStoveGuy]

You cant vent a insert throught the wall, its a co linear system, you need to install a new zero clearance direct vent fireplace that has a coaxial venting system. You can also buy a anchor plate to put on top of the old firebox that would adapt it to class a chimney.
Ryan

 

[cantex]

You cant vent a insert throught the wall, its a co linear system, you need to install a new zero clearance direct vent fireplace that has a coaxial venting system. You can also buy a anchor plate to put on top of the old firebox that would adapt it to class a chimney.
Ryan

Thanks very much for your reply.

Had a chimney guy come by the other day. He wants $2400 to rebuild the chase on the existing fireplace. We live in Texas. We use the fireplace about half a dozen times per year, strictly for ambiance. I don't have a problem paying good money for a good job but I got to thinking about other options such as the gas insert or just changing out the whole thing for a gas fireplace (as you suggested above with the zero clearance). I'd rather spend an extra thousand or two (if that's what it took) to just convert it over to a nice clean-burning gas, instant 'on', wife-will-be-happy, fireplace. I am obviously not wise in the ways of fireplaces. I also asked the guy about affixing an anchor plate to the top of the existing wood burning fireplace and running class A and he basically looked at me like a dog with his head cocked sideways and said, "No."

 

[MountainStoveGuy]

LOL, thats what anchor plates are for. I would go with the zero clearance idea, its much easier, and a insert wont work for ya unless you can take the venting up the old chimney. Zero clearances you can buy that look great and wont blow you out of a room, inserts are very efficient and you might overheat your self down there in texas.
Ryan