An attic insulation shield is required. This part can be purchased from the chimney pipe manufacturer (metalbestos 6T-AIS). Being that most pipe has a 2" clearance, can this sheild be comprised of a "wood framed box" or "sheet metal guard", instead of the AIS? Being that you can run a chimney, thru a "chase", I would think that this would be acceptable. (I have a vaulted ceiling making it difficult to use the AIS and I don't want to use a "support box" if possible)
Attic insulation shield
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How would you support the chimney?
The double wall sits in the support box, and the single wall goes up to that and interlocks.
Have done several vaulted ceilings and the box is not that bad, if you leave the minimum exposed from the finished ceiling.
The double wall sits in the support box, and the single wall goes up to that and interlocks.
Have done several vaulted ceilings and the box is not that bad, if you leave the minimum exposed from the finished ceiling.
Without the support box how will you attach the vent pipe to the chimney? or are you running class A all the way up? thats an awful lot of weight just sitting on the stove top. I thought the support box made the install easier and doesnt look all that bad and no need for an insulation sheild.
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You don't have to use a support box. Metalbestos makes an alternate support we call a "wing support". Two paddles, one on each side, are attached to the bottom length of chimney and screw onto the surrounding framing. The paddles swivel, so they can be adjusted to the pitch of the roof. With a wing support installation, you do need to provide insulation shielding. To accomplish this, you can either use Metalbestos's round sheet metal shield (cut on the diagonal top and bottom to match the pitch of the roof), or build a "mini-chase" around the pass-thru area, observing 2" clearance to the chimney pipe. In either case, an oval trim collar is used on the underside of the ceiling to act as a firestop.
Thanks Tom.
So, I can install the transition (DSAC) from black pipe to SS pipe in the attic? The DSAC is part of the PCK kit ("winged" assembly as you refered to it), it fastens to the bottom of the winged pipe section allowing the black stove pipe to slide onto it, making the transition from SS pipe to black.
So, I can install the transition (DSAC) from black pipe to SS pipe in the attic? The DSAC is part of the PCK kit ("winged" assembly as you refered to it), it fastens to the bottom of the winged pipe section allowing the black stove pipe to slide onto it, making the transition from SS pipe to black.
Hey Tom,
I was finally able to get a tech at Metalbestos on the phone. They answered my questions. I "cannot" enter the attic with the black stove pipe, its not rated for that application. I must enter the living space with the SS pipe and then transition to the black. But I can paint that portion of the SS pipe black, to match.
Thanks again for the help.
I was finally able to get a tech at Metalbestos on the phone. They answered my questions. I "cannot" enter the attic with the black stove pipe, its not rated for that application. I must enter the living space with the SS pipe and then transition to the black. But I can paint that portion of the SS pipe black, to match.
Thanks again for the help.
Mike,
How did we get from a vaulted ceiling installation to an attic installation? At any rate, in either case your insulated chimney pipe must extend at least 4" below the ceiling.
How did we get from a vaulted ceiling installation to an attic installation? At any rate, in either case your insulated chimney pipe must extend at least 4" below the ceiling.
I still think the support box is easier......no chase to build, no wing supports no insulation shield no painting SS pipe. but whatever you like best.
I did one application like Tom said. It was pretty clean. The wing support sits on the roof, with the stainless coming down into the living area ceiling. From there it transitions to the black single wall.
I had a large round heat shield on the ceiling, and an insulation shield on the other side of that in the attic.
I feel more comfortable with the box approach.
I had a large round heat shield on the ceiling, and an insulation shield on the other side of that in the attic.
I feel more comfortable with the box approach.
I didn't really care for the metalbestos box. This box just appeared too "large", it was 14" square and I didn't care for the exposed rivots and exposed edge seams. The "winged" (pck) component allows for round pipe to exit the ceiling, cleaner look.
Mike
I can understand your concerns with the appearance of some of the box style radiation shields. Mine I bought at menards and I have to say that the double wall pipe that they sell is the worst junk I have ever seen. I'm attaching a picture showing my radiation shield with the class A coming through about 1 foot to where the junction is made to the double wall. I painted the short piece of class A with black stove paint and I think it doesn't look too bad. Right now the final fasteners are not in the L shaped trim pieces so they are a little loose.
I have to go out on the roof tomorrow and cut the big hole (12" diameter to meet code clearances = 8" class A OD+2*2" = 12") then install the rest of the class A and then finally I can tighten the support clamp in the ceiling support box to provide the major downward support for the weight of the class A. I have about 18' of class A + another 8' of double wall all going straight up. I might need to fit an orifice plate to the chimney connector to throttle her down if the draft is too strong. I don't want a damper in my install....
Keith
I can understand your concerns with the appearance of some of the box style radiation shields. Mine I bought at menards and I have to say that the double wall pipe that they sell is the worst junk I have ever seen. I'm attaching a picture showing my radiation shield with the class A coming through about 1 foot to where the junction is made to the double wall. I painted the short piece of class A with black stove paint and I think it doesn't look too bad. Right now the final fasteners are not in the L shaped trim pieces so they are a little loose.
I have to go out on the roof tomorrow and cut the big hole (12" diameter to meet code clearances = 8" class A OD+2*2" = 12") then install the rest of the class A and then finally I can tighten the support clamp in the ceiling support box to provide the major downward support for the weight of the class A. I have about 18' of class A + another 8' of double wall all going straight up. I might need to fit an orifice plate to the chimney connector to throttle her down if the draft is too strong. I don't want a damper in my install....
Keith
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To answer the original question, for the products we deal with the AIS is NOT a listed component of the system and can be field fabricated out of... whatever. Just so you maintain clearances. Just dont use a cardboard box (it has been done).
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