UL 103HT class A chimney construction

[Charles2]

Are some UL 103HT class A chimneys stainless steel on the outside for exposure to the weather, while other 103 HT chimneys are black or galvanized on the outside for passage thru upstairs interior chases? Or are they all stainless steel on the outside?

 

[bholler]

some are galvanized never saw black

 

[Charles2]

At http://www.woodheat.org/flue-pipe-installation.html it says "galvanized...coatings vaporize at high temperatures and release dangerous gases." I realize they are talking about stovepipe, but if there's a chimney fire could the outer wall of the galvanized chimney get hot enough to vaporize the coating?

 

[bholler]

No if it did it would not be containing the heat like it needs to. You need to trust that these manufacturers have tested all of these products. And they have thought through of all of these potential problems you are worried about just pick a reputable brand and go with it.

 

[Charles2]

just pick a reputable brand and go with it.

Can you list the reputable brands to pick from? Or describe what make disreputable brands so?

 

[bholler]

Selkirk ventis duravent ect i personally don't like simpson products that much due to their disregard for industry standards as far as alloys of steel but there is allot out there that preforms very well and they seem to be holding up ok. I just wont install them but you need to make your own decision on that. I also don't use galvanized exterior but there is no reason you cant. And i am sure there are allot more good brands out there those are just the ones that popped into my head.