Sell me on the pros and cons of steel vs masonry chimney

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blucoondawg

New Member
Sep 23, 2012
20
Northern Wisconsin
I have no experience with steel chimneys, my current chimney is a masonry chimney with a square flue, it is in bad shape and needs to be replaced, lining won't work as the problem is the concrete block cracking not the clay liners. I have been told steel is better but I have no facts on that or real reason for it being better. My current chimney is outside and would likely have to stay there at least until I remodel my home and add on. My stove pipe exits my basement about 18" below grade and goes into the bottom block of a masonry chimney. I would think for an inside application the steel may be preferable but I think outside the steel would cool faster than the block causing more creosote issues? Anyways I would like some opinions on the 2 styles and why one is better than the other, cost or time to construct is not an issue, I am more concerned with the function of on vs the other.
 
Class A chimney is insulated really well. With 1200*F flue gases moving through, you can put your hand on steel jacket for 10" or so. Flue cross section stays the same as flue exit - eg. 6" or 8" = better draft. Therefore, you can use shorter length than big 8"x12" masonry chimney.
 
the problem is the concrete block cracking not the clay liners​
That's one con. Class A chimney pipe is stainless steel pipe that is double walled or triple wall depending on brand with a layer of insulation between the two which helps the flue gasses stay hotter longer thus reducing the condensing of flue gasses and causing creosote. The inside is stainless steel which creosote usually doesn't stick to unless you are burning unseasoned wood or smoldering your fire. Because the chimney stays hotter is also improves draft.
 
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The SS also heats up faster.

I have seen thirty year old metal chimneys in much better condition than the masonry chimney I tore out of my house.
 
A masonry chimney over say 30 yrs is going to cost more to maintain and it will be less efficient. I would sooner put up a good metal chimney and then chase surround it, than put up a masonry chimney, especially in areas where the earth likes to shake things up now and then.
 
Class A chimney heats up faster. But all it will take is getting bids for building a new masonry chimney and then bids for a good Class A stainless steel one. No contest.
 
I won't be getting bids on anything, I don't hire contractors unless I absolutely have to. I know the SS chimney sections are expensive, I also know the material for a masonry chimney isn't overly expensive. The steel chimney would go up faster obviously. My biggest concern was I don't have experience with the SS chimney so I don't know how long they will last, I have seem many indoor masonry chimneys last a long time, I haven't seen much steel in my area so I didn't know how long it lasts, I don't want to go through the building of a chase and everything and then in 10 years have to tear my walls apart to replace a section of pipe. I am sure this wouldn't be a problem it is just something I am unsure about.

I am not against using steel but I guess I wasn't really wanting to have to build a chase in my house right now, I need every inch of space I have available until I remodel and add on. but maybe that would be the smartest way to go about it.
 
Some (Supervent), if not all Class A has a lifetime warranty.
 
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AS no one has touched on this, The appliances with efficiency ratings in the 90's do not provide a warming flow of heat constantly like the old standing pilot units used to. This allows condensation to build all year long in the masonry flues. This condensation is loaded with acidic byproducts of combustion which attack the mortar joints. This is what causes most masonry flue failures in recent years. Depending on the appliance/s you will see plastic or ss pipe tips extending out of older flue systems, ( unless of course it was run out the side wall) top of masonry flue is sealed around pipes. a lot of 60 year plus mortar joints need to be redone just because of mother nature. Out side blocks cracking suggests severe water migration likely from internal as well as external sources. Class three flue is only needed for solid fuel appliances, 90% oil/gas run on B pipes either way the area consumed is less than a traditional masonry construction .
 
I've never cleaned a masonry flue, but I clean my own steel liner. Easy! I used to disconnect my old stove and tape a plastic bag around the end of the flue pipe before running a brush through from top down (my pipe was inside a masonry chimney, no clean out T). I now have a new insert and will be doing my first sweep soon. Should be easier than ever, since I don't have to remove an elbow now!
 
There is nothing superior about a masonry chimney except aesthetics with some of the really fancy brick installs. Whatever a masonry chimney can do, a steel chimney can do better. The steel pipe is cheap (compared to masonry)and fast to install. Lasts longer with no worry about mortar maintenance or recrowning. Is more efficient since it better maintains flow, velocity, and warmth with the superior insulation.

Why would anybody build a masonry chimney? Tradition or looks is my best guess.
 
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I like shiney steel better than earth tone blocks.

Blinking lights also entertain me.:p
 
I'm prep'ing to build a new two-flue chimney in 2014-2015, as part of a major renovation. It will almost certainly be a masonry stack with stainless liners.
 
Steel is real, I just changed out my 30 year old block chimney a 1 1/2 yeas ago and I think steel is the way to go. for the reasons mentioned above.
 
Next house will get insulated steel. Its hard to get good masons in my area and having battled flashing leaks and having to replace the top of my chimney due to acid attack on the flue tile from an high oil efficiency boiler, I dont want anything to do with masonary. If I want thermal mass, I would much rather spend it on storage.
 
Right, if thermal mass is the goal then install a masonry stove.
 
I won't be getting bids on anything, I don't hire contractors unless I absolutely have to. I know the SS chimney sections are expensive, I also know the material for a masonry chimney isn't overly expensive. The steel chimney would go up faster obviously. My biggest concern was I don't have experience with the SS chimney so I don't know how long they will last, I have seem many indoor masonry chimneys last a long time, I haven't seen much steel in my area so I didn't know how long it lasts, I don't want to go through the building of a chase and everything and then in 10 years have to tear my walls apart to replace a section of pipe. I am sure this wouldn't be a problem it is just something I am unsure about.

I am not against using steel but I guess I wasn't really wanting to have to build a chase in my house right now, I need every inch of space I have available until I remodel and add on. but maybe that would be the smartest way to go about it.

Nothing says you have to build a chase unless you want it just for looks. You no doubt get a little bit colder than we do here but our chimney just goes up alongside the house and we have no problems with it. The danged thing is actually too short too so if one listens to the pros, our chimney should not work at all. Yet, we do not have a problem.
 
I grew up in Northern Maine and pretty much only metal chimney you see are on trailer homes. When I put in my stove my Dad asked me why I was putting in "that chit trailer house chimney". "It's what we use up here Dad... bricks are $$$$"


The Metal Bestos (I think that's what it is) is popular up here. One lady I know ran the same chimney for almost 30 years before pulling it when they installed a new Blaze King. Chimney was beat up a bit but was still safe to use.
 
Ya, we've seen lots of them on mobile and also modulars. However, over the past 5 years or so I've noticed more and more of them running up along side of the house just like ours. Some really look odd because they put them way out from the wall to keep from putting any bends in the pipe going around the eaves. But, they work and work quite well.
 
I think it's just one of those "been using xyz for years and years so it must be that way". The same that it's very rare to not have a basement down there, but up here it's not very common. Most houses only have a crawl space.
 
Why would anybody build a masonry chimney? Tradition or looks is my best guess.
Or lack of knowledge. Some people also think stone is the best because "thats the way dad always did it".
 
I would call that tradition. We do it just cuz dats what we do.
 
Nothing says you have to build a chase unless you want it just for looks. You no doubt get a little bit colder than we do here but our chimney just goes up alongside the house and we have no problems with it. The danged thing is actually too short too so if one listens to the pros, our chimney should not work at all. Yet, we do not have a problem.

Well, my current masonry chimney is outside, it is just bare block all the way up, nothing fancy, I was thinking if I used steel I would put it indoors up through the floor and ceiling/attic with a chase around it. I don't know if I could use the steel chimney outside what would I do burry it in the ground? I have never seen the steel chimney coming out of the ground most times when I see outdoor steel chimneys they exit the house through the wall above ground level.
 
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