Metal-Fab Chimney

[Wilbursan]

I'm having a house built and I noticed this evening when I stopped by that the chimney was installed. I hadn't even realized they had installed it yet. They are building so fast I can't keep up. Anyway, the chimney is a Metal-Fab TG MAX chimney, 6x36. The part number is 6TGG36 which their website says is Galvanized and the label says "2100 DEG GALV" so that seems to confirm it. Supposedly rated at 2100 degrees intermittent and 1000 degrees continuous. Also from the website: "The S.S. flue conduit is wrapped with ceramic insulating material". So this means it is double walled and insulated correct? (I can't see the ends of the pipe, it's all assembled).

 

[valley ranch]

Hi, I haven't been able to find product reviews on that chimney. I'm sure it's been tested like the stainless I've installed. I'm sure it will do well.

However I think nothing beats a well built masonry chimney. Nether of us has one that't the funny part.

 

[bholler]

I am assuming that the chimney is going in a chase/ If not i fell that they should have used stainless exterior stuff as well. But yes it is standard class a chimney with stainless inner liner insulation and then the outer shell. While i agree that a properly built masonry chimney with an insulated stainless liner will last much longer if it is maintained. The price difference makes up for that difference in durability very easily.

 

[fire_man]

However I think nothing beats a well built masonry chimney. Nether of us has one that't the funny part.

Interesting comment. Most of the local sweeps I have spoken with wish pure masonry chimneys were banned at least for woodstove usage. They claim they have seen numerous problems (such as structural issues, inadequate clearance to combustible, and performance/draft related) and usually recommend SS lined/insulated masonry chimneys. I suppose you did qualify by saying "well built", but that still does not address the draft/insulation issue.

 

[valley ranch]

A properly built masonry chimney is best. No need to gild the lily.

Richard

 

[BCC_Burner]

A properly built masonry chimney is best. No need to gild the lily.

Richard

Just like the steam engine and single pane windows are the best for daily commuting and thermal efficiency.

 

[bholler]

A properly built masonry chimney is best.

In what way is it best? They generally do look better i will give you that. And with proper maintenance thay will last a very long time. But as far as performance they are far worse unless there is an insulated ss liner in it. And after you build a masonry chimney and put a liner in it it will cost way more than a prefab. Not to mention the fact that a prefab can go in in a day. To build a masonry chimney and line it is at minimum 2 days usually at least 3. All that being said i have 2 lined masonry chimneys one was existing that i lined and one i built. But labor cost was not a factor for me.

 

[Wilbursan]

I am assuming that the chimney is going in a chase/ If not i fell that they should have used stainless exterior stuff as well. But yes it is standard class a chimney with stainless inner liner insulation and then the outer shell. While i agree that a properly built masonry chimney with an insulated stainless liner will last much longer if it is maintained. The price difference makes up for that difference in durability very easily.

How often will a galvanized Class A chimney need replacing typically? 10 years, 20, 30?

 

[bholler]

How often will a galvanized Class A chimney need replacing typically? 10 years, 20, 30?

That depends on lots of things if it was exterior i would say probably 10 to 15 years. If it is in a chase 25 to 30 years if not more. Now if it is abused it can really shorten the life but that is the same with anything.

 

[webby3650]

How often will a galvanized Class A chimney need replacing typically? 10 years, 20, 30?

I see lots of galvanized pipe around here. Many of them are approaching 40 years old, with little to no rust. Some have been painted and they don't look too bad.
I would prefer SS personally, but it doesn't seem like too big of a deal.

 

[webby3650]

A properly built masonry chimney is best. No need to gild the lily.

Richard

I hope visitors to this site don't see this and believe it to be true. This is a personal opinion. Other than looks, a class A chimney outperforms a masonry chimney in almost every way.

 

[valley ranch]

I know some people are very emotional about this and get very angry but there can be other truths than what you would like to permit. I know of chimneys that work very well and I would prefer them to a triple walled metal pipe alone. I also have seen that there is no absolute need for a metal pipe to be shoved down a good Masonry Chimney.

Visitors can decide their own advantage without silencing everyone who doesn't agree with the "only way it can and should be done."

I say this respectfully and hope I'm not jeopardizing my membership on this forum.

Richard

 

[HotCoals]

Open fire places needed a bigger flue. Today's wood stoves,not so much.

 

[bholler]

I know some people are very emotional about this and get very angry but there can be other truths than what you would like to permit. I know of chimneys that work very well and I would prefer them to a triple walled metal pipe alone. I also have seen that there is no absolute need for a metal pipe to be shoved down a good Masonry Chimney.

chimney will out preform and outlast that clay liner in just about every situation. I am sorry if that offends you but it is the truth and i doubt that many here would disagree with me

Ok I am not emotional or angry but first we are talking about class a chimneys not triple wall they are totally different things and no triple wall usually doesn't preform that great. And yes clay lined masonry can work just fine if it is sized correctly but and insulated stainless liner or class a. Also i am not saying that you should line a perfectly good clay lined chimney that is sized correctly is working good and has proper clearances. I am talking about new construction which is what the op is doing and in that case i would not put in a clay lined chimney unless it was for a coal appliance.

 

[begreen]

I have to side with the extensive commercial experience here. They are looking at dozens of chimneys every year. No one is saying a good masonry chimney can't perform well. But all too commonly it is assumed that the masonry chimney is sized correctly for the stove and installed right, often it is not. And very often people burn using a chimney out of blind ignorance. In my younger days I did likewise. Ran a VC Resolute into an unlined old chimney and ran it that way for a few years. Thankfully nothing happened, but the potential for an issue was huge. This was long before hearth.com.

The problem with masonry chimneys is that very often they are built or installed wrong, their liners can be fragile and they are sized for a different task then venting a modern stove with a 6" flue. Many masonry chimneys are ticking time bombs that foster pyrolysis over time. You don't know there is an issue until you smell smoke, if you are lucky. Also, masonry chimneys are particularly vulnerable in earthquake prone areas. Another issue is that they are uninsulated. If the chimney is exterior it can perform poorly, backdraft and build up creosote quickly. A metal flue system properly installed gets around these issues. It is going to be inherently safer, more efficient and easier to clean.

This masonry chimney install went for decades with a wood stove connected to it. It was pro-cleaned every season. Guess what they found when sparks started falling on the bed last winter?

 

[fire_man]

The construction of a masonry chimney is kind of wacky if you think about it. You have a bunch of heavy clay liners stacked on top of each other, freestanding to sometimes really tall heights and held together with a little cement. The clay can develop cracks and the liner segments can shift without knowing until it's too late.

Even a properly built masonry chimney seems more precarious to me than a SS lined system.

 

[BrotherBart]

(broken image removed)

 

[fire_man]

I think BrotherBart's chimney needs a little repointing!

 

[BrotherBart]

I think somebody used a really stiff chimney brush.

(Actually an earthquake caused that one.)