Class A Chimney Pipe (Supervent vs Rock-Vent)

[Jacob Ressel]

I'm getting close to purchasing all the chimney and stove pipe for a new install wood stove, Alderlea T5. Install will be from main level and then directly through attic with a 30 degree bend to achieve a 31.25" offset. I need to move the roof penetration away from the valley. And following the 10/2 rule, I'll be about 6'-7' out of the roof.

My question is of cost and benefit analysis for the Class A chimney pipe. Roughly part for part, I have priced out Menard's Supervent and Rockford Chimney's Rock-Vent. The Supervent at Menards is roughly $1300 and the Rock-Vent is roughly $3300.

Mostly, the differences that I'm finding are: Supervent is 304 Stainless while Rock-Vent is 304L Stainless. Supervent has 1" insulation while Rock-Vent has 1.25" insulation. And finally Supervent has a 10 year limited warranty while Rock-Vent has a lifetime transferrable Warranty.

Should I spend the extra $2000? My budget is tight! However, from my reading on this forum for a long time, it is apparent that when installing a new chimney, to treat it as infrastructure and buy premium for the safety. Piece of mind would come with Rock-Vent likely. ha. However, is Supervent that much worse? $2000 worse?

They do each seem to have welded seams and 0.016" steel thickness ID. As I will only be installing once, the Supervent rings won't be much of a burden. My goal is for safety here. I'm willing to pay the $2000 to not have my children die in a fire. Keep in mind I might always be perfect when using the stove. I will harvest my own wood, but until I have enough built up and seasoned, I'll likely purchase seasoned wood for a year or two. I do have a moisture meter to measure a fresh split before burning. I have a heatpump HVAC and plan to use the woodstove at least over the weekends and on quite cold periods. It is not out of the picture to use the woodstove as often as I can for heat.

Why should I or not chose one over the other?

 

[begreen]

As long as the system is properly installed, both will provide long service. I'm not sure who makes the Rock-Vent chimney pipe, but I suspect it is Ventis, which is a very good pipe. Another good one is ICC Excel. There are others, but usually they are only sold to professionals and dealers. Here is a Ventis (sold under the Champion label) dealer for comparison:

6" Ventis Stainless Steel Class A Solid Fuel Components | Woodland Direct

Representing some of the most durable chimney products on the market, Ventis is at the forefront of modern chimney design and innovation. Each Ventis product is made the USA and comes with a lifetime warranty on nearly every product they make. When y

www.woodlanddirect.com

The actual difference in lifespan may have more to do with how the system is run and cleaned. For an alternative options, give this place a call and ask for Sean.

Wood Stoves, Fireplaces and Hearth Accessories | WoodStovePro.com

WoodStovePro.com offers one of the best selections of high quality fireplaces and hearth accessories from top name manufacturers in the hearth industry. Whether you need wood stoves, gas stoves, wood boilers, chimney pipe / venting pipe, fireplace glass doors, outdoor or indoor electric...

woodstovepro.com

To save a bit, use their galvanized chimney in the attic. The galvanized is just the outside jacket.

 

[Jacob Ressel]

As long as the system is properly installed, both will provide long service. I'm not sure who makes the Rock-Vent chimney pipe, but I suspect it is Ventis, which is a very good pipe. Another good one is ICC Excel. There are others, but usually they are only sold to professionals and dealers. Here is a Ventis (sold under the Champion label) dealer for comparison:

6" Ventis Stainless Steel Class A Solid Fuel Components | Woodland Direct

Representing some of the most durable chimney products on the market, Ventis is at the forefront of modern chimney design and innovation. Each Ventis product is made the USA and comes with a lifetime warranty on nearly every product they make. When y

www.woodlanddirect.com

The actual difference in lifespan may have more to do with how the system is run and cleaned. For an alternative options, give this place a call and ask for Sean.

Wood Stoves, Fireplaces and Hearth Accessories | WoodStovePro.com

WoodStovePro.com offers one of the best selections of high quality fireplaces and hearth accessories from top name manufacturers in the hearth industry. Whether you need wood stoves, gas stoves, wood boilers, chimney pipe / venting pipe, fireplace glass doors, outdoor or indoor electric...

woodstovepro.com

To save a bit, use their galvanized chimney in the attic. The galvanized is just the outside jacket.

It seems you are saying that the difference between the more premium (ventis or ventis like and excel or excel like) and the more budget (like supervent) is negligible?

I feel I should want the highest quality stuff, but what is the 2-3x difference in cost going toward? In the case I mentioned above?

 

[begreen]

No, there is a quality difference. A better product line will have more options and fittings to cover unique installs. Premium pipe may be tested to a higher rating to meet Canadian standards, parts may fit better, etc. That said, the Selkirk pipe of today is notably better than the product of 20 or 30 yrs ago. I was crossed with this decision in 2006 and decided to go with DuraTech instead of Excel. It's had 17+ years of service and is still looking good, inside and out.

 

[gruesome]

You should also price out duravent duraplus ; I found Home Depot prices (for the zinc-galvanized outer layer) to be significantly lower than from other suppliers, for whatever reason. It might even be cheaper for your installer to buy it from Home Depot than from his distributor.

 

[brenndatomu]

I've put up 3 supervent chimneys now, they are between 7 and 12 years old at this point, no issues.

 

[Jacob Ressel]

What about some of the discussions for the way great causes the material to expand and contract over time. Is there a significant difference between premiums' offering that are significantly more safer?

Also what about the 304 SS vs 304L SS?

My biggest concerns are safety.

 

[stoveliker]

Regarding safety I'd say to just look to what (ul) standards they are tested.
All the rest is longevity (e.g. alloy type and wall thickness). Chimneys need inspection anyway, every now and then, to ensure they are still in good shape (i.e. to catch deterioration due to age or misuse).

 

[begreen]

You should also price out duravent duraplus ; I found Home Depot prices (for the zinc-galvanized outer layer) to be significantly lower than from other suppliers, for whatever reason. It might even be cheaper for your installer to buy it from Home Depot than from his distributor.

DuraPlus is a budget, triple-wall chimney pipe with less insulation thus requiring a third wall. Its larger diameter makes it bulkier and a bigger hole in the roof. DuraTech is double-wall and a better compromise.

 

[gruesome]

Also what about the 304 SS vs 304L SS?

In my (limited, but non-zero) understanding in 'normal' use the 'L' low carbon steels behave better for welding; less carbon means there is less chance of 'precipitation' of chromium carbides in weld zones that would make the steel less corrosion resistant. Now, looking at figure 3 in https://www.ssina.com/education/corrosion/intergranular-corrosion/#:~:text=effects of IGA.-,Chromium Carbide Precipitation,could potentially sensitize the steel. , the question arises what happens if you run your chimney close to 1000°F for many hours.... Isn't even 304L with 0.03% carbon going to become sensitized?

 

[bholler]

In my (limited, but non-zero) understanding in 'normal' use the 'L' low carbon steels behave better for welding; less carbon means there is less chance of 'precipitation' of chromium carbides in weld zones that would make the steel less corrosion resistant. Now, looking at figure 3 in https://www.ssina.com/education/corrosion/intergranular-corrosion/#:~:text=effects of IGA.-,Chromium Carbide Precipitation,could potentially sensitize the steel. , the question arises what happens if you run your chimney close to 1000°F for many hours.... Isn't even 304L with 0.03% carbon going to become sensitized?

Nope it will be absolutely fine. But also no one runs their chimney close to 1000 for hours. Infact most chimneys never see that temp much at all

 

[gruesome]

Nope it will be absolutely fine. But also no one runs their chimney close to 1000 for hours. Infact most chimneys never see that temp much at all

Well, as much as I want to trust you, but are you saying that graph is wrong? Or is it just because 1000°F is not reached outside of a chimney fire? Would standard 304 stainless steel then also be ok?

 

[bholler]

Well, as much as I want to trust you, but are you saying that graph is wrong? Or is it just because 1000°F is not reached outside of a chimney fire? Would standard 304 stainless steel then also be ok?

Im saying I have 304 liners out that have had woodstoves running through them as main heat sources for 30 years and they are fine. I didn't look at the chart because I can tell you without question 304 holds up well when used for wood

 

[stoveliker]

If the point is to heat your home, then it's advisable to avoid 1000 degrees pipes in particular if it's for hours .. too much heat going up that way, rather than into the room ...

 

[Jacob Ressel]

I really love the discussion here. Thank you everyone. I really am thinking that the budget lines with minimum features, such as welded seams with UL certs, are the best decision in most situations. Perhaps longevity is a great value for premium, but I'm not looking for an extended to the max time here. 15 years give or take is fine for me.

I will ensure it is installed correctly. I will inspect it periodically. I do not have a very unique installation need. I will be sure to get a well known brand that will be around in the future.

If I were an installer as a profession, I can see the value in getting an easier system to install so it is less a pita.


It is likely I will go with supervent or equivalent.

 

[Jacob Ressel]

I have been a bit more research in the stainless steel used. According to some sources, the 304 stainless exterior used on higher end Class A chimney pipes, such as SuperPro (Selkirk), better withstands high humidity regions. I do live in southeast Missouri with really high humidy in the summer months. 430 SS exterior on SuperVent (Selkirk) is not recommended. It has a higher risk of corrosion and rust due to the high humidity. Yet, areas with moderate and less humidities should be fine with the 430, such as mountainous regions, central plains, etc.

I guess i'm going to look more into the 304 SS for superior Corrosion resitance to deal with my high humidity. Really i think I need Welded Seams for sure, and UL 103 (HT) - (Hight Temp HT would be better for chimney fire resistance, as they are tested at short intervals of very high temps, above standard UL103).

Also note, that even inside an attic, the lower corrosion protection of 430 ss and galvanized is not gonna work in the high humidity. I thought maybe I could save some money by using galvalume inside the attic, but because of the high humidity, it will have a shortened lifespan. This is according to researching online. Other parts of the country, these options would work well, yet southeast missouri has a really high summer humidy, aaaa loooot.

I definitely have to say that I was likely going to purchase SuperVent by Selkirk, however the pipe from Shasta Vent seems great. I understand it is made in China though. I see this forum has talked about it in the past, but not lately.

Shasta Vent has 304 SS inside, outside, and the rings are 304 SS. It is UL103 (HT). The install instructions are fantastic as well. It does have a lifetime limited Warranty that can only be accessed if the system was installed by a professional, however.

It seems to be close to the pricing of SuperVent from Menards, when Priced on northlineexpress.

 

[begreen]

I thought maybe I could save some money by using galvalume inside the attic, but because of the high humidity, it will have a shortened lifespan.

This is overthinking things. I have a 13 yr old galvalume DuraTech chimney on the greenhouse stove. It's out in the weather and doing fine. I don't think I have ever seen a chimney outer skin rot inside of an attic from humidity.

 

[brenndatomu]

overthinking things

X2!!

 

[gruesome]

Just a few pics of the galvanized Duravent Duraplus after a few months with a few heavy rains, and of a stainless steel double walled Solo firepit after a few years in the same environment, just to show that stainless steel is not necessarily stainless.

The Duraplus seems crimped and riveted, not welded, at least for the outer two layers. I worried the chimney was starting to corrode at the bottom end, but it was just creosote washed down from the chimney cap, and cleans off easily. (After two months of burning not-quite-dry wood I cleaned out 1/2 cup of creosote from the chimney, and about 1 1/2 cups from the stove pipe, and switched to drier wood.)

The Solo firepit, advertised as stainless steel, definitely has a lot of surface corrosion, but so far it doesn't seem to rust into the material. Still, not quite 'stainless'. Interestingly, what I believe to be the weld zone of the outer shell shows less corrosion.

 

[Jacob Ressel]

Just a few pics of the galvanized Duravent Duraplus after a few months with a few heavy rains, and of a stainless steel double walled Solo firepit after a few years in the same environment, just to show that stainless steel is not necessarily stainless.

The Duraplus seems crimped and riveted, not welded, at least for the outer two layers. I worried the chimney was starting to corrode at the bottom end, but it was just creosote washed down from the chimney cap, and cleans off easily. (After two months of burning not-quite-dry wood I cleaned out 1/2 cup of creosote from the chimney, and about 1 1/2 cups from the stove pipe, and switched to drier wood.)

The Solo firepit, advertised as stainless steel, definitely has a lot of surface corrosion, but so far it doesn't seem to rust into the material. Still, not quite 'stainless'. Interestingly, what I believe to be the weld zone of the outer shell shows less corrosion.
View attachment 327375View attachment 327376View attachment 327377View attachment 327378

great photos. thanks!

This thread just continues to refute the need for premium chimney pipe.

 

[begreen]

great photos. thanks!

This thread just continues to refute the need for premium chimney pipe.

When faced with this question back in 2006 we were concluding a major project and funds were getting tight. I balanced the pros and cons between Excel and DuraTech. Ultimately new oak floors won out and we put in DuraTech. It's done well so far. It wasn't the cheapest, I think Selkirk was at the time, but I had leak problems with some old Selkirk due to water traveling down the seam and didn't want to repeat the experience.

 

[gruesome]

great photos. thanks!

This thread just continues to refute the need for premium chimney pipe.

Oh, ok, be careful there; the chimney pipe in my pics has been exposed to the exceedingly harsh climate of southern California for all of four months (it did rain though; that song title is just a lie). I wouldn't want anybody to over-interpret my pics. I just didn't see myself spending more than a few hundred bucks for an outdoor hobby (man cave? man yurt?) installation that tries to heat the great outdoors of Orange County.

After looking again at my not quite smokeless not quite stainless fire pit, I actually fired off an email to Solo customer service, inquiring about the type of stainless they are or were using (the pit is from 2022). I'll update this if/when I hear back.

Update: Solo Stove answered really quickly: "[...] This is a common pattern in 304 stainless steel reacting to the intense heat generated inside your fire pit, but it doesn’t affect its performance. [...]"
Actually, I think I can guess what happened: they used non-stainless wire brushes to create the brushed finish, and in the process managed to embed some extra iron in the surface grooves (note the horizontally elongated surface corrosion pattern). In the weld area they removed more material, or maybe the material is slightly thicker, or the thermal conductivity is slightly worse.

I should also add that the outer surface of the Duraplus stays completely cool. It doesn't even get to skin temperature.

 

[bholler]

great photos. thanks!

This thread just continues to refute the need for premium chimney pipe.

The need for? No cheaper pipe has to pass the same safety tests as the expensive stuff does. But the cheaper stuff doesn't have nearly the options or fit and finish of the better stuff. And the better stuff generally allows for better difference in expansion between the inner and outer walls

 

[gruesome]

Oh, ok, be careful there; the chimney pipe in my pics has been exposed to the exceedingly harsh climate of southern California for all of four months (it did rain though; that song title is just a lie). I wouldn't want anybody to over-interpret my pics. I just didn't see myself spending more than a few hundred bucks for an outdoor hobby (man cave? man yurt?) installation that tries to heat the great outdoors of Orange County.

After looking again at my not quite smokeless not quite stainless fire pit, I actually fired off an email to Solo customer service, inquiring about the type of stainless they are or were using (the pit is from 2022). I'll update this if/when I hear back.

Update: Solo Stove answered really quickly: "[...] This is a common pattern in 304 stainless steel reacting to the intense heat generated inside your fire pit, but it doesn’t affect its performance. [...]"
Actually, I think I can guess what happened: they used non-stainless wire brushes to create the brushed finish, and in the process managed to embed some extra iron in the surface grooves (note the horizontally elongated surface corrosion pattern). In the weld area they removed more material, or maybe the material is slightly thicker, or the thermal conductivity is slightly worse.

I should also add that the outer surface of the Duraplus stays completely cool. It doesn't even get to skin temperature.

Jeez, 200 minutes time limit for editing...
I was in the process to add that they might also have done a local after treatment to the weld zone on the Solo firepit, to remove free iron.
And the outer wall of the Solo gets super hot, very much unlike the Duraplus chimney pipe.