curious if it has been done and how it worked out-replace top portion of brick chimney with SS

PeteA

I have not embarked on this project but I am always looking at different ideas (especially as I get older) to eliminate weak spots or failure points where possible.
I am wondering if it's possible to remove the portion of the chimney that rises up through the roof down to inside the attic and then pick up the portion in the attic with stainless or some other approved long lasting pipe out through the roof. I do understand that the opening of the roof will need to be reconfigured to properly support and seal around the new pipe and I know its critically important to seal from the liner inside the old chimney to the new pipe (I've seen stainless transition pieces made at various fireplace websites but that doesn't mean it works in this application) and also I would also recap and seal around the brick to the liner and the new pipe. so I am not assuming it's an easy job but just curious if it is possible and if anyone knows of any photos posted of someone's completed similar project.
Thanks
Pete

leonz

Fix the chimney, the stainless will fail in 9 years. Been there, done that.

EBEBRATT-Ed

have the chimney rebuilt from just under the roof line. It will last a lot longer if done right

Jamie Hall

As noted, stainless -- or any metal -- will fail in a few decades. One of the chimneys I care for was built of brick in 1780, and I'll grant you that it did need repointing a decade or so ago... but that's all its needed.

Now I'll grant you that it really is brick, and not concrete dyed red... I don't really know how long modern "brick" will last. A century, maybe?

ChrisJ

leonz said:

Fix the chimney, the stainless will fail in 9 years. Been there, done that.

Why did the stainless fail in 9 years?

PeteA

Wow
thanks for the info. I had no idea that the steel would perform so poorly. I figured that is what everyone is installing metal liners that the steel must last a lifetime 

KC_Jones

No one has asked the most important question with respect to masonry and stainless.

@PeteA what type of appliance is connected to this chimney?

PeteA

@KC_Jones

The chimney is the vent for my gas boiler and a gas hot water tank.
no fire places or other connections

KC_Jones

PeteA said:

@KC_Jones

The chimney is the vent for my gas boiler and a gas hot water tank.
no fire places or other connections

Combustion gases from natural gas appliances eat masonry chimneys. The previous recommendations to keep the masonry are not sound. If you are having problems, you can rebuild the chimney, but a stainless liner is the recommended fix, and strongly recommended all the time on this very website. Either that or a complete tear out and replacement with B vent, which is my personal plan for the near future. @ChrisJ had this done in his own house.

Jamie Hall

Then it should have a liner. The strong acid in the condensed combustion gas from a gas appliance is not friendly to mortar. You expect the liner to last about as long as the appliance. You can expect the brick chimney to last for a couple of centuries.

ChrisJ

Yes, my 1860s chimney was torn out and replaced with a B vent.

Honestly, I'd like to hear from @Bob Harper on this subject.
He knows more about this subject than most.

ethicalpaul

Thanks for clearing that up, I was about to rip out my SS liner to restore the original everlasting brick flue!

https://www.youtube.com/watch?v=PQi4EJrCNr4

PeteA

Jamie Hall said:

Then it should have a liner. The strong acid in the condensed combustion gas from a gas appliance is not friendly to mortar. You expect the liner to last about as long as the appliance. You can expect the brick chimney to last for a couple of centuries.

Yes the chimney does already have a ceramic liner which would stay in place.
i was just curious about removing the brick and liner segments into the attic area and then coupling back onto the liner/brick in order to extend stainless B vent up back out the roof.
i assumed that the SS was lifetime but I guess not.
it was just an idea I was bouncing around, that’s all. My current chimney is about 100 years old so I am sure it will need pointing and a cap soon so I was just checking for lower maintenance options.

mattmia2

The brick fails either because the chimney is leaking at the top cap or the combustion products are condensing in it. If it is done properly and maintained a modern brick chimney is very durable. Metal vents are installed now because they are much cheaper.

I don't think a gas appliance inherently needs a metal liner, gas appliances installed in the 50's and 60's seem to do fine, I think it has to do with the draft not being set up right but I'm not an expert on this part.

If the chimney is 100 years old I would look carefully in to the bottom or middle of it before concluding it has a clay liner, clay liners weren't common at that time but it is common to have used a liner when rebuilding a damaged top portion of the chimney.

leonz

ChrisJ said:

leonz said:

Fix the chimney, the stainless will fail in 9 years. Been there, done that.

Why did the stainless fail in 9 years?

Wood and coal flue gasses.

MikeAmann

I am currently working on Mom's chimney.
Check this out: https://heatshieldchimney.com/chimney-liner-repair-systems/#:~:text=To repair chimney interiors, one,defects in tile lined flues.

https://fluetechinc.com/flue-repair-and-lining-systems/

https://www.rockfordchimneysupply.com/pages/rigid-liners