Rebuilding Chimney Conduit after Foundation Repairs

[jmbinette]

Hello fellow homebuilders/renovators,

I recently had to repair some foundation cracks in my home, which required the removal of a 10-foot brick wall in the basement. As a result, I need to rebuild the wall and, more importantly, reinstall the chimney conduit properly. I have two chimneys in my house—one on the ground floor and the other in the basement.

The chimney in the basement is a bit unique, as it consists of a square 6x6 hole formed and poured into the foundation. The original setup involved sliding a round 6-inch metal pipe into the brick wall. Now, after the foundation repairs, I want to rebuild the wall without necessarily reconstructing the entire brick structure.

I am seeking guidance on how to properly install the chimney conduit, and I would like to make the setup energy-efficient, considering that I may not use the basement chimney in the short term. Here are a few specific questions I have:

Chimney Conduit Installation: Should I use a wall thimble for the chimney conduit installation? What are the best practices for ensuring a secure and durable connection without compromising safety?

Sealing and Insulation: What recommendations do you have for sealing and insulating the chimney conduit to prevent any future water infiltration or air leaks? I want to ensure energy efficiency and protect against potential issues in the long run.

Future Use Considerations: While I may not use the basement chimney immediately, I want to build it right for potential future use or for the next owner. Are there any specific design elements or precautions I should take to make it easier for someone to use the chimney down the line?

If anyone has experience with similar situations or has expertise in chimney installations, I would greatly appreciate your insights. Additionally, if you have any pictures or examples of similar projects, they would be immensely helpful.

Thank you in advance for your time and assistance. I look forward to hearing from the knowledgeable members of this community.

 

[begreen]

I am seeing what looks like the cleanout door below and the thimble up above it. The chimney conduit is normally called the flue. Is the current flue tile lined?

What is the area of concern, the cleanout, the thimble, or both? What is the plan for finishing this area? Does it involve combustibles like wood studs?

 

[jmbinette]

I am seeing what looks like the cleanout door below and the thimble up above it. The chimney conduit is normally called the flue. Is the current flue tile lined?

What is the area of concern, the cleanout, the thimble, or both? What is the plan for finishing this area? Does it involve combustibles like wood studs?

Hi,

The current flue is not lined, only a square tube 6x6. This is what you see with mineral wool inside it.
My original plant is to frame with 2x4 and insulate the wall. Then put a drywall finish.

I am wondering how to install the thimble for the flue and also for the cleanout door

 

[begreen]

To be usable, the chimney would need a 6" insulated, stainless steel liner. 6" x 6" conduit thru raw brick is not much good for a wood stove flue, but might work for a 4" gas or pellet stove vent.

Passing through a wall will depend on what is connected. Wood stoves venting needs the most protection, especially through a stud wall.

Chimney info - CHIMNEY - PASSING A CHIMNEY THROUGH THE WALL

DON’T Just “Do it” - Placing a wood stove into an existing masonry chimney could be hazardous to your health and house. Read this to learn more. One of our biggest problems occurs when a customer enters the shop and states “I have an existing woodstove into a masonry chimney - I’d like to...

www.hearth.com

 

[jmbinette]

Thanks,

Actually the flue will go through drywall+wood and then throught concrete (foundation)
I will look into stainless steel liner/thimble.

Is there a similar product for the ash clean out door ? I mean to go through drywall/framing