Seeking Guidance on 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.

Jamie Hall

Slightly puzzled. Is that upper picture -- bare concrete wall with the square hole in it -- the new work? And then the brick with a door frame on it also new?

What we really need to know is what is the flue inside that chimney that that connects to? Having that six inch square opening kind of restricts what you can do with the chimney in the future, however.

For the moment, if it were mine to play with, I'd just install the door on that frame, if that's new work, and I'd put a screen on the top of the flue. Then later, when and if someone decides to use it for something, they can install and mortar a thimble in there if need -- or if the flue is bigger than the opening, and they want to connect something bigger (like a big wood stove?) they can enlarge the opening as needed.

Bob Harper

Building and rebuilding chimneys is not a DIY project. Leave it to the pros. Nobody can teach you how to do this online. What you do need is a professional Level II inspection, which will determine what will be needed to make the repairs. Keep in mind the chimney will need to be relined to be used. As noted, the expense of making these repairs might be better served by putting it towards high efficiency equipment that does not need a chimney. However, if you're contemplating a wood, gas or pellet stove, they each have their own special venting requirements. See your local chimney pro.