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Chimney troubles

Dmbfan07032 Member Posts: 3
I have a question about chimney service I am receiving.

I was recently told I need to have my chimney relined. This work needs to occur on the furnace side of the chimney.
It’s the original chimney, the house is about 100 years old. I agreed to all of this since the guy opened the duct work in the basement and proclaimed I needed a liner. Didn’t look in the chimney. Didn’t use a camera.

So, I went along with all of this and work began on Saturday.

When they opened up the outside of the chimney, I was told right away that the wall in between the two was no good/thin and needed replacing. To make that repair, they would place my liner and then fill around it with concrete.
Does any of this sound normal/appropriate? I would be grateful for any insight you might provide.

Thank you in advance.


  • Jamie Hall
    Jamie Hall Member Posts: 23,433
    Could be... one would have to look at the chimney to tell.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • Dmbfan07032
    Dmbfan07032 Member Posts: 3
    Thank you...cement around the liner sounds weird to me. Makes me think a future replacement would be incredibly difficult. Contractor says the stainless steel should never need replacing.
    HVACNUT Member Posts: 5,863
    I'm not a chimney guy, but have recommended liners to clients.

    There are many types of cement. I wouldn't think it was a standard mortar or sand mix but an approved light weight insulator mix of some kind. You would need to clarify that.
  • JohnNY
    JohnNY Member Posts: 3,231
    edited April 2020
    Chimneys are tricky and I'm willing to bet this work, on a 100-year-old home, is necessary. Make sure you're getting a top quality stainless steel liner and you'll do this work once in your lifetime. That said, yeah, a good chimney contractor drops a camera down the structure to inspect the walls. Anyway, brick and mortar in this application doesn't last forever. If it's not a tremendous financial burden, be happy you're doing a complete job.
    Contact John "JohnNY" Cataneo, NYC Master Plumber, Lic 1784
    Consulting & Troubleshooting
    Heating in NYC or NJ.
  • Bob Harper
    Bob Harper Member Posts: 1,040
    You are supposed to have a Level II inspection prior to relining. That guides the scope and process. In the case where the wythe wall separating flues is missing or failing, yes, that needs to be addressed. What they probably meant was a cementitious liner insulation. The original Ventinox ss liner from 1980 used Thermix, which is a lightweight insulating concrete. It has a k factor of 0.43/ inch and typically provides a zero clearance rating for woodburning (2,100F) as long as you have a nominal 4" outer wythe wall, which is why you need to do the level II inspection. Just make sure of the sizing. You must derate 20% for corrugated liners plus additional derating for offsets. A smoothwall liner is exempt from the 20% off the top. Most ss liners carry a lifetime warranty and most of those are transferrable. Demand a warranty card. This will require an annual inspection to maintain the warranty.
    EBEBRATT-Ed Member Posts: 15,616
    Yes that is commonly done. The liner lines the chimney. They must have some question about the chimney's structural ability and the concrete will stabilize that
  • Dmbfan07032
    Dmbfan07032 Member Posts: 3
    I thank all of you for the input.

    It’s hard to know when someone is just stringing you along to create more work and money, or when there is an honest need for work to be done.