Installing a Shaped Chimney Liner with Insulation
February 24, 2026
Sometimes a standard round chimney liner just won’t fit down your flue, and that’s okay. At Rockford, we have smart alternatives and the technical support to guide you every step of the way.
If the properly sized round liner won’t fit, explore our rectangle, oval, and square chimney liners & insulation blanket kits. We’ll help you choose the right shape and size to maintain proper draft and meet UL 1777 insulation requirements. You can also use our Chimney Liner Size Calculator Guide
Our friend Mark at Gunflint Designs recently installed an insulated rectangle chimney liner for his wood burning furnace and created a helpful video that answers many common installation questions.
Still unsure which option is right for you? Reach out, we’re always happy to help!
Shaped Chimney Liners & Insulation:
Conversion Charts:
Chimney Liner Conversion
Insulation Conversion
Rectangle Liner Insulation Sizing
Square Liner Insulation Sizing
Helpful Tools:
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Our 316Ti flexible chimney liner and chimney liner components have passed the rigorous testing at the Underwriters Laboratories with best in class status and are UL Listed. So if you are looking for UL listed chimney liner sold directly to homeowners, then look no further than Rockford Chimney
