I am trying to line a 7"x11" chimney flue with a 6" round flex liner. Unfortunately the first time I tried to drop the liner down I only was able to get 2' in before it would not go any farther due to misaligned bricks. A friend of mine made me a cone out of wood 6-1/4" at the widest to pull the liner down with. I tested just the cap out today and was able to navigate the curve in the 30' chimney, however I was not able to get it all the way down due to the cement connecting the liners sticking out. Any suggestions for how to run the liner?
Lining 7"x11" chimney flue with 6" liner
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In the long(ish) run, it may be cheaper, given the increased labor costs, and a lot less messy and destructive to use a poured in place liner. Guardian, Supaflu and Ahern(?) are three brands - there may be more. You'll take a loss in selling the liner you already have, but this may be preferable to breaking out the present liner, etc.
fraxinus said:
Looks like a neat idea, hadn't seen that before. I'm guessing a poured in place liner may not be a good way to go this time of year, though. Concrete doesn't cure well at some of the temperatures the OP is getting now...
The flex liner will be ovalized, so make sure it is oriented the correct way to maximize space with the longest part of the oval in the 11" direction. Stuff something into the tip of the liner like an old pillow with about a 6" radius sticking out. Wrap it all with duct tape, making a makeshift cable pull. Never tried it but it looks good on paper.
JV_Thimble: I'm not positive, but I don't think cold weather would prevent installing a poured liner. Portland cement is an ingredient, but the mixes used contain other ingredients and solidify very quickly - no more than 48 hours from start of intallation to being able to use the chimney, at least for Supaflu. Two addresses: http://www.guardianinc.com http://www.supaflu.com
I was thinking about trying to ovalize it with a piece of wood and a hammer, if I turned it into a more oval shape I think I could be able to get a 6" liner down the 7"x11" chimney.
My insert needs a 6" connections so I don't want to go smaller than that.
Pouring a liner sounds expensive, especially since it's a 6" liner and the chimney should be 7" width.
Thoughts?
My insert needs a 6" connections so I don't want to go smaller than that.
Pouring a liner sounds expensive, especially since it's a 6" liner and the chimney should be 7" width.
Thoughts?
I know for the supra-flue poured liner they want 1" thick minimum to pass UL testing (I think it was UL1777). Otherwise you will just be reducing the size without any safety benefit.
In fact, has your flue passed a Level II inspection by a certified sweep? This would involve checking all accessible areas to verify proper construction and clearances to the masonry structure. Also checking the integrity of the flue tiles top to bottom. With the sloppy work of mortar squeezing out all over I doubt it will pass.
By simply dropping a 6" SS liner down you are not really increasing the safety of the system, you can assume the SS will be resting against the clay tiles in many spots. Metal transfers heat very well. You can see where I am going. For the liner to have 0" clearance to the clay and the masonry to have 0" clearance to combustibles the SS liner needs to be properly insulated as per the mfg specs (usually a 1/2" wrap of special insulation meets the requirements). To accomplish this on a 7" x 11" ID clay flue we ovalize to 4" on the skinny side with a tool we have, then wrap in insulation.
In fact, has your flue passed a Level II inspection by a certified sweep? This would involve checking all accessible areas to verify proper construction and clearances to the masonry structure. Also checking the integrity of the flue tiles top to bottom. With the sloppy work of mortar squeezing out all over I doubt it will pass.
By simply dropping a 6" SS liner down you are not really increasing the safety of the system, you can assume the SS will be resting against the clay tiles in many spots. Metal transfers heat very well. You can see where I am going. For the liner to have 0" clearance to the clay and the masonry to have 0" clearance to combustibles the SS liner needs to be properly insulated as per the mfg specs (usually a 1/2" wrap of special insulation meets the requirements). To accomplish this on a 7" x 11" ID clay flue we ovalize to 4" on the skinny side with a tool we have, then wrap in insulation.
I had a similar situation. I ovalized a 6" down to under 5" using the 2x10 technique though found a 2x4 was easier. The rise is 24' and I ovalized down to 4" to get through a fireplace damper. The draft is great and I don't think the change in shape of the pipe and a very big impact.
Ovalizing is fine within reason. There are two things to look out for. 1. Dont ovalize it too much or you will kink the liner, and 2. maybe separate the seams. When i was talking about ovalizing, mine came that way due to it being shipped coiled up. The other thing i found is it is a little harder to sweep because of the smaller cross section in one direction.
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