Hi , i am new to the forum and have a chimney question. I recently had a chimney fire and have several cracks in the original tile flue. The insurance company says to put in a insulated ss liner. anyway the liner is not the problem i am wondering if any one has used the vermiculite/cement insulation. This is a wet solution and I am wondering how much of a problem it is to pour? thanks for any advise... paul
Chimney liner insulation ?
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ikessky
Minister of Fire
From what I've read, it's more of a consistency of dirt rather than a liquid. I don't think it's hard to pour at all.
You actually have to mix it with water BEFORE you pour it down the flue...
It's kinda "clumpy" like cat litter, & after it gets all packed down around the liner, it kinda forms
a concrete-like substance...
It's kinda "clumpy" like cat litter, & after it gets all packed down around the liner, it kinda forms
a concrete-like substance...
potter
Feeling the Heat
What's the name of this product? Mines currently not insulated and was thinking of doing it this summer....
potter said:
THERMIX is what we have...It's about 40$ per 42 lb bag = 3.25 cu ft of insulation
Calculation formulae:
(WxDxH) - (ACSxH)
________________
5616
Where:
W=width of flue opening in inches
D=depth of flue in inches
H=height of flue in inches
ACS=cross sectional area of the chimney liner
ACS values for ROUND liners(sq in)
5" - 19.62
6" - 28.46
7" - 38.46
8" - 50.25
Hearth math 101!
ikessky
Minister of Fire
Can I ask what the calculation is figuring out? How many bags you will need? I ran the numbers just because I was curious and came up with ~.8
ikessky said:
The first half of the numerator is the volume of your terra cotta tile (WxDxH)
The second half is the volume of your liner(ACSxH)
The denominator is the volume of a bag of THERMIX in cubic inches (3.25 Cu Ft x 1728 Cu In /Cu Ft)
Let's take an example...(rough calculations only)
8x12 flue - 15ft high with a 6" liner
An 8x12 flue tile is actually more like 6x11 inside , so:
6x11=66x180 (15ftx12in/ft0 = 11880
ACS for 6"=28.46x180=5122.8
11880-5122.8=6757.2
6757.2/5616=1.203
So you'd need 1.2 bags of Thermix for this installation
My head is starting to hurt...hope this makes sense!
LeonMSPT
Minister of Fire
It's not your only option... and an installer I know doesn't care for the poured in insulation.
He'd rather apply the insulation to the liner before, or as he installs the liner. A blanket wrap with a stainless mesh net to protect it and retain it as it's slid into the chimney. His reasoning is that there is no way to assure that the liner is centered in the flu when you pour the insulation in. They've busted out some of the poured in jobs and redone them. The liners were pressed against the side of the flu when it was poured and there were areas where the insulation was near zero against the side of the flu and there were hot spots in the house.
A zero clearance insulation system is available that will assure this doesn't happen. I've done two this way and had good results with them. Never used the poured in system, can't speak personally for the outcomes, only passing on what I was told.
He'd rather apply the insulation to the liner before, or as he installs the liner. A blanket wrap with a stainless mesh net to protect it and retain it as it's slid into the chimney. His reasoning is that there is no way to assure that the liner is centered in the flu when you pour the insulation in. They've busted out some of the poured in jobs and redone them. The liners were pressed against the side of the flu when it was poured and there were areas where the insulation was near zero against the side of the flu and there were hot spots in the house.
A zero clearance insulation system is available that will assure this doesn't happen. I've done two this way and had good results with them. Never used the poured in system, can't speak personally for the outcomes, only passing on what I was told.
happyjack said:
oconnor
Minister of Fire
Not only is Thermix not the only options, but some liners don't permit it - in the end, you need to follow the liner manufacturers instructions for insulating the liner. Other methods will work, but the only one your insurance company will want to see is the one your liner manufacturer has specified - given it is your insurer who wants the insulation, this finer details is one you should likely pay attention to.
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