Putting in my smooth wall 20' liner as soon as thermix arrives. Has anyone used this and is this going to make liner replacement impossible in future? I have a 7×7 clay tile with a 6" liner, so wrap insulation is not an option.
insulating liner with thermix?
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We use it all the time and yes you can pull the liner out if you are talking about the double layer smooth wall stuff you will probably have to unravel it out of the chimney if need be. But honestly with that liner in a 7 by 7 you will have no where near enough insulation to be effective and you may even have trouble getting your liner in there
JA600L
Minister of Fire
I have similar questions. My flue is a 7x12 and a local stove shop put a 6" liner in it. I was told it was a tight fit. Should I bother trying to put a product in there to insulate atleast the sides of the liner?
It can help but it will not give you the zero clearance to combustibles it is supposed to because you will not have enough thickness
JA600L
Minister of Fire
What is the zero clearance about? This is an outside chimney with the clay liner still in tact and inspected to be good still.
I am mainly interested in providing the chimney with a better draft. My first thought is to drop Roxul in there, but I have seen other posts where people were told not to do it.
I am mainly interested in providing the chimney with a better draft. My first thought is to drop Roxul in there, but I have seen other posts where people were told not to do it.
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To meet code your chimney needs 1" of clearance from the outside on the masonry to any combustible materials. If you have this then you are in good shape if not you do not meet code
Even a properly insulated liner would not fix that the insulation is only designed to work with 4" nominal masonry between the outside of the insulation and the combustibles if it was just the clay liner there would still not be enough protection.
JA600L
Minister of Fire
Actually it is. This flue runs east and west. The house faces north and south. This is a complete outside chimney with 3 flues. It is built very well (house built in 77') and thick enough that the flues are not near combustables. I only use one other flue for the occasional fire upstairs . The liner is centered in the flue.
They it should be ok. Technically it would not meet code but you should be pretty safe
JA600L
Minister of Fire
yes I think it will help quite a bit. It wont be quite as good as if you had it insulated totally correct but it will still help
JA600L
Minister of Fire
Which product would you recommend using for this job? I am close to a lot of box stores and masonry places. Sorry for all the questions. I realize this was not done in the correct way professionally but I would like to do things right from here.
At this point your only option really is thermix or some other ul listed chimney insulation mix there are quite a few brands out there
Wisneaky
Minister of Fire
Not all liners are the same. My Duraliner is rated zero to combustibles and can sit next to wood or masonry with no clearance needed. Even when I have internal flue temps of 600 degrees I can hold my hand on the outside and it is barely warm.
It absolutely can not sit next to wood it needs the 4" of masonry between it and the combustible materials. It is an insulated liner not an insulated chimney and even those need 2" clearance to combustibles. But yes it does have zeroclearance to the masonry and then zero clearance from the masonry to wood with no additional insulation
Wisneaky
Minister of Fire
Hello it may be to late but ..Do Not use the Thermix...
If you do not remove the tile liner you will not really be able to get much thermal in at all anyway. If you do remove the tile liner you will have plenty of room to wrap the liner with a 1/2 insulation wrap. Thermix cannot be cantered around a chimney liner so its a unprofessional installation.
Thanks
If you do not remove the tile liner you will not really be able to get much thermal in at all anyway. If you do remove the tile liner you will have plenty of room to wrap the liner with a 1/2 insulation wrap. Thermix cannot be cantered around a chimney liner so its a unprofessional installation.
Thanks
I dissagree totally it can be done professionally if you know how and in some situations it is the right solution.
kennyp2339
Minister of Fire
I like the idea of the thermix, but what happens if you have a chimney fire or the cap rips off the liner and you have to replace the whole thing? doesn't the thermix set up like concrete?
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