How clean should a chimney be before a new liner?

[andrij]

Hey everyone, this is the first time I'm posting here. I had some good words suggesting I post here. I'm looking to install a fireplace insert into an old pre-existing fireplace. We use it quite often and didn't clean it as often as we should have. Now to install a wood burning insert I know I need a liner, the one that the local hearth place sold me ended up not having insulation, and they said I wont need insulation in my climate. My question is about cleaning the chimney. To safely install and use a wood burning insert, does the chimney have to be chemically cleaned and essentially brand new, or is a good chimney scrubbing good enough? Thanks.

 

[begreen]

Welcome andrij. Someone is blowing smoke. What the heck does climate have to do with insulation? This is a safety measure first and foremost. The chimney needs to be thoroughly cleaned including the smoke shelf area. It shouldn't need to be chemically cleaned unless there is serious glaze creosote in the chimney. If no glaze creosote then a good top to bottom cleaning including vacuuming the smoke shelf should suffice.

 

[bholler]

Yes what he said and i will say it again get insulation they are full of crap

 

[bwells794]

What is the purpose of the insulation? Not a rhetorical question. I mean, I can use common sense and probably guess the right answer, but I've heard so many people give various reasons why you need it and then in the same breath say you might not in certain scenarios. For example, I was told that the insulation would keep the gasses in the liner from cooling and condensing on their way up the stack meaning less creosote = safer. But then, let's say you have a chimney fire: wouldn't the insulation keep the heat in the liner in the same way it keeps the cold out thus protecting from potential damage to masonry or other part of the house? If that's the case, wouldn't it make sense to insulate the liner even if the chimney was in the dead center of the middle-most room of your house? A lot of sources, including the store I bought my stove from also fed me the climate line and explained that interior chimneys don't need to be insulated (mine's on an exterior wall so that was a moot point, but you get what I'm saying...). Needless to say, I didn't buy my liner from them OR let them install it. They charged WAY too much for labor anyway.

 

[bholler]

But then, let's say you have a chimney fire: wouldn't the insulation keep the heat in the liner in the same way it keeps the cold out thus protecting from potential damage to masonry or other part of the house? If that's the case, wouldn't it make sense to insulate the liner even if the chimney was in the dead center of the middle-most room of your house?

exactly and to be to code an internal chimney needs 2" clearance to combustibles from the outside of the masonry (1" for exterior chimneys) Most do not have this so insulation is required