New here but need advise on install

[drocker]

I have been lurking around here for about 3 years now. I have learned a lot from the post I have read. It's taken a while for me to find the stove insert I wanted and to recondition it. I bought an older Ashley AHI1B stove insert. The current fireplace appears to be one of those steel fireboxes that the chimney and brick mantel is built around. The damper is 5 inches by 26 roughly and the flue going up is 15.5" X 11.5". So quite large and in my mind to large for the fireplace. We never really used it as it just seems like most the heat went up and out anyways. I know the chimney will need to be cleaned then lined with a 8" liner. I plan to cut a round hole through the damper and part of the metal around the damper for the liner to come through. It is an external chimney so I am going to insulate the whole flue with Perlite. So I have 2 questions.

1. Do I need a block off plate if most of my damper is still there and there is a good seal around the liner? The damper will be about 16 inches from the stove insert top.

2. This may sound like a dumb question, but currently there is a flip door in the bottom of the fireplace you can open to let the ashes drop down to an cavity that you can then clean out from the outside. So my question is when I scrape the flue, will the creosote fall down behind and past the damper then down to this clean out area. Or should there be a shelf back there? Reason I ask is if there is no shelf, I am going to have fill up that whole void and where the ashes fall with perlite as it will fall down there anyways.

Thanks,
Dennis

 

[coaly]

A liner should be connected to stove top with what is called a boot. If one is not available for the rectangular size you need, one would need to be fabricated usually from stainless steel. Cleaning flue then falls down into stove instead of behind it when no liner was used. This prevents the necessity of pulling Insert to clean behind it each time.

Similar to this;

 

[drocker]

Thanks Coaly. The adapter I need is on order, but I am asking about creasote falling behind the fire box prior to installation of the liner or insert. If there is no shelf back there, when I clean the flue, the creasote will fall down on the back side of the firebox that is already there. That also means when I go to pour the perlite down from the top, it too will end up fallind down the back side. That means a lot more bags of perlite to fill in all that extra area if it falls behind and below my current steel firebox.

 

[coaly]

Ah, I thought you meant where would it go when you cleaned the flue after liner installation....... Extend the existing flue liner down into the steel firebox with a rectangular metal box to act as sides all the way down to prevent filling cavity with perlite?

 

[bholler]

First you dont want to fill the chimney with straight perlite if you want to use pour in you need to use the premade mix of either vermiculite or perlite and cement. But honestly with a flue that big i would not fill it i would use wrap you are going to be pouring a long time to fill that. Not hing wrong with it if you use the right stuff it will just be a real pain

 

[begreen]

+1 for using insulation wrap. It will be a neater, faster install and if anything ever goes wrong with the liner it will be easier to pull and install a new one.

 

[drocker]

The reason with going with just straight perlite is that I can get about 15 cubic feet of it for about 50 dollars through where I work. Insulation kit for the size I need is another 300 dollars added to the cost of installation.

 

[BrotherBart]

Lots of liners in Europe are insulated with Perlite or Vermiculite loose fill. The pita is that if the block off plate on the bottom leaks or you ever have to pull it you end up with a living room full of the loose fill.

 

[bholler]

Lots of liners in Europe are insulated with Perlite or Vermiculite loose fill. The pita is that if the block off plate on the bottom leaks or you ever have to pull it you end up with a living room full of the loose fill.

It used to be done here all the time to there are a couple problems the one you have stated already and the fact that both materials will compress and settle over time from the expansion and contraction of the liner. Neither are approved chimney insulation here anymore