Back Plate yes or no, need your advice

[Squeaky_6]

Hey Guys,

So I have a Country Comfort 300, FINALLY installing it this weekend...
Everyone on here thinks it needs and 8inch Liner, I only have 6inch and want to install that liner so when I get a different stove, chances are it will be 6inch and a simple install.

My Question: If I don't install a back plate at flue, would this help heat go up chimney and keep my gas temps hotter up high for a better draft, or am I way off base?

My thinking is install using 6inch liner, no back plate and the extra heat will help with draw, then when I buy a new stove, I can install back plate later.

The chimney is on back side of exterior wall that is connected to the garge, so it isn't complete exterior brick. I notice the draft up is way better because it seems warmer than at my house, where the chimney is completely exterior and gets cold. This stove will go in at my girlfriends house.

Any thoughts?

Thanks All!

 

[Squeaky_6]

Also, I burned the stove in driveway to cure the paint and had a 6inch liner on it, seemed to work well, some smoke when I opened door to fast and I am hoping because it was outside on a windy day which did not help.

 

[begreen]

By back-plate it sounds like you are referring to a key or stove pipe damper. If so, I would try running the stove without it. Be sure there are proper and adequate clearances for the stove and the stovepipe.

 

[Squeaky_6]

Sorry Begreen, I am not sure I had the correct name. I am talking about a piece of metal above the stove, covering the chimney opening and cut out around the liner, to keep heat from escaping up the chimney, with roxul on top of the metal to insulate. I have read other threads about these on the site but can't remember the correct name.

I was thinking if I didnt have this, heat would go up chimney but help keep the flue gases hotter for better draft.

What you think worth it or not?

 

[begreen]

Ah, you mean a block-off plate. For sure do that. It will make a notable improvement in retaining stove heat in the house. Insulating the liner is the way to keep the flue gases hotter.

 

[bholler]

Is the liner insulated if so there is no reason to want extra heat up there if not it should be

 

[Squeaky_6]

Liner is not insulated right now, I haven't installed it yet. I was kinda hoping to not insulate it since it is basically an interior chimney... I understand that is not code, but it seems to be a back and forth topic on the site so was going to try it without and could always install one if need for the draw out the liner.

 

[bholler]

On an interior chimney it is as much about safety and making sure your house doesn't burn down as it is about performance. There is a reason code requires it just do it right the first time

 

[Squeaky_6]

Agreed... How does insulation prevent a fire? It seems weird to me the insulation prevents fire in a non combustible masonry chimney and flue.

In the old days they let stoves just go up your existing chimney and flue with no liner right? That doesn't even seem dangerous, since everything is non combustible and a fire place works without a liner.

Do stoves produce much more heat so they require the liner and insulation?

 

[begreen]

Can we get a clarification on the code? My understanding is that single-wall liner is ok if the interior chimney has 2" clearance from wood. Is that correct?

 

[bholler]

Can we get a clarification on the code? My understanding is that single-wall liner is ok if the interior chimney has 2" clearance from wood. Is that correct?

Yes it is sorry bg i should have added that but the chances of having that are very slim but you are right

 

[begreen]

FWIW, our old furnace flue was built that way. I know because I removed it. The fireplace chimney however had direct contact with wood from remodels. That is history also.

 

[bholler]

Agreed... How does insulation prevent a fire? It seems weird to me the insulation prevents fire in a non combustible masonry chimney and flue.
In the old days they let stoves just go up your existing chimney and flue with no liner right? That doesn't even seem dangerous, since everything is non combustible and a fire place works without a liner.
Do stoves produce much more heat so they require the liner and insulation?

They found that without the required clearance from the outside of the masonry which is 1" for exterior and 2" for interior that there can be enough heat transfered through the masonry to set the combustibles on fire. So without those clearances a clay lined chimney is not to code and when you put a liner in you need to insulate it

 

[bholler]

FWIW, our old furnace flue was built that way. I know because I removed it.

I have seen a few that were done right but the vast majority are not

 

[Squeaky_6]

Bholler, thanks for info, I guess it just boggles my mind that you have a fireplace and it's ok, but with a stove it changes things. Thanks for all the replies!

 

[bholler]

Bholler, thanks for info, I guess it just boggles my mind that you have a fireplace and it's ok, but with a stove it changes things. Thanks for all the replies!

Really with out those clearances it was not ok as an open fp either but no one was checking it but when you change it you need to bring it up to code. And besides the increase in performance will be enough to make it worth the extra money

 

[Squeaky_6]

Update Guys:
I measured and a 6inch liner plus insulation will not fit! I bought the insulation and plan to insulate my liner. Now looking at the idea of breaking up the clay flue tiles to make room...To say the least the girlfriend is not happy since "The fireplace worked just fine!" I am trying to sell her on the benefits of an actual stove, especially since I cut, stack and split all the wood, but I am losing hope here guys!

Anyone ever have a clay liner broke out and remember what it cost? I got a absolute low end estimate of 1200 just for break out, that seems super spendy to me.

Anyone ever break out their old liner and have a positive or horror story to share?

Thanks again all!

 

[Squeaky_6]

also, anyone have to cut part of a metal damper out to make room for their liner? That looks like something I will have to do also. Maybe just try an oval liner? Would still be cheaper than a break out of my clay tiles..

 

[begreen]

What is the chimney tile inside dimension?

Yes, many have cut a notch in the damper to clear the liner.

 

[Squeaky_6]

6.5x11 approximate

 

[BrotherBart]

Go up in the attic and see if the dang chimney is closer than 2" to combustibles. If it isn't, put the single wall liner in the thing. Wreck her chimney and you are not gonna have a happy GF. Or a GF at all.

 

[bholler]

Go up in the attic and see if the dang chimney is closer than 2" to combustibles. If it isn't, put the single wall liner in the thing. Wreck her chimney and you are not gonna have a happy GF. Or a GF at all.

It is not just the attic it is the entire length of the chimney you need to worry about but the attic is a good place to start. How many chimneys have you seen wit hthe proper clearance bart? And why are you always so against breaking out liners There are allot of times it is the right thing to do. There are also many times that it is not necessary or feasible. Another option would be to ovalize the liner. But i have said it many times and discussed it wit hthe op in private messages but i dont feel break out is a diy job there are allot of things that can go wrong if you dont know what you are doing.

 

[Squeaky_6]

Chimney is on exterior wall but in an attached garage. I will try to get some pics posted. I will check in attic also and just see what is going on. House was built in 1969, if that helps for what code was back then.

I like the idea of busting out liner and installing my insulated stainless steel rather than buying all new liner and parts.

Appreciate the help!

 

[bholler]

No need to buy all new just find some one with an ovalizer

 

[BrotherBart]

And why are you always so against breaking out liners

Serious consideration needs to be given before you go having somebody spend $1,200 knocking the tiles out of the chimney of a fireplace they like just fine as is and you don't own the house. As well as the impact if they later want to sell the house with a now non-workable fireplace.