# Insulation around a fireplace insert



## pyroMania7103 (Nov 22, 2013)

Just got a new Osburn fireplace insert installed.

The stove sits nicely into the existing fireplace without having to do any demo, but the trim does not go far enough back to sit flush with the masonry.  What are my options to try and close this gap (roughly 1") between the trim and the masonry?  Would insulation work?  Is insulation in the fireplace a good idea anyway?


----------



## begreen (Nov 22, 2013)

I would get some 3/4" or 1" aluminum angle iron and attach it to the back lip of the surround so that it creates an extension and eliminates the visual gap. After it is drilled and dry fit, take it off and paint it black, then reinstall.

Insulation (mineral wool like Roxul) can improve heat output, especially with an exterior wall fireplace by placing it behind the stove between it and the fireplace's back wall. A damper-sealing block off plate will also significantly improve heat output with an exterior chimney.


----------



## mellow (Nov 22, 2013)

Was your fireplace not deep enough for the insert to be pushed back more?


----------



## Dave A. (Nov 22, 2013)

If you paid to have it installed that way, you got rooked (imo).  Seriously, as mellow, suggests, you should check to see if was just not pushed all the way back or if it's back as far as it will go.  Either way, a competent installer should have foreseen the problem and indicated it would fit with the gap or planned to have something fabricated to make it fit right. If that was necessary,  you should not now have to pay more for that, he should have made you aware of that before he installed it and included that in his price, unless I'm misunderstanding, and he's planning on coming back to install the piece which is still being fabricated.

But he should come back and fix it.  Ordinarily it goes without saying that a professional installer will install a full liner, in which case the fact that the surround is not pushed back is more an aesthetic issue, so no need for insulation in the gap, unless it was not installed with a full liner.


----------



## Oregon aloha (Nov 23, 2013)

Is the gap bothersome? If not just install a block-off plate and call it good. I dose not hurt to have the extra air movement around the insert. Did they push the insert all the to the back of the firebox? The stove can touch the brick and it's OK.


----------



## Iembalm4aLiving (Nov 23, 2013)

Pyro,
Congrats on your new Osburn.  You're going to love it.

My install has a similar gap.  I have cultured stone on the fascia of my fireplace, and because of the irregular surface, the surround can't be flush mounted.

At first this bothered me.  However, over time, I realized that I could only see the gap if I was right on top of the insert looking down.  

The gap doesn't affect the operation of my insert at all.  No angle iron, no insulation.


----------



## stejus (Nov 23, 2013)

The only concern I would have is if the liner is not blocked off with a block off plate, you are loosing heat up your chimney.  I would search around for block off or ROXUL and you'll learn about how to block off the gap in where the liner passes through the upper firebox into chimney.   There is no operation issue with having the gap, I have a small gap (1/2") because the insert will not go any further into firebox.


----------



## pyroMania7103 (Nov 23, 2013)

mellow said:


> Was your fireplace not deep enough for the insert to be pushed back more?


Correct.  The fireplace tapers towards the back and the firebox touches the brick.  As you can tell by the pictures on the original post, the unit fits perfectly flush at the front.  The installer said he would have had to demo the brick in the fireplace to make the trim fit flush, but recommended against it since the trim had no functional value.


----------



## Dave A. (Nov 23, 2013)

I don't understand.  If the installer told you all that and you were aware of the problem beforehand (as the installer should have been from seeing the requirements in the install manual and by measuring your fireplace) and you agreed before the install that it wouldn't go back all the way, then I can't see the point of the question about the gap.


----------



## theDokes (Oct 24, 2014)

What type of insulation should I use between the shroud and the masonry opening of the fireplace?- as shown above..
I had some in there originally but threw it away.
After 10 years it was pretty well shot.
Can I use regular R-30 or is there a specialty item which must be registered fireproof?

BTW I have the same gap space s above.
After a week you do not notice it.


----------



## begreen (Oct 24, 2014)

theDokes said:


> What type of insulation should I use between the shroud and the masonry opening of the fireplace?- as shown above..


It doesn't need to be filled with insulation, but Roxul mineral insulation is the best. Or attach a metal angle or strip to cover the gap.


----------



## theDokes (Oct 24, 2014)

The shroud comes up against the masonry and leaves spaces between the joints . 
Without insulation there is a considerable draft.


----------



## begreen (Oct 24, 2014)

Got it. Is there a sealed top cap on the chimney? Is there a block-off plate.


----------



## Lockpicker (Oct 25, 2014)

Pyromania you didnt get "Rooked". This is a very common thing. You can get some metal bent in the shape of a U and fasten it to your surround to close the gap. Where in Pa. Are you?. If your close enough I would be happy to fab it up for you. No charge you buy the material.


----------



## jeepnerd (Oct 25, 2014)

You're probably the only one that will notice it. I'd leave well enough alone. I'm on board with a block off plate though.


----------



## theDokes (Oct 25, 2014)

begreen said:


> Got it. Is there a sealed top cap on the chimney? Is there a block-off plate.



Neither!!  I just have a straight up chimney cap.
Never knew about a sealed cap or block off plate - I just now checked out some pics - Man I am dumber that I thought !!
I will shop for a block off plate as i just have a single floor ranch.
Anything special to note?
BTW, currently I have blocked off the air vents/holes in the bottom old fireplace hearth.
Should that be changed if a Block off plate is used?

Thanks !!


----------



## begreen (Oct 25, 2014)

Dokes, let's back up a bit. I would suggest starting a new thread. Your issues sound quite different. Start a new thread stating the problem and in the first post give us a good description of the setup including the insert model, a description of how it is installed and a description of the chimney setup including height and liner. For example is there a stainless liner on the stove or is it stubbed to the clay tile liner? Pictures are always welcome.


----------

