Interior chimney block off plate

[Asapappa]

I just got a quadra fire voyager grand installed yesterday. It was installed in an existing masonry fireplace that has the brick chimney on an exterior wall but it's not exposed to the outside. The installer said I didn't need an insulated liner, just a regular 6" stainless steel one, and that I didn't need a block off plate or any insulation installed. Before I go to use this thing, should I insulate and install a plate, or see how it does as is first? The chimney is much bigger than the liner (I would say at least 18"x8" with no clay flue). The exterior cap is just a stainless plate with a pre fab cap that he installed with construction adhesive and silicon caulk. The house is an 1887 farmhouse with some insulation, but could use more, and the room it is in is a recently expanded family room (20x32') with a fairly open kitchen attached to that. The insert will primarily be used to supplement the natural gas well that we own, so that we don't run out of gas mid January like we have been for the past several years. Thanks for the input!

 

[bholler]

I just got a quadra fire voyager grand installed yesterday. It was installed in an existing masonry fireplace that has the brick chimney on an exterior wall but it's not exposed to the outside. The installer said I didn't need an insulated liner, just a regular 6" stainless steel one, and that I didn't need a block off plate or any insulation installed. Before I go to use this thing, should I insulate and install a plate, or see how it does as is first? The chimney is much bigger than the liner (I would say at least 18"x8" with no clay flue). The exterior cap is just a stainless plate with a pre fab cap that he installed with construction adhesive and silicon caulk. The house is an 1887 farmhouse with some insulation, but could use more, and the room it is in is a recently expanded family room (20x32') with a fairly open kitchen attached to that. The insert will primarily be used to supplement the natural gas well that we own, so that we don't run out of gas mid January like we have been for the past several years. Thanks for the input!

your installer was full of it that you did not need insulation. This is a prime example of chimney that really really needs an insulated liner. Old soft brick with less than perfect mortar no clearance to combustibles and probably pyrolized wood touching the chimney. And yes a block off plate will be of great help keeping the heat in the house where you want it.

 

[jatoxico]

IMO insulating the smoke shelf and installing a block off plate is always an advantage. What your installer is probably saying is that the interior brick will heat up and slowly give that heat back to the house but I'd rather send max heat to the room. The brick will heat up anyway. Mostly installers just don't want to do it. And, insulating as much as possible is also good to keep flue gases as hot as possible to minimize creosote formation.

 

[Asapappa]

That's what I was afraid of. He said that these inserts are so efficient that a big heavy insulated liner wasn't worth having. They has it pulled in from the inside out in about 60 seconds.

 

[begreen]

Insulation doesn't add that much weight. With that large a chimney pulling an insulated liner would have been easy.

 

[Ashful]

Fellow old house nut here, although mine is about 150 years older than yours. Bholler will correct me on the terminology (he's a certified sweep), but what's usually recommended for an old house without liner is a category-2 inspection, to verify the chimney structure is solid, and there is no combustible materials (eg. Wood) inside the chimney.

Assuming it's solid and free of combustibles, but lacking any sort of liner, the usual prescription is an insulated liner. The issue with an un-insulated liner in an unlined chimney is the exterior clearance to the cumbustibles, which is often zero.

In my case, I had the opposite, folks trying to sell me all sorts of things I didn't need (much of which didn't meet code, if I actually had the issues some tried to claim). Double-check all quotes.


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[Asapappa]

So, should I be worried about this installation and my insurance company if anything should happen? I am pretty mechanically inclined, but I worry about taking this thing apart, because they attached the liner to the insert, installed the cast surround, and then put the plate on top of the chimney, pulled the liner extremely tight and then attached the chimney cap. I'm afraid that if I just remove the liner at the insert inside the house, that it will be almost impossible to re attach without unfastening everything on the roof due to how tight it was pulled. What a nightmare. I should have just done this all myself on the first place.

 

[bholler]

So, should I be worried about this installation and my insurance company if anything should happen?

Well no it is not code compliant but the liability would fall on the installer not you. So from the insurance standpoint you are safe. But from an over all safety standpoint you may not be safe.

What a nightmare. I should have just done this all myself on the first place.

No your installer should not have been a hack that is not your fault. If it was me I would find somewhere that you have wood touching the chimney structure I am sure you could find that in the attic. Take a picture of it then print out this. (broken link removed to http://codes.iccsafe.org/app/book/content/2015-I-Codes/2015%20IRC%20HTML/Chapter%2010.html) And show him R1003.18. Tell him his install does not meet code and he has put your safety and the safety of your family at risk and he needs to fix it now or you will report him to the local building authority bbb ect.

 

[Ashful]

The fix is pretty simple, BTW. They just wrap an insulation blanket around the liner, fasten it on with foil tape, and then wrap wire (or a giant wire mesh sock) over that. However, it does need to be removed from the chimney to do this, so it's best to have the original installer do it.

Given the size of your chimney (if the small dimension is really 8 inches), a blanket-wrapped 6 inch liner will just fit. It will be tight, but it will fit. I have a blanket-wrapped 6" liner installed in a round 8" clay tile flue, on one of my stoves.

 

[Ashful]

I just realized we didn't answer the block-off plate question. They are not required for code or safety, but they do make an enormous difference in how much heat stays in the room vs. going up the chimney. It's normal for installers to not bother with them, most here have installed their own. Mine are sheet metal sitting on perf angle channel, Tapcon'd into the masonry. Others use Roxul, I believe.

 

[begreen]

A block off plate is required with a direct connect installation. Fortunately though we see few of them here.

 

[Asapappa]

What is a direct connect installation?

 

[begreen]

This is where the liner is stubbed about a foot up into the chimney. I don't recommend this type of installation because the chimney area is often too large which can cause the flue gases to slow down and cool too much. It also requires removing the insert to do a good cleaning.

 

[Asapappa]

But if my liner extends all the way to the roof, it's not a direct connect install, right?

 

[begreen]

That's right, you have a full liner.

 

[Ashful]

A block off plate is required with a direct connect installation.

Yes, this is always good to point out, for others. But we already knew the OP was installing a liner.