Questions about liner installation

[joefrompa]

Hi all,

Getting my Lopi Republic 1750 installed in a few weeks and I have a few questions to help guide my installation.

I have a brick chimney that's built off the side of the house (so an external chimney) on a part of the house that's single-story angled roof. The hearth is raised ~1 foot + the fireplace height + the need to go above roofline means my liner run is going to be ~16 feet.

I was told that they'll install a block-off plate on the top of the chimney where the liner exits. Is there any benefit to having a block-off plate installed at the bottom, where the wood burning stove meets the liner + chimney entrance? Is that even an option?

I'm going to get an insulated liner to help protect the longevity of the brick and help me keep a good draft. Plus it should only be like $150 extra considering the short run of the liner. Any particular types of insulation I should request or guidance there?

Should a good installer automatically re-do the mortar crown as part of the job? Mine may need it.

Is there different options for chimney caps that make it easier for future self-maintenance, or are they all pretty much the same?

Thanks all,

Joe

 

[racicotm]

I would say that a block off plate on the bottom is a good idea I feel that it gets heat into the room faster rather than waiting for the whole stack to warm up to keep the heat down. Insulating your liner is a must. As for what type of insulation i'm assuming your meaning blanket wrap or poured. I would prefer a blanket wrap insulation if your flue tiles are large enough for it. Blanket wrap i believe withstands higher temps and if you ever need to remove the liner in the future you can. As for an installer redoing your crown for free, I wouldn't count on it. (the material for doing quick crown repairs is expensive). As for caps it depends on your arrangement most liners will come with a round cap, i would prefer a larger multiflue cap aesthetically more pleasing and the tops come off easier than the round ones.

 

[tickbitty]

I have the same insert, and most everyone here thinks that you should have a block off plate at the bottom, but, I don't have one (yet). I have an interior chimney only 1 story tall, about 2/3 of the way across the house, so it's a little diffferent setup from yours. I don't feel like I am getting much heat loss up the chimney, the shroud is very effective on the back of the insert and I can put my hand on the metal damper frame a foot above it while the stove is running, so it just doesn't seem that is where the heat goes. However, may change my mind on that eventually if I am not getting what I want out of the insert. Block off plates don't seem terribly complicated to make so I can do one later. There's a wiki or something here on hearth that shows how to make one, and people have even done them in two pcs so that you can put it up around a liner that's already installed.

The block off plate at the top is a totally different thing than the bottom one, it simply covers the rest of the hole in your chimney that the liner isn't filling. The block-off plate at the bottom is required in cases where people don't have full liners (some people with masonry chimneys and tile liners may have the option of just lining up through the damper and it's open to the chimney above that) so that a chimney fire etc won't be open down into your house. But they are supposed to be a benefit regardless, for both safety and to keep the heat in the house instead of up the chimney I guess.

Seems most who have the insulated liner get it as a kit, it's blanket insulation that gets wrapped around the liner and has a mesh sleeve. You can probably get a whole kit that comes with the liner, insulation, cap and all and just tell the merchant what you are aiming for. Some insulate with vermiculite or something poured around the outside of the liner instead of the blanket kits but if you do that you definitely need a block off plate!! If you are paying for a professional installation, they may have a preferred brand/type of liner and setup they usually do, so you might need to consult with them.

I bought the liner kit mail order and had a handyman do the job to my specs, because it was easy enough for me to figure out but not quite easy enough to to myself, I didn't have the right tools and all. He didn't charge too much - compared to the cost of professional chimney installers. They presumably come with guarantees that you are to code and will meet inspections etc so that's a very good thing, but around here, they are not only super expensive, they don't like to do insulated liners and etc that they don't think are necessary, so I figured out how to get what I wanted/needed another way.

 

[begreen]

Yes there is a benefit to having the damper-seal block off plate, particularly with an exterior chimney. Without one, a lot of the insert's heat is radiated out to the surrounding masonry chimney. This can drop the heated air temps from the insert jacket down significantly. In some cases installing the damper-seal has made the difference between the stove being able to heat the house or not. This is often much less of an issue when the chimney is within the heated envelope of the house.

https://www.hearth.com/econtent/index.php/wiki/Why_damper_seal_is_needed/

 

[joefrompa]

Thanks. Looks like I'll definitely be asking for a block-off plate at the bottom in the event they aren't already planning it (they might be!)

I also really liked how one installation lined the back of the masonry with sheet metal and an insulation material. That seems like a phenomenal idea to keep the heat radiating outwards and not back through the masonry to the outside world. Is this common? Do I need to request it?

 

[webby3650]

Thanks. Looks like I'll definitely be asking for a block-off plate at the bottom in the event they aren't already planning it (they might be!)

I also really liked how one installation lined the back of the masonry with sheet metal and an insulation material. That seems like a phenomenal idea to keep the heat radiating outwards and not back through the masonry to the outside world. Is this common? Do I need to request it?

Pretty sure that technology is already built into the insert, probably won't be necessary, but you can't go wrong with a block off plate at the bottom.

 

[begreen]

Although it seems like a good idea, most of the times there is no insulation built into the insert back. It's just a metal ducted jacket for the air to blow around the hot stove envelope.