Advice on Liner Termination

[riles246]

I'm in the process of getting an insert for my masonry fireplace. I have a TN20 on order, and in the meantime got a couple of quotes from chimney sweeps to install the liner (I don't love going on roofs otherwise I'd do it myself).

The chimney is total about 23' high, and roughly 18' of that goes through the middle of my conditioned space (two floors); the last few feet run through the unconditioned attic and through the brick on the outside. I have a cap on the top of the existing chimney that I like the look of; I've attached a picture that I took using a drone the other day.

Two questions- 1. insulated vs. uninsulated. Both companies said "uninsulated is fine in this chimney". Curious to hear the thoughts from people on this board.

2. The trickier question. One of the companies wants to install the liner by cutting a hole in the existing cap and attaching the cap that comes with the liner on to the top of the existing one. He said the current cap isn't tall enough to terminate inside the "cage" and that it's far cleaner just to attach it to the top. The second company said that I could, in fact, retain the same cap and that they could terminate inside the "cage" (sorry, I don't know the real term). Both are priced similarly and I think I'd like the look better if it terminated inside the existing cap. Thoughts?

Neither company went up on the roof during the quote, but the second one, the one who thinks they can do it inside the cap, looked at my drone photos before giving his opinion.

 

[EbS-P]

Just do an insulated liner. Chances are you do need it unless you can 100% confirm you have 2” from ALL combustible materials and the chimney, this includes roof decking. Second thought do you meet the 10-2 rule? Termination must be to feet higher than anything within 10 feet.

Last, you need at least 4”, code might say 6” sticking out above the top cap that sits on the chimney. I was able to keep my SS chimney cap in place and terminate liners inside the cage.

 

[riles246]

Just do an insulated liner. Chances are you do need it unless you can 100% confirm you have 2” from ALL combustible materials and the chimney, this includes roof decking. Second thought do you meet the 10-2 rule? Termination must be to feet higher than anything within 10 feet.

Last, you need at least 4”, code might say 6” sticking out above the top cap that sits on the chimney. I was able to keep my SS chimney cap in place and terminate liners inside the cage.

View attachment 314347

About the 10-2 rule, you know it's funny, that crossed my mind right as I was making this post. This house was flipped before I bought it and the flipper changed the roofline. Basically none of the construction was done well/correctly, and the town appears to have rubberstamped everything without checking. There is no way that chimney is high enough. This house used to be a single story cape that had a second story added in three phases with the roofline changing each time, my purchase being the final phase.

Interestingly, during the home inspection, the home inspector identified that the furnace exhaust was in a deadly spot (it really was- under the soffit pointing down, with gases coming right back into the house), so the builder begrudgingly hired a new HVAC installer to put in a proper furnace flue. The HVAC company got it right, see this pic. But that wood chimney hasn't been extended since the house used to be a single story.

Funny that neither of the pros who came out to quote the insert and liner noticed though.

 

[gthomas785]

Oh man, you're going to want to raise the height of that chimney substantially. If you get any more than ~6" of snow it'll be buried. Also check how the roof was done around it. I can see step flashing but it looks like it's just kind of slapped onto the side of the chimney and not tucked into the mortar joints. If it doesn't leak now, it will in the next 5-10 years.

 

[riles246]

Oh man, you're going to want to raise the height of that chimney substantially. If you get any more than ~6" of snow it'll be buried. Also check how the roof was done around it. I can see step flashing but it looks like it's just kind of slapped onto the side of the chimney and not tucked into the mortar joints. If it doesn't leak now, it will in the next 5-10 years.

Thanks. To your point, here is another pic showing the flashing. Nothing done on this house is done well/right (you should see what they did with the plumbing...). But it's not all bad- it was probably $100k less than it would have been if it had been built well, so I'm still net ahead even as I fix stuff.

What would it be like to raise this chimney- do I have to have someone add bricks or can be it be done with chimney pipe?

 

[Ctwoodtick]

Insulated liner? Yes
Raise height of chimney - yes
Once these issue are fixed, I would use a chimney cap that fits the situation. That seems pretty hack for that person to suggest going through the existing cap.

 

[gthomas785]

What would it be like to raise this chimney- do I have to have someone add bricks or can be it be done with chimney pipe?

You could certainly use the liner termination flashing on that existing chimney height and then extend off of that with class A chimney pipe. Keep in mind the pipe needs bracing if more than 5 feet.
People do this all the time, usually when they have an existing liner with poor performance and they're after more height. Personally I think it's pretty ugly... is this on the front of your house or in a place where you can see it easily?

If it were my house I would get a chimney mason to build the chimney up 3-4 feet above the ridge, terminate the liner flush with the brick and then put the original cap back on it or a similar one if the existing one is less than 6" tall. Since it's painted you don't have to worry about matching brick colors and that nonsense. But they would still have to bring staging and yada yada so probably a 2 day job and a couple thousand $$ to do it.

 

[riles246]

You could certainly use the liner termination flashing on that existing chimney height and then extend off of that with class A chimney pipe. Keep in mind the pipe needs bracing if more than 5 feet.
People do this all the time, usually when they have an existing liner with poor performance and they're after more height. Personally I think it's pretty ugly... is this on the front of your house or in a place where you can see it easily?

If it were my house I would get a chimney mason to build the chimney up 3-4 feet above the ridge, terminate the liner flush with the brick and then put the original cap back on it or a similar one if the existing one is less than 6" tall. Since it's painted you don't have to worry about matching brick colors and that nonsense. But they would still have to bring staging and yada yada so probably a 2 day job and a couple thousand $$ to do it.

Thanks that's what my mind has been leaning towards as well, just in the few hours that I've been processing all of this. It's very prominent on the front of my house so Class A would look pretty bad. Plus I love the point about the paint- not hard to match.

Key question would be cost. I live in a high cost of living area so even the quotes just to install a plain jane uninsulated liner have been sky high, so I'm terrified of what a few feet of brick on the chimney will run me. So we'll see.