Chimney\Liner Question - with MS Paint Awesomeness!

[Clarkbug]

Hello All.

Im posting this here, since I figure more people on this forum tend to think chimney/liner than over in the boiler forum, but I could be wrong.

I started a thread over there, but the long and the short of it is that prior to a boiler install I got my chimneys inspected, and the sweep said both need liners. Not cool. And more relevant, not cheap.

I have a mason coming out to take a look at them (not sure I trust the sweep for a host of reasons), and hopefully he can give them a structural clean bill of health. I want to try and put a liner in my smaller chimney, which is about 22' tall and currently has an 8" round terra cotta liner in it.
(please now refer to the amazing and highly technical sketch)

This sketch is a cross section of what I have now. There is a "thimble" that comes through the exterior wall, and below that there is a cleanout door. Thimble is in quotes because its actually just another piece of terracotta liner, with no actual mortar around it, and I can see daylight through it. Not good.

I would like to put a 6" liner in this chimney, and then pour some of the vermiculite cement around it. My actual question involves the bottom part of the chimney. The cleanout door is shot, and needs replacement. What I am wondering is if I can fill the part of the chimney I have shown with the pink "/" with sand or pearlite or something, and then just fill in where the cleanout door is with brick. Then any cleaning of the chimney would be done through the thimble, since there will be the T that attaches to the bottom of the liner anyway. Is there a reason why this would be a bad idea? Any comments/questions/thoughts are most welcome!

 

[pen]

I have a similar setup and it is only So/So. In my case because of the size of my liner I coudn't get a solid T down the chimney so I instead pulled the liner down and inserted a 90 at the bottom going into the thimble.

The advantage of a T is that is gives some room for flake creosote to fall into w/out restricting the turn. If I could have gotten a T down my chimney I would have to only clean once per year. The T simply would have a cap on the bottom that I would never remove. However I clean 2x per year just to make sure that there isn't build up in that 90.

I could place a T externally to serve as a long clean out but aesthetically it would look like dog poo.

How far away is the current cleanout door up to that thimble? If they are close enough you could literally reach your arm up the old clean out and remove a cap on the bottom of a T for cleaning.

pen

 

[Clarkbug]

Thanks for the quick reply Pen.

The cleanout door is about two feet below the thimble. I dont think I have a long enough arm to get in there and remove the cap on the bottom of the T. But I should be able to fit the T in there OK, since its an 8" tile, and I can go with a 6" liner. My thought is to use the vermiculite cement, so I would need to do something to keep it from filling in below the T anyway.

The other issue is that the cleanout door is really just a hole in the cinderblock foundation that goes into the chimney, and there a part of the terra cotta liner is broken out. So I cant even decide to install a T in the liner, then put another short piece of flex and then a 90 out to the cleanout door, at least not without breaking some tile out of the way.

 

[Todd]

If there is any way to salvage that clean out I would do it. Sure makes it easy to sweep. Have you ever looked into a poured chimney liner like Supaflue? Little more spendy but they have a lifetime warranty, fill in all the cracks and are well insulated. I had one poured this Spring and she drafts like a Hoover.

 

[jimbom]

Two thoughts:

Keep the clean out and drop a straight piece of pipe on the bottom of the tee so that you could take off the cap for cleaning.

Consider perlite since it absorbs less water.

I switched my encore to rear vent so I could put a tee in for monitoring of the flue. All we have to do is drop the cap on the bottom of the tee and use a mirror to look up the chimney. Our Atlanta stove only vents from the top, so checking it is more of a hassle.

 

[Clarkbug]

Hmmm, thanks for the input guys.

I guess my next question is why does the cleanout make it easier to sweep? Forgive my ignorance here, but I just dont know why pulling any creosote out of the T at the thimble is easier than through the cleanout door.

Also, if Im going to keep the cleanout, would would be the best way to keep the Thermix (or equivalent) insulation from filling the entire cleanout cavity?

Is there an advantage to something like the Supaflu over a stainless liner?

 

[jimbom]

... the best way to keep the Thermix (or equivalent) insulation from filling the entire cleanout cavity? ...

You could use a metal plate to block off the masonry openning below the thimble. The hole in the plate for the down pipe could be made tight enough to keep the insulation from filling the lower cavity.

 

[Todd]

The great thing about a cleanout is you don't have to disconnect the stove pipe to get at the creosote after sweeping your chimney. I check my stove pipe about every other year and it's always pretty clean, most of the soot is in the upper chimney.

I think the main advantage of a Supaflue over a s/s liner is how it reinforces the whole structure and makes the chimney stronger.

 

[begreen]

Thanks for the quick reply Pen.

The cleanout door is about two feet below the thimble. I dont think I have a long enough arm to get in there and remove the cap on the bottom of the T. But I should be able to fit the T in there OK, since its an 8" tile, and I can go with a 6" liner. My thought is to use the vermiculite cement, so I would need to do something to keep it from filling in below the T anyway.

The other issue is that the cleanout door is really just a hole in the cinderblock foundation that goes into the chimney, and there a part of the terra cotta liner is broken out. So I cant even decide to install a T in the liner, then put another short piece of flex and then a 90 out to the cleanout door, at least not without breaking some tile out of the way.

Could the tee have a short extension on it so that reaching the cap is easy or so that it connects to a second, cleanout tee at the cleanout door?

 

[Clarkbug]

Thanks All.

I guess I could install a second tee for cleanout purposes, Ill just need to try and bust out some of the terra cotta to get a snout on it. I may end up having to use a 90 instead, since I might not have the room for the protruding portion of the T.

Time to do a little more measuring and figure out the next best step.

On a related note, whats the best way to install a new cleanout door? Just get some mortar and stick the sucker in there? The one I have now is definitely shot, so I either need to replace it or fill in the hole.... (Plus I need to go find a replacement door!)

 

[begreen]

The snout goes on after installation of the liner. There are no protrusions when dropping down the pipe. Take a look at the installation instructions for the liner.

(broken link removed)

 

[Clarkbug]

Sorry, I meant the bottom of the T, not the snout of the T.

 

[begreen]

My understanding is that you cap the bottom of the cleanout tee before lowering the pipe down the flue.

 

[Clarkbug]

An update!

I had a mason come out to look at the physical condition of my chimney this afternoon, since some of the blocks looked a little rough to me. He agreed that there are several bricks that are deteriorated, and that my thimble is essentially non existent. The good news in all of this is that he couldnt understand why I would need a liner if it was not required for my boiler installation (its not). The tiles are not perfectly lined up, but he mentioned that round tiles tend to shift some, usually more than square ones. Im awaiting his estimate, but the idea would be to replace some of the upper blocks, fix the flashing and replace the thimble and cleanout door properly.

So its looking like I may be able to spend my money on the other chimney that I know needs a liner, and maybe just get this one fixed the right way. I get the feeling the sweep I had out was just looking for a quick buck. (he charged me 199 for EACH chimney, plus tax! I would get he needs to charge that for one chimney to cover travel, but you think I would get a break once he is already on site!)