Blocking off other access points in my chimney?

[ikessky]

I was cleaning the chimney tonight getting ready to install the liner and found that a previous owner had made a different entry hole into my chimney. It is about a foot above the hole that I'm going to use. They filled the outer block with cement, but obviously the clay liner is gone in that spot (about a 7" diameter hole). Right now, they have some fiberglass insulation behind the cement they added, which I found because the sweep I was using pulled some of it up. Should I do anything with this hole or just leave it since I am already installing a liner?

 

[Corey]

Tough call without actually being there to see the job. My gut feeling is if the patch has restored the integrity of the chimney - that is to say the chimney is as good as it was before the hole was cut, then you should be OK. But if the patch is substandard (wondering what you mean by "some fiberglass insulation behind the cement they added" - sounds like they stuffed the hole with fiberglass and poured in some concrete? It might be something to have looked at by a local chimney sweep.

I'm sure others will chime in shortly as well.

 

[branchburner]

Is the liner going to be insulated? That would let me sleep better.

 

[ikessky]

The liner will not be insulated as I do not have enough room inside the existing clay flue. The inside of the flue is just a touch under 7"x7" and the outer diameter of the liner is almost 6-1/4" That doesn't leave me much room if there is any variation or stagger in the clay flue. Plus the chimney is an interior chimney. Although the existing clay liner appears to be in good condition, I am not the original owner of the house, so I do not know what has happened in the past. I put the camera inside the flue from the bottom and snapped some pictures and everything looks real good except for the area where the T will pass through.

And yes, whoever did this did a very bush league job. They stuffed the hole with fiberglass insulation and then patched the outer concrete block. It is maybe three inches thick of concrete and the block is at least 4 inches thick. I'm thinking I should undo this patch, use a screen and refractory cement from the inside to cover the hole in the clay flue, and then fill the entire hole in the cement block with cement/concrete.

As I said, the area in question is only a foot or so above where my T for the liner will come through the chimney. I'm thinking this is a moot point because the area is inside, away from combustables, and the chimney is being lined anyway.

 

[Jack33]

Was this being used in it's current state without a liner? If so, I wouldn't be overly concerned since you are lining it. But...I might fix it since I am a perfectionist. Could you knock out the plug and use the upper hole rather than the lower? Plug or just insulate and cap the bottom and your concerns are solved.

 

[ikessky]

No, using the top hole puts my stove pipe a little too close to a floor joist. Distance wise, I would probably just squeek by the minimum, but I am nervous by nature. The location of creasote that I cleaned out would indicate to me that someone was using it in it's current state.

I really think that I've overthinking this whole thing because I am already installing a liner. I got the thicker .007" liner also. I think I will repair the area like I outlined above anyway. It won't take long and then I won't have to think about it again. I may redo the entire chimney in the next few years anyway when I reroof the house and remodel the bathroom.

 

[ikessky]

I came up with a new plan. I found some old pieces of clay tile that I will roughly cut to the size of the hole. I'll cement it in as close as I can to the flue tile with refractory cement and then fill the hole in the block with more cement. I know, I know. I'm already putting a liner in, so why do this? I get real off on certain things!