First time homebuyer: questions from chimney sweep's report

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buttonsbear1

New Member
Sep 13, 2021
5
Pennsylvania
Hi, all-
I'm trying to better understand the notes from an inspection of my 1970s stone fireplace. The inspection notes two underlying issues in need of patching:
  1. a lintel gap
  2. an old "flue base" (for a flue damper which has since been removed and replaced with a top flue damper)
I've attached a picture looking up from the fire box, with the picture oriented so that room that I'm standing in/interior wall is towards the bottom. My general understanding (sorry, I'm new to this) is that it's undesirable (to put it mildly) to have any smoke escaping towards the front interior wall rather than up towards the chimney, and that thus the sweep was noting that fireplace mortar needs to plug the two gaps I've identified in the picture. Is this a reasonable interpretation? (Boy am I wishing I'd stuck my head up in the chimney while he was here to ask these questions.)

fireplace question 1.JPG.png

One other question, now that I'm looking around in there:
I'm surprised to see fuzzy insolation (or something similar) around the two small front walls of the fire box shown in the picture below. Can anyone identify it and let me know whether it's safe for it to be uncovered like this? It looks to the uninformed eye like something that would be potentially flammable given the texture.

fireplace question 2.png
Thanks for any education you can give me!
 

armanidog

Feeling the Heat
Jan 8, 2017
273
Northeast Georgia
Are you planning to use the fireplace?
That insulation looks like rock wool which is not flammable.
(Non-combustible, fire-resistant up to 2150 degrees Fahrenheit)
And it seems your interpretation is correct about the gaps.
 

buttonsbear1

New Member
Sep 13, 2021
5
Pennsylvania
Are you planning to use the fireplace?
That insulation looks like rock wool which is not flammable.
(Non-combustible, fire-resistant up to 2150 degrees Fahrenheit)
And it seems your interpretation is correct about the gaps.
Thanks, armanidog, that's helpful. Yes, we're planning to use the fireplace, after the gaps are filled in. Eventually we hope to add an insert and gain a more useful heat source, but for the immediate winter our more modest goal is to get it back in safe working order as is.

We're trying to decide whether to try to patch it ourselves and get it reinspected or have the repair done by a sweep. I'm leaning towards trying to patch it ourselves, as a nonstructural problem that can be done from the ground like this seems like a good learning project.

Does anyone have recommendations on what type of mortar to use to fill in the gaps? They seem too big for the easy diy fireplace mortar caulk . Will this work or is there something more appropriate? Part of the patch will need to be mortar to metal since we're patching against the old flue damper, although I haven't been able to find a product specifically marked for patching between the two.
 

bholler

Chimney sweep
Staff member
Jan 14, 2014
25,576
central pa
Thanks, armanidog, that's helpful. Yes, we're planning to use the fireplace, after the gaps are filled in. Eventually we hope to add an insert and gain a more useful heat source, but for the immediate winter our more modest goal is to get it back in safe working order as is.

We're trying to decide whether to try to patch it ourselves and get it reinspected or have the repair done by a sweep. I'm leaning towards trying to patch it ourselves, as a nonstructural problem that can be done from the ground like this seems like a good learning project.

Does anyone have recommendations on what type of mortar to use to fill in the gaps? They seem too big for the easy diy fireplace mortar caulk . Will this work or is there something more appropriate? Part of the patch will need to be mortar to metal since we're patching against the old flue damper, although I haven't been able to find a product specifically marked for patching between the two.
If the rest of the fireplace is constructed correctly those gaps are no issue at all. But I would probably fill them. I would use a product like chamber tech for that application. But honestly if I was doing the job I would recommend cutting that damper frame out and smoothing out the throat area including tapering the smoke shelf up.
 

buttonsbear1

New Member
Sep 13, 2021
5
Pennsylvania
If the rest of the fireplace is constructed correctly those gaps are no issue at all. But I would probably fill them. I would use a product like chamber tech for that application. But honestly if I was doing the job I would recommend cutting that damper frame out and smoothing out the throat area including tapering the smoke shelf up.
Thanks, bholler. That's helpful. I don't know if we'll go so far as to cut the frame out before this fire season, but I'll keep that in mind for when our other new house projects are more stable, and the product recommendation is useful.
 

armanidog

Feeling the Heat
Jan 8, 2017
273
Northeast Georgia
Did the inspection include checking the upper flu for creosote and any damaged clay flu liner? How about the crown of the chimney?
If not I would have someone like a chimney sweep use a camera to inspect the flu and also check the crown of the chimney.
 

buttonsbear1

New Member
Sep 13, 2021
5
Pennsylvania
Did the inspection include checking the upper flu for creosote and any damaged clay flu liner? How about the crown of the chimney?
If not I would have someone like a chimney sweep use a camera to inspect the flu and also check the crown of the chimney.
Yes, we paid for a thorough inspection already. (Thanks for checking!) Per the sweeps report, the fireplace appears to have almost never been used, and thus almost no creasote build up. The fireplace cap will need an eventual update, but there's nothing pressing, just not the prefered metal cover that would likely have been put up there if it were built today.
The two patches are the only immediate safety concerns the sweep noted, so we'll get them fixed up and rechecked before the first fire. Safety concerns aside, I'm reluctant to put too much more effort into it until we decide we make it through a winter and better understand how often we'll be tempted to use it. Long term assuming we use it as often as I expect, we'll almost certainly install an insert, but that's more work than we can handle this year.
 
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bholler

Chimney sweep
Staff member
Jan 14, 2014
25,576
central pa
Yes, we paid for a thorough inspection already. (Thanks for checking!) Per the sweeps report, the fireplace appears to have almost never been used, and thus almost no creasote build up. The fireplace cap will need an eventual update, but there's nothing pressing, just not the prefered metal cover that would likely have been put up there if it were built today.
The two patches are the only immediate safety concerns the sweep noted, so we'll get them fixed up and rechecked before the first fire. Safety concerns aside, I'm reluctant to put too much more effort into it until we decide we make it through a winter and better understand how often we'll be tempted to use it. Long term assuming we use it as often as I expect, we'll almost certainly install an insert, but that's more work than we can handle this year.
A metal cover on a masonry chimney is not at all the standard. Or even preferred. They work fine I just don't like the look and they do have some drawbacks compared to a poured crown