View Full Version : Crack cause and repair

Michael Thomas
07-19-2007, 02:52 PM
Masonry fireplace, looking up. (Sorry, this is the closest I could get to the center and the widest angle I could get- had to wiggle around on my back and hold the camera up through and above a partially inoperative damper - sure glad I did it, though...)

a) What likely caused this crack.?

b) What likely will be required to repair it?

Jon Randolph
07-19-2007, 05:50 PM
Heat stress maybe???????

I really don't know. Was there any exterior signs of settlement.

I don't know about the repair. I would recommend a more thorough evaluation and repair by a sweep. If you recommend an improper repair, or a proper repair that the client performs wrong, you may be liable.

Michael Thomas
07-19-2007, 06:25 PM
No evidence of settlement at the chimney exterior.

I was just curious, for myself, about how you repair a crack that extends down past the flue like that.

Jon Randolph
07-19-2007, 07:36 PM
They do make fireplace morter. It comes in a small pail or a tube (like caulk). I would recommmend replacement of the cracked tiles, all of them. A better fix may be to have a stainless liner installed with a new operable damper.

Recommend further evaluation and leave the repair to a professional.

Dale W. Feb
07-19-2007, 09:48 PM
This appears to be some form of structural failure. There is no way you can crack that flue tile so perfect and the brickwork to match. These are two different materials and will respond as such. These products will vary if this damage was caused by a chimney fire. This damage is very unusual. It appears that the chimney and fireplace structure cracked and the nonstructural liner simply followed.

A listed liner system would only address the flue liner. It would not address the structural damage within the smoke chamber or chimney. Also as a note, listed flue liners are not a structural repair, they are intended to correct the flue liner (material) damage only. If there is structural damage, the liner should not be installed. There is a serious problem with this system. I would recommend a professionally trained inspector. There is only one inspection certification in the hearth industry. This requires a F.I.R.E. Certified Fireplace & Chimney Inspector.

Removal and replacement may be necessary. A tube of caulking will not fix this one.

Michael Thomas
07-20-2007, 05:41 AM
Thanks for the quick reply.

With the limited access (grate and pile of logs, broken and partially imperative damper) this damage was not visible without moving the fireplace continents except by sticking a camera up through the damper or via something like a borescope - and even then though I took a half dozen pictures, this was the only one that provided a clear shot of the cracking.

IMO, a really, really good argument for calling for a level II at each change of ownership unless you are equipped and qualified to do one yourself.

BTW, this FP had a chimney-top damper, installed to replace (I presume) the inoperative damper below. I can't understand why the original damper was left in place with no hinge at one end and propped open by the handle mechanism. And I have to wonder (to myself that is, not in the report) if that crack was present and not detected - or even worse, ignored - by whoever installed the second damper?

If anyone cares to comment further, here are some additional pics - unfortunately I was not aware of the crack until I got back to the office and ran the the picture that shows it through Photoshop to bring out the details, so I did not investigate this in as much detail as if I had been able to observe the crack during the inspection.

One thing that puzzles me: the chimney cap does not appear to me to have been replaced when the chimney was rebuilt (?).

Sorry that I don't have a better view of the whole cap and all sides of the flues -the top was beyond my ladder...... "why take the 32 footer to inspect a ranch?" - and I had to take these from my Extend&Climb set up on the roof, which just reached to the cap... meanwhile wasps from nests at dormer eaves are trying to chase me off the roof...

Bob Harper
07-20-2007, 06:30 AM
That fireplace should be inspected as Dale said and expect some expensive repairs. That damper ajar will cause severe turbulence in the throat which can lead to spillage. Whoever installed that 13"x13" Lock Top damper was supposed to remove the old damper's valve plate first.
This chimney has undergone a major repair. Since the mortar lines don't start on one course but are staggered, my guess is there was a collapse or blunt trauma such as lightning or tree hit. The concrete crown is nice but they should have an expansion joint btw concrete and flue tile to allow for thermal expansion yet seal out water. From the cracks in the flue tile, I would venture a guess they did not have any sort of rain cap on for a few seasons, which lead to freeze-thaw damage. With that little walkway next to the chimney, I would probe the soil to find the foundation. If it does not extend out far enough, that might help explain the shearing inside the Fp. If the masonry had been extended as an elective to get more height rather than damage, you would see a clean break. It also would probably match better. This looks like insurance work.


Michael Thomas
07-20-2007, 12:48 PM
Interesting, thanks .... I learn something new from you and Dale almost every time I read your posts.

Jim Gecz
07-20-2007, 01:19 PM
When I look at the far right side of the photo - I see a cable and a shadow.

It appears to me that the "crack" is the top cap damper cable.

Yah? Nah?

Bob Harper
07-20-2007, 05:04 PM
Dang Jim your eyes are gooder than mine! I believe you are right. This is one of the problems with not being the inspector on site. On closer exam, it appears there may be the spiral wrapped sheath for the cable, which is provided by the damper mfr to shield it from rub points.

Good catch Jim! Still, I would want to know why the masonry repairs. Also, the old damper still needs to come out so still a Level II.

Dale W. Feb
07-20-2007, 08:55 PM
Jim & Bob,

I disagree. If that is the chimney top damper cable (and it does look like a cable at the far right) then it is installed into the chimney wall and behind the liner. There is no way the cable could have cut the liner and side wall of the smoke chamber. But the cable visually appears to enter into the wall. Take a close look just above what appears to be the exposed section of cable. The mortar (crack) does a slight 90-degree dog leg. This area could not be the cable or shadow of the cable. So it still remains a crack and the cause is still undetermined. This is an extremely strange one.

The extensive change to the exterior structure supports an event. I would recommend a Clue Report (an insurance claim report on the property). This will help on the disclosure end and hopeful supply an answer to your client.

Michael Thomas
07-21-2007, 07:45 AM
Came back to post a mea culpa, and found Jim had beat me to it.

I almost managed to look the Complete Idiot on this inspection, and was saved from myself only by the fact that I happened to notice at the last moment, after I had posted above but literally *just* before I hit the send button for the report, that there was another picture of that area taken before I realized had set the flash OFF - and that I had ignored up to this point as it appeared to be just a black rectangle - but which might show more of this area if I lightened it up in Photoshop.

And boy, when I did, there was some serious brow slapping, as in "OMG, OF COURSE!"

What happened? 1) I never visually observed this "defect" (I could not see past the jammed damper during the inspection, I could only hold a camera to the opening and hope I got a useful shot) so it was "identified" from a single photo 2) the next day 3) in the middle of a busy week were the various inspections and reports were already blending in my mind so 4) I had lost a lot of the mental context for evaluating what I was seeing in that picture.

The only thing that salves the wound to my pride is that a lot of other people looked, and made the same assumption..

Jim, however, nailed it.

Dale W. Feb
07-21-2007, 10:37 AM
Wow Jim,

I need you on some of my inspection. It appears you can see through walls. What a gift in this industry. Good call. What really through me of was what appeared to be a dog leg in the assumed crack. It is simply the cable running behind some parged mortar. Thank you Michael for the new photos.

This is a good photography lesson for all of us. We should review some key photos on site such as this one. If you see what appears to be something of value, change your angle and take another shot. I know this one would have been difficult as Michael was having enough difficulty in that Yoga position he was in. I wonder myself how I managed to get myself it the FIRE pose, left leg bent and under my butt, right leg fully extended next to the priceless statue, upper torso with a 35-degree twist to the left, left arm supporting the upper weight and the right arm rotated counter clockwise 15-degrees and wrapped past the damper control. Watch the eyes as the soot and leaf debris may affect your vision. Do not attempt to make a fast retreat as this will result in overextension of the right elbow, a twisted in your lower back and possible dislocation of your right knee. Maybe Bob could explain in a little more detail the medical damage. Or maybe he could just recommend a good hospital.

Back to being serious, does anyone else see the change in color of the clay flue tiles. Look at the top of the new photos and notice a brighter color. Sometime this is due to rain wash. But this is not likely on this unit because of the rain hood and usually the rain wash tapers towards the bottom (it is not a rapid change in color). This would support reconstruction or addition of the upper chimney. Jim, please look at this for use will you. I want to be sure I’m not seeing things.

Jim Gecz
07-21-2007, 12:05 PM
Here is a story about assumptions..

Had a heck of a time getting a panel cover back on yesterday. Finally my client said, "I think a breaker is in the way". Jim confidently says, "Nah!". Jim then struggles for a few more minutes.

Sure enough, a breaker was installed and one of the knockouts was never removed. I did not see it when I first took the panel cover off becuase the owner had it hanging with two screws at the top and it was loose to start, so I assumed....

I slapped my head on that one, then thanked my client.

BTW Dale - One of Michael's earlier photos shows the top portion of the chimney appears to have been rebuilt, so you are exactly right about that color change.