Questionable chimney crown sealant?

[Robb]

A previous owner had applied a black coating to the chimney crown that looks like roofing tar (see pic). The chimney has had some leakage problems in the past but after caulking some mortar lines and applying water proofing to the stone it is much better. I also applied flashing sealant to the black coating on the crown where it was cracked. Directly underneath the cracked areas the surface mortar was noticeably crumbly. After thinking about it I questioned whether roofing tar (if that is what it is) is safe so close to the flue outlet? I don't use the fireplace that much but was thinking about installing an insert and flue liner and using it more. Note: the flue in the picture is sealed with plastic at that time in order to keep stink bugs out (annoying pests!). I would appreciate knowing what people think, is this a problem? Is it safe to use?

Thanks

 

[pen]

From the little bit that is seen of the bricks in the chimney, I have questions about the whole setup.

Roofing tar is not meant for that application, but more needs to be seen of the whole setup to give a better picture of safety for that chimney.

 

[Robb]

I have attached another photo that shows a little different angle. The fireplace is about 25 years old. The exterior of the fireplace is stone which seems to be in decent shape; however, the mortar between the stones shows evidence of water damage with some gaps and cracking. We used a urethane caulk to seal what we could see. I suspect the crown has leaked in the past and caused the damage to the mortar. It doesn't seem to be leaking now; however, I question whether the roofing tar so close to the flue is a fire hazard and should be replaced before any further fires in the fireplace. If we replaced it, I wouldn't be surprised if we had to replace the whole crown since it is pretty crumbly under the spots where the tar cracked.

 

[begreen]

Your concern is valid. Tar does not belong up against the flue tiles. A proper crown has no tar on it.