Chimney brick question

This chimney was recently pointed, but my question is about the slight crack in the one brick, and the staining on the tarring beneath it. Two stains, one whitish, other reddish. What can this be from, any concerns. Thanks

Can’t tell you, but my question to you would be why the tarred section on the bottom?

Is this a basement?

All I can see is that it probably has a 8"x12" flue.

Rust may possibly be that the tared area is over a clean out door??

That tar is suspect of hiding something and never saw such a straight crack before.
Also would mention the window at lot grade.

No clean out at the inside?

Thanks for comments. Im thinking something was going on under that tar at one point as well. As for the window at lot grade,they got that covered with the plexiglass shield, I’m sure that a newfangled water diverter:)

The base of the chimney is or should be concrete.
It has been anti damped or plastic cement applied to the concrete.

It will cause the concrete to degrade at a faster pace. Question is faster pace than what???
Concrete/masonry above grade should have the ability to shed RH/water it absorbs.

That crack maybe a sign to interior chimneys condition.
Not a nice pointing job. As long as it works.

The staining; #1 The white is from the mortar mix in my eyes, to white for concrete or cement. Be damned it they added white dye.
#2 The brown looks like it is from the chimney itself. Bleeding from the cracked brick.

The chimney liner and inside void will be filled with solid or liquid fuel residue.
Recommend fill the crack.

SUSPECT: Water may be entering the crack and residue from inside the chimney be washing out onto the chimney base.
Look I can not see it that clearly.
he brown staining can also be from the anti damp or plastic cement. The bitumen tar will leach out oils that will wash down the chimney base with the rain.

I would soft write a chimney sweep and chimney inspection.

Limitations on your report are recommended. IMO

LIMITATIONS: This report does not include the chimneys inner condition. It is an visual observation of the exterior components and connections.

All the best.


I rarely see a chimney clean outs on the exterior
In my neck of the woods they are on the inside. It would be below the furnace flue connection into the concrete base.

I have rebuilt furnace chimneys. If there is no liner the brick become so embedded with oil based residue it becomes a issue. the unburned carbons or soot leaches into the masonry bedding. I have seen brickies point the bedding and butt joints out to hide the staining.
Dirty Flues and Chimneys

Soot gathers at the base and on the walls of both metal flues and masonry chimneys that vent smoke from oil furnaces. If the base of a metal flue is not cleaned, the soot can burn, producing toxic carbon monoxide that can spread through the ducts to all parts of your house.