Hairline cracks in back of chimney.

[Ctwoodtick]

Doing some spring cleaning, I moved some items away from the back of my masonry chimney that have been there for several years. I noticed a couple of hairline cracks, but I have not noticed or paid any attention to before. I wanted to put a couple pictures up to see what people thought of them. I put a level on what I think is the foundation of the chimney. On the side of where the cracks run towards, it looks to be dead level. On the left side of the cracks, it appears slightly on level going towards the direction of the cracks. I’m including a picture so that you all can see where the bubble was on the level. Thanks for any insights.
The two different hairline cracks appear to be roughly one on top of the other with a little space between where I did not notice any continuous cracking. The rest of the outside of the chimney appears OK.
For reference, the House is 50 years old

 

[Whitenuckler]

Doing some spring cleaning, I moved some items away from the back of my masonry chimney that have been there for several years. I noticed a couple of hairline cracks, but I have not noticed or paid any attention to before. I wanted to put a couple pictures up to see what people thought of them. I put a level on what I think is the foundation of the chimney. On the side of where the cracks run towards, it looks to be dead level. On the left side of the cracks, it appears slightly on level going towards the direction of the cracks. I’m including a picture so that you all can see where the bubble was on the level. Thanks for any insights.
The two different hairline cracks appear to be roughly one on top of the other with a little space between where I did not notice any continuous cracking. The rest of the outside of the chimney appears OK.
For reference, the House is 50 years old

Probably normal as things settle over time. Is it a liner inside or clay tile?

 

[Ctwoodtick]

Probably normal as things settle over time. Is it a liner inside or clay tile?

Liner.
Good thought, I imagine if it was clay, that could crack over time too. I had the previous clay removed to keep the stainless liner in the round and for room for insulation:

 

[EatenByLimestone]

I’d probably take a look at it every year or 2. I personally wouldn’t get worked up over it. If you’re ever really board and have absolutely nothing to do you can repoint the joints and that may stop the mortar from cracking for a while.