Found a picture from the fall right after I finished the landscaping about 10 days after the patio was finished.

The blue lines are the joint that cracked off from the rest which appears to be 1 piece on it's own now, joint in the middle of this section did not crack i'm pretty sure but will have to double check.

The red section on the right dropped 5.25mm away from the house in that area.

Section on the left rose up on that corner 3.5mm.

Not sure if this will help, if not I can get more detailed photos later.

After seeing some of the related discussions that popped up with this, i'm aware this is a minor issue but am more worried it is telling to the quality of the work.

Happy to provide more info, just need to know what is helpful.

Thanks in advance!

Does "... dropped 5.25mm away from the house ..." mean that it sunk in elevation ... or mean moved away horizontally? Usually, if you can show the exact things in pictures, it saves a lot of questions.

Control joints exist to induce cracking along a specific line, rather than just anywhere. If this is more or less hairline crack along the joint, it means nothing bad.

Is there reinforcing wire in the slab?

(I will not have access to Internet until much later.)

The best way to describe it would be that the rounded corner on the right side of the photo sank on the x and y axis.

Control joints did their job in controlling the crack, my concern is should they have caused the slab to rise and sink in two spots as much a it did, so early in it's lifespan.

Reinforced with welded wire mesh.

The most important part of any paving is the base, so I'd be interested to know what was used here, the thickness, and if it was properly prepared and compacted. Also, what type of soil it's on, and if that was compacted as well.

Is this due to frost heave do you think, if so the base wasn't adequate?

Previously the area had a small concrete pad that had a deck built over the pad. The Deck was sagging when we bought the home and we found that the deck supports sitting on the very end of the original pad had cracked it. The base from the original concrete pad was used and expanded upon which was made up of mainly sand it appeared. It was compacted and poured at 4" allowing proper time to cure and dry.

Soil in our area is a lot of clay but the the top soil that is used with grading is a large amount of sand.

The general contractor we used is a friend and does not seemed concerned with anything his concrete team did or didn't due and said it is most likely happening now because after the very wet May/June we had, it is now getting really dry and will most likely move back once it is wet again.

So he is suggesting that it is the drying out of the clay that has caused the movement? Clay expands when wet and contracts and goes hard when it dries out if this is the cause the diagnosis is the same, inadequate base.

The mesh is to prevent separation so this should not become bad. A crack can occur early on in the life of a slab, so I don't think out of bounds, and it seems relatively minor. I would not stress about it. If it worsens later, there are a couple of options to fix, but I would not apply until a couple of years have passed to see if it's really needed and enough time for any settlement to finish has passed.. (One fix is grinding. The other is jacking.)

Just an update on this. The slab had additional movement of 3.5mm down in one spot and 3.5mm up on the opposite end. We have been getting some rain over the past 2 weeks and I have noticed that it has been moving back to be level and suspect it will even itself out or come close. Would jacking be worth it or will this happen every summer when it dries out?

I think you will need to test some summers in order to get the answer. The question is akin to asking the surgeon if the tumor will return within a specified time frame. He's not going to know. And you have some variables that only forensic testing could hope to learn.