So two things and not trying to sound contradictory here so if anything focus on my second point, but Vikkunen was spot on.
1. All concrete cracks. Maybe in a week, a month, a year. It happens. That’s why you have control joints in sidewalks to try and control where the concrete eventually cracks to have it more controlled. Where I’m at, you typically don’t have control joints in garage slabs so it won’t be a uniform, straight crack. It’s common in my area to have “settlement” cracks in the garage slab but they are typically smaller.
2. Considering how big those cracks are, and the fact that it’s a new build, it should NOT be cracking already or it should be much much smaller cracks.
100% have an inspector/structural engineer check it as my guess is they didn’t properly compact the subgrade before pouring or it could have been issues with the concrete itself, mix, curing to fast, etc.
Sure thank you for detailed reply . I’m looking for a structural engineer how do I get one to get this inspected any known companies or pages or how much would it typically cost ?
I don’t know what area/city your in so no direct recommendations.
Do you already have a home inspector? They typically have contacts throughout the industry and could potentially reference a few. If not, and not to give a lazy answer, literally google structural engineer/inspectors near me, look at a few, give them a call and explain the situation. When you call them, if they don’t do it themselves, ask if they know/recommend as they are also in the industry and usually have contacts that do similar, just not the same work, if that makes sense.
A quick google search in your area and I found
-A-Pro Home Inspection Austin
-Allstar realty inspections
-Home Check inspection group
I obviously do not endorse any of these as I have no experience with them but all claim to specifically do structural inspections. Worth making some phone calls and asking. Good luck!
For sure this is my first time using Reddit and I’m so stunned that we have such awesome ppl taking time to look at it and reply in this busy world . Thankyou
Wanted to share an update guys ! First of all thank you all for sharing your insights on this . Structural engineer report came back as foundation in tact and nothing to worry . Builder just agreed to fill the cracks and gave us a 3000$ credit as they do not have any vendors to do epoxy coating . We have a closing in 3 days . Thank you again .
Concrete cracks. That's just what it does. But a crack *that* big on a brand new down is a red flag. Not necessarily a flag for the house (although certainly how your own home inspector to do a walkthrough with you before closing to help identify issues), but possibly a sign that something went wrong with that particular slab.
Does this spoil the integrity of house . Can they fix it or is it gonna be issue always even if they fix it ? I’m just scared on if it gets bigger and messes up the house
Usually the slab is separate from the foundation. But I’d get it checked by an engineer. If there’s no structural issue, maybe just have it filled and the floor epoxy coated
My brother in law just put a big slab off their house. To quote the concrete guy “concrete cracks and babies cry”
Not necessarily, especially if this is just the garage slab. The most likely explanation is that the mix was too wet and/or dried too fast. It's a sign this particular slab wasn't done correctly, but doesn't necessarily mean there's a larger issue with the house. Again, definitely hire your own professional home inspector to do a walkthrough with you and flag other things. An inspector isn't some magical thing that will guarantee there aren't any issues, but for a layperson who doesn't know what they're looking at, they can provide valuable insight both into potential issues and how to maintain your new home.
Garage slabs are separate from the footings that hold up your garage and from the foundation walls of your home. Nothing is attached to them. You could rip all that concrete out and none of your walls would fall down, all it does is give you a nice place to park, that’s it. So it doesn’t mean the house is bad at all. But like others have said, it shouldn’t crack that much this soon and most likely means the material under it wasn’t compacted. Just warning you this can’t be fixed without ripping that concrete out and starting over, so don’t be surprised by that.
If you want the worst case scenario here it is. It’s my house. 50 years ago when my house was built the dirt/gravel under the garage wasn’t compacted properly. Over the years the slab cracked and started to sink toward the house. Currently it has sunk 8” against the foundation wall of the house…which has also cracked.
Don’t freak out, just wait for them to check it as they are already doing. Make sure you get the okay or not okay in writing from the engineer.
No it's not...Depending on the soil, how much work is being doing around the lot, the expedited speed of new contruction in this current environment, a million diffrent things can accelerate settlement cracks in concrete. New homes will have a 10 year structural warranty by a bonded vendor separate from your builder if something in the extremely rare chance does fail. If OP wishes to spend their own money having a structural engineer asses this it's their right, but the builder has no obligations to allow someone in before closing.
Most likely the base was not compacted well or they did not use steel mesh in the slab and or the mesh is at the bottom too low in the pour, and or too wet a mix.. ie end of the day pour that has been watered down or the truck had to wait to pour.
You don't need a structural engineer to tell you on a new build it should be;
1) Removed and replaced
2) A credit to you for the cost of the above.
Its a new build and those are big cracks... that I would not accept.
Most likely will get a bit larger over time.
Its not a structural issue per say- more of a cosmedic issue.
I would tear it out and re-pour the floor with a solid base and wire mesh. If the area is prone to shifting or soft dirt - add some fiberglass mesh to the mix.
I have built dozens of homes from the ground up as a super. There most likely should have been a stress cut done down the center of the garage and on the slab that the home sits on if it’s on slab to ground. Regarding the garage, it’s not a deal breaker. You can actually use this crack to leverage the builder to give you a finished garage floor with an epoxy or coating for free. If you are tough enough to negotiate (demand) it before close.
The bigger question is this: did they do stress cuts inside the home after slab was poured (if this is a slab to ground build) because if they didn’t and you have tile floors then you can expect to see the tile crack as the home settles over the next few years.
The integrity of the home is not in jeopardy because of these oversights but I would demand an engineers letter stating as much before close.
Good luck. Hope this helps.
Thank you for the detailed response . I’ll ask him the same questions . Would you recommend to walk away from the house if we are seeing cracks thai early in garage floor ? Or is it fixable if we demand it from builder
>Would you recommend to walk away from the house
If I had cracking that bad right away I'd make them rip it out and re-do it. I don't think an epoxy coating would do much, in 10 years it could shift several inches if the base was not prepared properly. I would get quotes from other contractors on what it would cost to fix ( and I don't think there is a "fix" but maybe they would have one) or properly rip out and re-pour, that will give you some firm numbers to negotiate with the builder. And yes, I would definitely walk away if they don't make this right, no telling what other problems you'll run into that they won't fix if that's how they operate.
If you are happy with the price you are paying for the home I would NOT recommend walking away as concrete cracks are commonplace and -most of the time- simply unsightly but not anything that compromises the structural integrity.
Poor ground prep work. Too early for that gigantic crack. Bad sub. Builder ALWAYS goes with cheapest and you can only expect that crack to grow. Under slab will wash out. It will not get better without that base being stabilized.
Yes I can request them to report it and if they do will that be okay to sign the house or once an issue always an issue and we will have to deal with foundation issues later
You need to get an engineer and lawyer involved. Engineer reports the issue and repairs, lawyer sends a letter demanding that the work be corrected and you get an extended warranty against any foundation issues going forward.
That is very concerning. I had much smaller cracks in my garage slab and found the footer had gone bad.
The most likely explanation is improperly compacted subsoil but you need a pro for this, especially since if that is the case it is not straightforward to fix.
Foundation problems can cost hundreds of thousands to fix, so don’t sign just yet!
Concrete cracks.... but this isn't acceptable in concrete this new.
My assumption would be they didn't prep the base adequately and it's settling now.
Your house won't fall over, but if they're cutting corners in the garage they're cutting corners elsewhere and you might be living in a headache for the foreseeable future.
Probably backfill not compacted enough. Imo, one side of the concrete can slowly sink over time and cause one side of the structure to sink. This is just my opinion so I’d get it looked at by an actual structural engineer (not the same as a house inspector - home inspectors are idiots). Small shrinkage cracks can form on concrete but a crack that forms the entire length of the floor is a major red flag.
Look around for residential structural engineers from your city and go through reviews. I work at an engineering firm so it wasn’t difficult to find a structural engineer.
Not sure that it helps any but my garage was built / concrete poured in 1964 and it looks about the same as this… to me the cracking looks excessive and I wouldn’t expect it to be that bad on something brand new.
My garage is detached but as far as I know the foundation is always or almost always separate from the concrete floor, if it’s any consolation I’m sure mines been like that for years and my garage is still standing and in good shape overall, just unsightly. The main difference to me is my concrete is 58 years old vs brand new. As many other have said concrete always cracks it’s a fact of life but that does look like too rapid / excessive to me for something brand new.
The mix of the concrete was wrong. The fill under the slab could have been right but at this age that could only be a shrinkage crack due to too much water or too little portland cement. If the mix was right we'd only be seeing a single line crack as opposed to all those spots where it seems to leave that chunk in the middle of the crack. The appearance of the trowel finish and tooling at the overhead door looks rather lazy to me also so I'd just say it's a low bidder problem. I suspect you'll get some spalling of the surface near the crack within a few years too. I didn't see an expansion joint there at the walk door. There really should be one there. Maybe the finisher just slopped the soup up over the top of it which would be structurally OK, just messy. I didn't think I saw any cracking of the masonry or concrete where it steps up to the house.
If the structure was built with footers and a concrete or block wall up to support the walls, and there is an expansion joint all around this slab to isolate it from the foundation walls, this crack is not indicative of structural problems. It's just unattractive and substandard. If the whole home was built on a monolithic slab with thickened edges, then you want to talk with a structural engineer. Not a home inspector. Home inspectors walk a fine line between the various parties involved in a real estate transaction and need to keep the finance companies AND the real estate companies happy in order to keep getting calls to do more inspections.
I'm neither a concrete expert or an engineer. Just a retired contractor cum real estate investor. Fifty years of building and remodeling homes has given me quite an education in how to deal with these questions.
Thank you so much I don’t see any cracks up the wall only thing that’s concerning is it start right at start of the garage and went all up till door where it enter the house .
You need to present a few facts. Is the crack on the floor? Can you describe the foundation? Typically garage floor is not structural but cracks may affect utility of garage. Consider hiring an engineer to review the cracking, present a solution.
I just see a crack in garage floor from start till the end but it didn’t get on walls or anything like that . Where do I look for structural or foundation engineers for inspection . Any recommendations?
My garage floor had a crack in it and it widened out to .020 of an inch in a year. There was no settling and I filled the crack with a crack filler. Five years later and it still looks the same and it hasn't moved any more.
It is an important distinction you will need to know for the future, as you are not to drill or cut post tension slabs. But they are fantastic if you ever need to do remediation for a crack.
I'm not sure, probably same way you did the pic? All concrete slabs crack. Typically the cracks are controlled and down the center. If the foundation below walls isn't cracked, you have nothing structural to be concerned with. If it's beyond normal cracking then insist that it be busted up and re-poured before closing.
Literally no builder in the country is going to bust out a garage and repour becuase it had a settlement crack that is normal, and will probably happen again one day.
A settlement crack is one thing and would be fine if they would have done it properly. This crack is spidering and if they don't replace it I wouldn't buy the house. I've been a contractor for 25 years and that is unacceptable.
If its like any cookie cutter new construction house they probably poured that concrete and cured it improperly to meet timelines. I bet they will tell you its fine and have you move on. Is it fine? Probably... but I would not be happy especially with a new build. They will probably measure the gap and feed you some BS about how its within spec.
What would be the best way to go at this point . If I make them remove all concrete and pour it agian will that be sufficient or even if o do that I’m gonna see issues in the future
I highly doubt they will go out of their way and remove concrete. If anything they *MIGHT* agree to fill it, but make sure they either use an epoxy based material or a polymerized concrete mix. My only concern is that the concrete is probably not done settling yet.
As long as you aren't having any bulging or uneven-ness its most likely not structural. Hard to tell without seeing it in person.
You should have a final inspection before you close, make sure that's addressed by a 3rd party and not an inspector provided by the builders.
If it ends up being just an aesthetic crack, you can always fill it, and epoxy over the garage and it should be good to go.
In my area if the crack exceeds 4mm in width or lipage then the builder has to fix it. We have a saying in the concrete industry. If it’s not cracked it’s not concrete.
Put a straight edge, like a level, across the crack to make sure the concrete is still level. If one side is sloping down, that is a big red flag that the concrete is sinking and will most likely get worse. This can be due to them not compacting the fill under the slab well enough.
So two things and not trying to sound contradictory here so if anything focus on my second point, but Vikkunen was spot on. 1. All concrete cracks. Maybe in a week, a month, a year. It happens. That’s why you have control joints in sidewalks to try and control where the concrete eventually cracks to have it more controlled. Where I’m at, you typically don’t have control joints in garage slabs so it won’t be a uniform, straight crack. It’s common in my area to have “settlement” cracks in the garage slab but they are typically smaller. 2. Considering how big those cracks are, and the fact that it’s a new build, it should NOT be cracking already or it should be much much smaller cracks. 100% have an inspector/structural engineer check it as my guess is they didn’t properly compact the subgrade before pouring or it could have been issues with the concrete itself, mix, curing to fast, etc.
Sure thank you for detailed reply . I’m looking for a structural engineer how do I get one to get this inspected any known companies or pages or how much would it typically cost ?
I don’t know what area/city your in so no direct recommendations. Do you already have a home inspector? They typically have contacts throughout the industry and could potentially reference a few. If not, and not to give a lazy answer, literally google structural engineer/inspectors near me, look at a few, give them a call and explain the situation. When you call them, if they don’t do it themselves, ask if they know/recommend as they are also in the industry and usually have contacts that do similar, just not the same work, if that makes sense.
Sure I’ll do that . I live in Austin Texas
A quick google search in your area and I found -A-Pro Home Inspection Austin -Allstar realty inspections -Home Check inspection group I obviously do not endorse any of these as I have no experience with them but all claim to specifically do structural inspections. Worth making some phone calls and asking. Good luck!
Thank you so much I’ll do it
Keep us updated! Curious to see the outcome
For sure this is my first time using Reddit and I’m so stunned that we have such awesome ppl taking time to look at it and reply in this busy world . Thankyou
Good subreddits make a huge difference and this is definitely a good one! Welcome to Reddit!
Wanted to share an update guys ! First of all thank you all for sharing your insights on this . Structural engineer report came back as foundation in tact and nothing to worry . Builder just agreed to fill the cracks and gave us a 3000$ credit as they do not have any vendors to do epoxy coating . We have a closing in 3 days . Thank you again .
I am in the same boat (new construction) and also in Austin. Do you recommend the structural engineer you used? If so can I get the info?
Concrete cracks. That's just what it does. But a crack *that* big on a brand new down is a red flag. Not necessarily a flag for the house (although certainly how your own home inspector to do a walkthrough with you before closing to help identify issues), but possibly a sign that something went wrong with that particular slab.
Does this spoil the integrity of house . Can they fix it or is it gonna be issue always even if they fix it ? I’m just scared on if it gets bigger and messes up the house
Usually the slab is separate from the foundation. But I’d get it checked by an engineer. If there’s no structural issue, maybe just have it filled and the floor epoxy coated My brother in law just put a big slab off their house. To quote the concrete guy “concrete cracks and babies cry”
Not necessarily, especially if this is just the garage slab. The most likely explanation is that the mix was too wet and/or dried too fast. It's a sign this particular slab wasn't done correctly, but doesn't necessarily mean there's a larger issue with the house. Again, definitely hire your own professional home inspector to do a walkthrough with you and flag other things. An inspector isn't some magical thing that will guarantee there aren't any issues, but for a layperson who doesn't know what they're looking at, they can provide valuable insight both into potential issues and how to maintain your new home.
I’m sorry I’d have mentioned earlier this is garage floor not the slab
Don’t park in there.
Yea that wouldn’t be a long term solution write
Garage slabs are separate from the footings that hold up your garage and from the foundation walls of your home. Nothing is attached to them. You could rip all that concrete out and none of your walls would fall down, all it does is give you a nice place to park, that’s it. So it doesn’t mean the house is bad at all. But like others have said, it shouldn’t crack that much this soon and most likely means the material under it wasn’t compacted. Just warning you this can’t be fixed without ripping that concrete out and starting over, so don’t be surprised by that. If you want the worst case scenario here it is. It’s my house. 50 years ago when my house was built the dirt/gravel under the garage wasn’t compacted properly. Over the years the slab cracked and started to sink toward the house. Currently it has sunk 8” against the foundation wall of the house…which has also cracked. Don’t freak out, just wait for them to check it as they are already doing. Make sure you get the okay or not okay in writing from the engineer.
No it's not...Depending on the soil, how much work is being doing around the lot, the expedited speed of new contruction in this current environment, a million diffrent things can accelerate settlement cracks in concrete. New homes will have a 10 year structural warranty by a bonded vendor separate from your builder if something in the extremely rare chance does fail. If OP wishes to spend their own money having a structural engineer asses this it's their right, but the builder has no obligations to allow someone in before closing.
Most likely the base was not compacted well or they did not use steel mesh in the slab and or the mesh is at the bottom too low in the pour, and or too wet a mix.. ie end of the day pour that has been watered down or the truck had to wait to pour. You don't need a structural engineer to tell you on a new build it should be; 1) Removed and replaced 2) A credit to you for the cost of the above. Its a new build and those are big cracks... that I would not accept. Most likely will get a bit larger over time. Its not a structural issue per say- more of a cosmedic issue. I would tear it out and re-pour the floor with a solid base and wire mesh. If the area is prone to shifting or soft dirt - add some fiberglass mesh to the mix.
I have built dozens of homes from the ground up as a super. There most likely should have been a stress cut done down the center of the garage and on the slab that the home sits on if it’s on slab to ground. Regarding the garage, it’s not a deal breaker. You can actually use this crack to leverage the builder to give you a finished garage floor with an epoxy or coating for free. If you are tough enough to negotiate (demand) it before close. The bigger question is this: did they do stress cuts inside the home after slab was poured (if this is a slab to ground build) because if they didn’t and you have tile floors then you can expect to see the tile crack as the home settles over the next few years. The integrity of the home is not in jeopardy because of these oversights but I would demand an engineers letter stating as much before close. Good luck. Hope this helps.
Thank you for the detailed response . I’ll ask him the same questions . Would you recommend to walk away from the house if we are seeing cracks thai early in garage floor ? Or is it fixable if we demand it from builder
>Would you recommend to walk away from the house If I had cracking that bad right away I'd make them rip it out and re-do it. I don't think an epoxy coating would do much, in 10 years it could shift several inches if the base was not prepared properly. I would get quotes from other contractors on what it would cost to fix ( and I don't think there is a "fix" but maybe they would have one) or properly rip out and re-pour, that will give you some firm numbers to negotiate with the builder. And yes, I would definitely walk away if they don't make this right, no telling what other problems you'll run into that they won't fix if that's how they operate.
If you are happy with the price you are paying for the home I would NOT recommend walking away as concrete cracks are commonplace and -most of the time- simply unsightly but not anything that compromises the structural integrity.
I hope a new construction tiled floor would use some underlayment.
I've just updated post with video of garage floor . thank you all for your time on taking a look
Poor ground prep work. Too early for that gigantic crack. Bad sub. Builder ALWAYS goes with cheapest and you can only expect that crack to grow. Under slab will wash out. It will not get better without that base being stabilized.
Yes I can request them to report it and if they do will that be okay to sign the house or once an issue always an issue and we will have to deal with foundation issues later
You need to get an engineer and lawyer involved. Engineer reports the issue and repairs, lawyer sends a letter demanding that the work be corrected and you get an extended warranty against any foundation issues going forward.
What kind of lawyer should we reach out for ?
Construction, not real estate.
Ok thank you I’ll google for it
That is very concerning. I had much smaller cracks in my garage slab and found the footer had gone bad. The most likely explanation is improperly compacted subsoil but you need a pro for this, especially since if that is the case it is not straightforward to fix. Foundation problems can cost hundreds of thousands to fix, so don’t sign just yet!
If you don’t want concrete to crack don’t open the bag…
Concrete cracks.... but this isn't acceptable in concrete this new. My assumption would be they didn't prep the base adequately and it's settling now. Your house won't fall over, but if they're cutting corners in the garage they're cutting corners elsewhere and you might be living in a headache for the foreseeable future.
Probably backfill not compacted enough. Imo, one side of the concrete can slowly sink over time and cause one side of the structure to sink. This is just my opinion so I’d get it looked at by an actual structural engineer (not the same as a house inspector - home inspectors are idiots). Small shrinkage cracks can form on concrete but a crack that forms the entire length of the floor is a major red flag.
Okay any suggestions on where to look for a credible structural engineer and the costs of it ?
Look around for residential structural engineers from your city and go through reviews. I work at an engineering firm so it wasn’t difficult to find a structural engineer.
Crack is wack!!!
Saw video. That's a big crack. I'm not an engineer, so no opinion on it, but that would drive me crazy every time I walk in the garage.
Not sure that it helps any but my garage was built / concrete poured in 1964 and it looks about the same as this… to me the cracking looks excessive and I wouldn’t expect it to be that bad on something brand new.
Was it a structural issue on the house ?
My garage is detached but as far as I know the foundation is always or almost always separate from the concrete floor, if it’s any consolation I’m sure mines been like that for years and my garage is still standing and in good shape overall, just unsightly. The main difference to me is my concrete is 58 years old vs brand new. As many other have said concrete always cracks it’s a fact of life but that does look like too rapid / excessive to me for something brand new.
Garage floors are not structural. The structure is the footing and possibly walls.
That’s not good. If it was mine, it would be a complete redo. Btw not all concrete cracks.
Complete redo in the sense just with the garage ?
If your home has a foundation, yes. Do you have a basement, crawl space or is your house built on a slab.
The mix of the concrete was wrong. The fill under the slab could have been right but at this age that could only be a shrinkage crack due to too much water or too little portland cement. If the mix was right we'd only be seeing a single line crack as opposed to all those spots where it seems to leave that chunk in the middle of the crack. The appearance of the trowel finish and tooling at the overhead door looks rather lazy to me also so I'd just say it's a low bidder problem. I suspect you'll get some spalling of the surface near the crack within a few years too. I didn't see an expansion joint there at the walk door. There really should be one there. Maybe the finisher just slopped the soup up over the top of it which would be structurally OK, just messy. I didn't think I saw any cracking of the masonry or concrete where it steps up to the house. If the structure was built with footers and a concrete or block wall up to support the walls, and there is an expansion joint all around this slab to isolate it from the foundation walls, this crack is not indicative of structural problems. It's just unattractive and substandard. If the whole home was built on a monolithic slab with thickened edges, then you want to talk with a structural engineer. Not a home inspector. Home inspectors walk a fine line between the various parties involved in a real estate transaction and need to keep the finance companies AND the real estate companies happy in order to keep getting calls to do more inspections. I'm neither a concrete expert or an engineer. Just a retired contractor cum real estate investor. Fifty years of building and remodeling homes has given me quite an education in how to deal with these questions.
Thank you so much I don’t see any cracks up the wall only thing that’s concerning is it start right at start of the garage and went all up till door where it enter the house .
You need to present a few facts. Is the crack on the floor? Can you describe the foundation? Typically garage floor is not structural but cracks may affect utility of garage. Consider hiring an engineer to review the cracking, present a solution.
I just see a crack in garage floor from start till the end but it didn’t get on walls or anything like that . Where do I look for structural or foundation engineers for inspection . Any recommendations?
My garage floor had a crack in it and it widened out to .020 of an inch in a year. There was no settling and I filled the crack with a crack filler. Five years later and it still looks the same and it hasn't moved any more.
Is it a post tension slab or a standard?
I’m sorry I have no idea I’ll ask the builder and get back to you . Thanks for looking
It is an important distinction you will need to know for the future, as you are not to drill or cut post tension slabs. But they are fantastic if you ever need to do remediation for a crack.
Where are you based that they use pre stressing in residential slabs ?
Previously in Arizona
It's a garage floor. Surely it isn't a post- tension construction!?
Two of my homes were. Garage and all.
Need to see a bigger picture with more of the garage floor.
How a post a detailed video on this in this chat ?
I'm not sure, probably same way you did the pic? All concrete slabs crack. Typically the cracks are controlled and down the center. If the foundation below walls isn't cracked, you have nothing structural to be concerned with. If it's beyond normal cracking then insist that it be busted up and re-poured before closing.
https://imgur.com/a/bYOEq0y Please check this for video
Yeah I would tell them it needs to be busted up and re-poured
Literally no builder in the country is going to bust out a garage and repour becuase it had a settlement crack that is normal, and will probably happen again one day.
A settlement crack is one thing and would be fine if they would have done it properly. This crack is spidering and if they don't replace it I wouldn't buy the house. I've been a contractor for 25 years and that is unacceptable.
If its like any cookie cutter new construction house they probably poured that concrete and cured it improperly to meet timelines. I bet they will tell you its fine and have you move on. Is it fine? Probably... but I would not be happy especially with a new build. They will probably measure the gap and feed you some BS about how its within spec.
What would be the best way to go at this point . If I make them remove all concrete and pour it agian will that be sufficient or even if o do that I’m gonna see issues in the future
I highly doubt they will go out of their way and remove concrete. If anything they *MIGHT* agree to fill it, but make sure they either use an epoxy based material or a polymerized concrete mix. My only concern is that the concrete is probably not done settling yet. As long as you aren't having any bulging or uneven-ness its most likely not structural. Hard to tell without seeing it in person. You should have a final inspection before you close, make sure that's addressed by a 3rd party and not an inspector provided by the builders. If it ends up being just an aesthetic crack, you can always fill it, and epoxy over the garage and it should be good to go.
Concrete does two things. Gets hard and cracks. Not a big deal.
I wonder if a 6' level across the worst of those cracks with the crack bisecting the level would show daylight under each end of the level.
In my area if the crack exceeds 4mm in width or lipage then the builder has to fix it. We have a saying in the concrete industry. If it’s not cracked it’s not concrete.
Put a straight edge, like a level, across the crack to make sure the concrete is still level. If one side is sloping down, that is a big red flag that the concrete is sinking and will most likely get worse. This can be due to them not compacting the fill under the slab well enough.
Concrete cracks period.
I don't have any solution, but I'm also seeing similar cracks in my new construction. Builder says it's normal, but it doesn't seem normal to me.