New garage time!

[buckeyefarmer]

My front porch has control joints but still has cracks elsewhere.

Basement has no control joints and I’m not aware of any cracks. Mostly covered in carpet now so can’t see if there are

 

[Kyle_in_Tex]

Interesting discussion. Down here, like Eddie says, they don't cut slabs for the homes.

 

[fatjay]

I’m certainly no expert, but I’m with Eddie on this one. Hard clay, stomped crushed stone, rebar and wire in the middle, driest mix possible, foam on the sides, and a joint across the middle, plus it will never get below 55F. I’ve kept it submerged in water the past 3 days and will continue until Monday. As far as I can tell I’ve taken every possible precaution. Once I have a roof over it it’s being painted with epoxy.

The whole thing ended up being 7-8” thick as well. Time will tell, I’ll report back if any cracks do appear.

 

[MossRoad]

I’m certainly no expert, but I’m with Eddie on this one. Hard clay, stomped crushed stone, rebar and wire in the middle, driest mix possible, foam on the sides, and a joint across the middle, plus it will never get below 55F. I’ve kept it submerged in water the past 3 days and will continue until Monday. As far as I can tell I’ve taken every possible precaution. Once I have a roof over it it’s being painted with epoxy.

The whole thing ended up being 7-8” thick as well. Time will tell, I’ll report back if any cracks do appear.

I didn't see a picture of a joint in the middle. How did you do it?

 

[EddieWalker]

I didn't see a picture of a joint in the middle. How did you do it?

He poured it in two days.

 

[ovrszd]

I took it to mean what means of making the splice? Just pour up against the other pour or some sort of expansion material. But I might be overthinking the question.....

 

[MossRoad]

He poured it in two days.

I didn't see a picture of a joint in the middle. How did you do it?

I took it to mean what means of making the splice? Just pour up against the other pour or some sort of expansion material. But I might be overthinking the question.....

That's what I thought. And, I'm not sure that pouring new concrete against hard concrete would qualify as a controlled crack area unless there is some depth to a cut made into the concrete along that joint line. Unless a cut is made, it will be hard as a rock. It's not like it's laying there against it. It's adhered to it with the concrete. Granted, there's no rocks spanning the line between the two pours, but I still wonder.

Anyhow, if it does crack, he's got plenty of rebar to keep things together and prevent shifting, raising, lowering, etc... that would affect the piping. All-in-all, he's gonna be happy. Let's check back in 20 years and do a core sample of the jointed area. :laughing:

 

[dragoneggs]

I don't know if the seam is clean/straight between pours and I am guessing not very. But this would be a great place for a controlled crack location. That said, I think OP did a great job with the reinforcement... far better than most, and if he is on hard pan with the gravel base, he could very well live to never see a crack.

 

[EddieWalker]

In my opinion, and it's just that. I don't think that concrete moves very much. On two slabs this size, it would be just about impossible to measure the amount of movement that is happening. I'm thinking there will be a lot of zeros in that measurement!!! Since the movement will be so slight, that seam will provide the relief that the slab needs. If this was a driveway, exposed to the sun during summer, and freezing temps in winter, I would want something more substantial between the slabs because the movement would be a lot more. In this case, taking everything into consideration, I think he's fine just the way it is.

 

[ovrszd]

Yep, probably true. I'm thinking the surface finish is going to be a much bigger issue in the future than cracks.