Concrete slab expansion joints

[hammertoad]

Just had a 32 x 24 garage foundation poured. Within 48hrs. they came out and cut the expansion joints. They cut two within the 32 ft. length. The put them in the position of the piers, between the location of the three garage doors. the cuts go from the back of the slab out and across the 2 ft. apron. I would have thought that they would cut them within the actual foundation and one between the foundation and the apron, not thru the 2ft of apron. In other words cut a joint to seperate the apron from the garage. and two within the garage. What is the proper or suggested way?

[mjpliv]

If I understand your desicription then your concrete man got it right. You should have two cuts running from between the doors to the opposite side (24 feet away).

[Tom R]

It sounds correct, though you may think it 'unsightly' now, it's giving the concrete a place to crack, rather than even more 'unsightly' random cracks later. There should also be one, as you say, between the 'slab' and the 'apron'. You can fill the 'cuts' with a light gray, self-leveling polyurethane caulk, it's much more appealing to the 'eye', and prevents the opening from filling with debris and disallowing proper 'expansion'.

[Rich]

Just to clarify for others..
Expansion joints are located between one structure and another structure - typically. What you're describing is a control joint. Which essentially "controls" where the concrete will crack. Sometimes saw cut and other times tooled.

[mjpliv]

Am I correct in assuming we are addressing control joints in this thread. Thats the way I answered it. If it was expansion joints (not required in this building) - oops! Sorry about that! :oops:

[Tom R]

I, too, am addressing 'control joints'. Once Rich mentioned it, I went back and re-read the original post, and sure enough, it says 'expansion joints'. It's good for the 'mind' to make the automatic correction, but not to jump to any conclusions. Hopefully, we fell in the 'correction' category. Good catch, Rich!

[mjpliv]

Rich knows all.... sees all! Kinda spooky actually! 8)

[Rich]

LOL
Most of the time I read right past stuff like that.