Should I make a center cut?

[robertwhite]

So, after several months, I cut lines into my slab on the width dimension (24ft). The lines are 1/2" deep and cut every 11' down the 88' length. There is also a cut at the roll up door where the ramp connects. The ONLY reason I even made the cuts is because when the slab was poured, the contractor did not put a cut line across the ramp/slab meeting point and the ramp developed a single hairline up and into the slab about 8' or so. If there was a separation cut, it would have never cracked the slab.

In any event, I made the cuts to avert the hairline from running the length of my slab, BUT, I am still debating whether or not to put a cut down the middle (12' on each side) and if so, do I stay away from the section in which the 2 post lift will go. If I make a centerline cut, the cut line would be about 5' away from either post. I would imagine that is far enough, but in my mind that is now creating 2 separate slabs that the 2 post is attached to.

The cross cuts are between 4-5' from the posts which will sit 15' (to center of post) from the door.

What say you?

 

[ConCretin]

Saw cut control joints are most effective when they are cut immediately after the slab is placed and 1/4 of the slab thickness in depth. You also want the 'panels' created by the cuts to be as square as practical.

One additional cut in the long direction won't do any harm but if you haven't got shrinkage cracks at this point you probably won't.

 

[robertwhite]

One additional cut in the long direction won't do any harm but if you haven't got shrinkage cracks at this point you probably won't.

That is why I am so annoyed about the crack from the ramp. There are no cracks anywhere else and I would be willing to bet there would never be any. Now I have to make all the cuts because of that hairline from the ramp.

It also brings to mind the question I asked. I would have much preferred to have no cuts at all.

 

[Dan Timberlake]

I think most codes talk about cuts every 30 feet or so, and at inside corners

 

[robertwhite]

I think most codes talk about cuts every 30 feet or so, and at inside corners

Codes?

I live in the sticks. I can build a new house and not need a permit.

 

[BADSIX]

you'll get cracks i took almost 3 years before i got cracks i both of my house garages. a contractor told me that its not if its going to crack its when