**control Joints**

[groove grabber]

Let me get this right:

1.All concrete should have control joints in place
2. The cuts should be approx 25% of slab thickness
3. Every 12-15 ft is sufficient.

Ok hears the questions:

1. I have a concrete saw, what blade do I need for 3 day old concrete?
2. Is 3 day old concrete to late to cut ?
3. Do I cut all the way to the edge, or is within an inch ok?
4. I will epoxy, whats the filler I need

I have searched for answers, almost to point of overload, you guys of late have helped me very much, whats your thoughts?

 

[Kevin54]

3. Do I cut all the way to the edge, or is within an inch ok?

You can't get all the way to the edge with a circular blade

2. Is 3 day old concrete to late to cut ?

No

1. I have a concrete saw, what blade do I need for 3 day old concrete?

Just the standard blade that you always use.

 

[nonhog]

I used a circular saw with a ceramic blade way past 3 days . It was tough, real tough, but it worked .
My right forearm looked like Popeye when I was done .

 

[boiler7904]

Your first three statements are correct.

Answers to your questions:

1. Probably a diamond blade. You could use an abrasive blade but you'll need a lot of them.
2. Not too late. The longer you wait, the more the concrete will cure and the harder the cuts will be to do.
3. If you can't get to the edge, the concrete will crack to the edge.
4. Depends on the epoxy system you plan to use. Talk to their tech services people.

 

[SULLY]

I had a company do my epoxy.
He asked me if I wanted the joints filled.
I asked him about cracking and he told
me the concrete would crack before the
epoxy. I had them filled and within 2 years
two of the three had cracked.
Instead of a nice straight cut they now have
a zig-zag crack. Shows up pretty good on a
nice glossy floor.


Sully.........