Control Joints

[thirdgoat]

I just had my 30x50 concrete slab poured yesterday, and they used a saw to cut the control joints. After the building is completed, I plan to finish the floor. Is there a way to "round off" the control cuts a little bit so they aren't as susceptible to cracking off? Pretty sure I could use an angle grinder, but something that could cut both sides at once would be better.

 

[rustyjames]

I would try a rubbing stone used on masonry, the sooner the better, before it gets too hard.

 

[RustyJunk]

I would just fill them in with some urethane caulk.

 

[TTMotorsports]

Fill the joints with sikaflex and it really helps with that. Only a couple small spots have cracked on mine since i put sikaflex in them. And those i'm 99% sure were already cracked before but not broken off.

 

[ConCretin]

I'm not aware of a way to round off the edges of a saw cut control joint. You could open up the cuts with a crack chaser bit, which would soften the edges a little and facilitate caulking but you'll still fairly sharp have edges that could ravel. The best thing you can do is cure the floor properly and stay off of it until the concrete has gained some strength. It shouldn't be much of a problem after that.

 

[matt_i]

A rub brick woould make pretty fast work, but I'm in the camp to leave them alone. Otherwise its going to be a divot that catches everything ever rolled or slid across.

Unless you put a wedge anchor right next to a saw cut or struck a sharp blow they are pretty tough. I haven't cracked any corners with a 12,000 lb forklift rolling over them.

 

[ConCretin]

I would try a rubbing stone used on masonry, the sooner the better, before it gets too hard.

A rub brick woould make pretty fast work, but I'm in the camp to leave them alone.

What am I missing? How is a rubbing stone going to do anything to an 1/8"- saw cut?!

 

[ItsNemo]

Don't try grinding or cutting or doing anything to them....let them harden first. Otherwise, you will break pieces off.

I also like the idea of caulking them.

 

[Kaizen]

Silkaflex is rock solid. I did as was said above and haven’t had any chips


Sent from my iPhone using The Garage Journal mobile app

 

[joes169]

There's a couple of options I can think of of the top of my head.

The fastest, easiest, and best approach would be to find a "Soff-Cut" 150-D saw to chase the joints. They make a "V" blade as well as a radiused blade meant to replicate tooled control joints. The problem is the saws are rare and expensive.

You could also close the joints up with a semi-rigid joint filler. We use this material occasionally on factory floors for heavy forklift and steel wheel traffic, to control spalling at the joints.

You could also chase the joint with a 4" crack chaser blade in a grinder, assuming the concrete isn't still green. The issue is that it's hard to hold a decent depth with them, unless you can set one up in a circular saw?

https://www.ediamondtools.com/produ...1_QRwTyE49k3LhNygpbQ_-lv5eMSw4cxoCvQ0QAvD_BwE

To be perfectly honest, I don't think I'd mess with any of these though if it's just a regular, lightly used garage floor. Decent concrete should hold up fine to light use.

 

[brownbagg]

pack them with a tile grout

 

[wssix99]

There are products specifically for filling these: https://www.ardexamericas.com/product/ardex-ardiseal-rapid-plus/

Just wait 30 days until the majority of the shrinkage has occurred and then fill. If you are going to epoxy the floor, then there are different products (similar to grout) to use.

 

[rustyjames]

What am I missing? How is a rubbing stone going to do anything to an 1/8"- saw cut?!

I've seen cracked joints as the OP is referring to. To answer his question I was referring to using one of these on edge: https://www.acetool.com/Marshalltow...b7&gclid=COiGt7qby-QCFYviswodAb4I-g&gclsrc=ds