Concrete control joints - newbie help

[gamp945]

Hi all,

I am brand spankin new to concrete work. I appreciate anybody who can answer my mundane question about control joints!

I recently had a new driveway poured. The driveway sits in between a retaining wall and the house foundation. The concrete guys began/ended the control joints about 6" away from both the retaining wall and house foundation. I think this is because their saw was too large to get any closer.

I assume that a crack will form in between the retaining wall or foundation and where the control joint begins. Won't this crack be pretty crooked and random? Should I try to get a smaller saw and extend the control joint as close as possible to the wall and foundation? If so, any recommendations on the best tools for this job?

 

[ConCretin]

You are correct about the likelihood that a crack will form from the end of the saw cut to the wall. I'd take a 4" grinder with a diamond cutting disc and extend the cut as close to the wall as you can. That's about all you can do.

 

[wgasa84]

One issue besides the saw cut not going completely up against the wall is it doesn't appear they put an expansion joint up against the wall. Those will move separately and it crack can be caused by no expansion.

The saw cut can only get so close as the 4" grinder will allow.

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[gamp945]

I just looked now and see 2 of the joints have already developed a hairline crack from the joint to the wall. They are both very straight.

I have a 5" angle grinder. I also have an OMT. Is it ridiculous to think about using the OMT for the job?

 

[ConCretin]

Ok, maybe I'm the only one but wth is an OMT? I must need one.

 

[wgasa84]

I just looked now and see 2 of the joints have already developed a hairline crack from the joint to the wall. They are both very straight.

I have a 5" angle grinder. I also have an OMT. Is it ridiculous to think about using the OMT for the job?

I would think the OMT would take forever to make the cut.

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[wgasa84]

Ok, maybe I'm the only one but wth is an OMT? I must need one.

Oscillating multi tool [emoji6]

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