Slab Crack Control Lines - Scored or Sawcut?

[Norcalz71]

Anyone have a preference? We are hopefully getting started on grading for our new 1200 SF shop building in the next week or so, but that has not been decided. The space is a 30x23 "front" with a 22x23 stub out the back-right, so an L shape. Purpose will be storage for our boat, 1-3 trucks/toys, motorcycles, and workshop space.

 

[LegacyIndustrial]

I don't want to interfere with the concrete guys.
However, from my own knowledge and points of reference you should saw-cut 1/4 the depth of the slab, while very green (next day) and the areas should not exceed 12' x 12' .

Hopefully, one of them can confirm my attempt.

Good luck!

 

[Kaizen]

I prefer sawcut. Did mine myself with a chalk line, piece of plywood as a straight edge, and my circular saw with a new 25 buck diamond blade. Worked fine. One issue I had was when I went to fill with caulking stuff (I know not caulk but can’t think of term) the cut was so thin I couldn’t get even small foam backer rod down it. In the finished floor the cut goes up to the pipe as far as the saw could go and then on the other side. So from the left to the right in picture. Barely detectable

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[Kaizen]

I don't want to interfere with the concrete guys.
However, from my own knowledge and points of reference you should saw-cut 1/4 the depth of the slab, while very green (next day) and the areas should not exceed 12' x 12' .

Hopefully, one of them can confirm my attempt.

Good luck!

Correct from my research as well. Sections should be uniform size. My 30x36 I did nine 10x12 sections. Decided on size so I made sure a future lift did not land near a cut


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[lakeroadster]

Here's a great article for you Norcalz71...Be Active in Deciding Where Control Joints Will Be Placed

 

[Falcon67]

I put down 960 sq/ft and not a cut one.

 

[Armorpoxy]

Hint...if saw fits are too small to get backer foam in them you can fill with sand and run a screwdriver through the sand keaving about 1/4-3/8" of depth to fill with joint filler. The sand acts as the support!

 

[Norcalz71]

10-4 thanks guys and I will have to check out that article. Lift is "unlikely" but we are thickening a section just in case for future.

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[larry_g]

https://www.garagejournal.com/forum/showthread.php?t=375371

In the above thread I explain how I used zip strips and have been happy with the decision in 2 shops.

lg
no neat sig line

 

[Lelandwelds]

Hint...if saw fits are too small to get backer foam in them you can fill with sand and run a screwdriver through the sand keaving about 1/4-3/8" of depth to fill with joint filler. The sand acts as the support!

There is a polymer sand which sets up and wont wash out. They use it on cement pavers. You wouldnt need much.

There is a plastic piece they place instead of saw cuts. From the end, it was shaped like an arrow and looked darn easy to install. The one I saw was almost exactly the color of wet concrete. A week later it was flush and almost invisible.