Filling expansion joints in concrete floor

[Myles Moran]

Jack, I used the Sika SL on my basement floor. My tooled control joint measured around 3/4" at the widest and about 5/8" at the deepest, and a case of 12 regular sized tubes was enough to fill about 50 linear feet of this in 2 layers. I also learned in the process exactly how unlevel my floor was despite looking level. In retrospect I should have put a level on my floor at the beginning instead of eyeballing it.

Part of my goal though was to air seal the slab so I didn't have any big cracks drawing air through it once I put a radon fan in. That was my big drive to caulk, otherwise I would have just grouted and called it done.

[Edward Weber]

You can tell that they are not expansion joints because they are only 3/4" or maybe 1" deep. The 3 or more inches of concrete below is solid.

An expansion joint, usually at perimeter or transition to other material, will have a strip of fiberboard or foam.

I have not personally seen the OP's joint in question.
Also every contractor does things differently OP said joint has 1/2" radius and shallow. I would think expansion rather that control.
Would be helpful to know if the joint is full or just 1/4-1/2 of the thickness. If it doesn't go through for movement or drainage, use the mortar method mentioned.
JMHO

[Cameron Wood]

I have not personally seen the OP's joint in question.
Also every contractor does things differently OP said joint has 1/2" radius and shallow. I would think expansion rather that control.
Would be helpful to know if the joint is full or just 1/4-1/2 of the thickness. If it doesn't go through for movement or drainage, use the mortar method mentioned.
JMHO

This is the type of tool used. I could dig out one of mine as well. Watch pretty much any concrete pour to see it done. The alternative is to wait for the concrete to mostly set, and cut the joints with a saw- also ~1" deep.

[Tom M King]

The best tool for the filling job is a Margin trowel. You can dip mortar out of a bucket, place it, and smooth it all with the same tool. They come in different lengths. The longer they are, the harder on the wrist. A lot of work can be done with a 5". That's my most used size. The Marshatown or Goldblatt ones with the synthetic handles are pretty easy on the hand.

https://www.amazon.com/GOLDBLATT-IND...ps%2C83&sr=8-7

I've worn out more margin trowels than any other type of trowel because they're the most used. I use them for every tile job as well as such as this one.

W. Rose is my favorite brand of masonry trowels. These are nice too. https://www.amazon.com/W-Rose-RO58-6...%2C132&sr=8-11

[Edward Weber]

Thank you but I know what a grooving tool is.
Again, I haven't seen the joint/slab in question, so no idea on thickness.
Guessing helps no one.
ACI recommends that a control joint’s depth should be created to 1/4 the slab’s thickness.
That's minimum of 1/4, so you need to know what you're working with if a joint going to have any effect.

I hope the OP gets the results he needs to make it safe.

[Tom M King]

You will also need knee pads. Most are sold today with straps above and below the knee. I never use straps above the knee, and any kneepads I buy with them get cut off before using. Try them out in the store before you buy any, and both try fastening the top straps and not to see the difference. They stay in place good enough without the top straps but do flop around some when walking, which doesn't matter at all. You need pants loose or flexible enough to not bind getting up and down.

[Jack Frederick]

We are up at the old, unsold property cleaning up the old shop. I will take a photo of my cracks and post when we return home. Much obliged for all your suggestions. Myles, you have given me one of those ah-hah moments talking about how level the slab is. I know that garage slabs must be graded, but mine is unique in my experience. it is quartered in 10x10 dimensions. The interior two are level, which is nice, but the door sided two drop almost 3” so a “self-leveling” product may pose a bit of a problem.
My issue today is getting some cedar branches off the top of our well house. This is a tree that PG&E’s tree crew came through and cut the entire road side off, leaving it totally unbalanced. 1/1/22 we had a good storm and our side of the tree dropped some large branches onto the well house. I got those off and taken care of but this recent 54” snow storm with the high winds dropped what you see on the well house. Now, over a year ago I called the utility and they agreed that the tree had to come down and that they would do it, but they managed to delay siting only doing “dangerous” trees at the moment. This is a puzzle to handle as it is two wishbones laying over the peak and of course they are intertwined and the longest branch reaches up into the nearby walnut so it is hung up. I am glad I used that Core-10 on the roof of the well house. It is out by the shop whcih is sided with the Core-10. these large branches barely dented the metal. It is 22 ga. Also glad I sheathed the inside with plywood.