Sealing a joint between two concrete slabs?
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Sealing a joint between two concrete slabs?
I don't know much about concrete, so need some advice. There are two concrete slabs that come together right under a small gate going to my back yard. The slabs have pulled apart a bit through time. It looks like former homeowners filled the cracks with a black caulk-like material that itself has now deteriorated and is gone from much of the crack. Also, there is a chip in the edge of one of the concrete slabs, making a gap that a small animal could get through. Today I noticed a lot of sand dug up along a couple of feet of the edge of the crack between the two slabs. I'm sure that an animal (probably chipmunk) has gotten in there. The chipped area would be big enough.
My question is, what would be best to use for sealing this joint? From other posts here, I understand that the area needs to be thoroughly cleaned first, etc. But I haven't figured out what product to use. The gap between the slabs is at least a half inch wide, and wider right where there is that chip in the concrete. Any help would be appreciated!
My question is, what would be best to use for sealing this joint? From other posts here, I understand that the area needs to be thoroughly cleaned first, etc. But I haven't figured out what product to use. The gap between the slabs is at least a half inch wide, and wider right where there is that chip in the concrete. Any help would be appreciated!

#2
i would use a piece of small dia pipe insulation down in the crack and then a good caulk to cover the top. the concrete will expand when it is heated by the sun so the gap will change depending on the weather.
murphy was an optimist
murphy was an optimist
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Thank you!
Thank you for the advice! I wouldn't have thought of the pipe insulation. I'm not extremely handy, but think I could do this. I'll ask at the store for advice on what caulk to get.

#4
Sealing a joint between two concrete slabs?
If the pipe insulation is too large you can easily get backer rod (different diameters of flexible foam rod) at the big boxes. - Usually somewhere around the caulking materials.
What ever you use force it donw into the joint and hthen apply caulk, forcing it down to use the rod suoort the caulk and make it adhere to both sides of the joint.
Dick
What ever you use force it donw into the joint and hthen apply caulk, forcing it down to use the rod suoort the caulk and make it adhere to both sides of the joint.
Dick
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Thanks! I just got back from the store, and they recommended I get the backer rod, so I did. I noticed the crack between my two slabs varies in width. I got some that will fit into the largest width if I shove it in there. They told me not to let the rod stick up over the edges of the concrete, so I'll find something to jam it in there with.