Should I caulk the grooves between the concrete slabs in my driveway?

Question

There is evidence that black tar-like stuff was once there. Now there are deep cracks filled with sand. I would think it would be beneficial and can't think of any harm it could do. But I don't understand why I don't see this being done on brand new driveways. I live in Michigan and want to protect the cement from freeze/thaw damage.

Answer 1

It would protect it from water damage and such, as well as preventing vegetation to grow out, I say go for it.

Answer 2

I recommend filling the joints with a bituminous type caulk (or other suitable material recommended for this purpose).

The reason for this is to avoid moisture being in the void, or under the slab, during a hard freeze. That could cause heaving or "shoulder" damage to your concrete. This a very real possibility in Michigan.

Check with builders in your area. They will confirm my advise.

Answer 3

i would get the sand out of there and caulk it, if it were mine...sand will hold water and freeze...a bare gap will let water through and if the slab was installed correctly there will be stone under the slab to take the water away...but a bare gap will collect dirt and sand again, so caulk it after you clean it out ...

Answer 4

no do not caulk cause the cracks give the water a place to go and when it freezes it gives expansion room for ice to minimize shifting and deteriation of surface

Answer 5

I would leave it alone. Those are expansion joints and the black tar stuff you saw was a sealanct. However, by now, it's original intention has been done and I doubt that there is any moisture getting between the pours. If it makes you feel better, you won't hurt anything by re-doing it, but don't feel as if it is necessary

Answer 6

The cracks are there to protect your driveway. It will expand and contract with the changing temp and if it has no where to go it could crack. You may want to treat it with weed killer if grass or weeds starts growing in the sand but I wouldn't bother with the caulk.

Answer 7

those are expansion joints, the concrete is supposed to expand and contract at these joints. you can get the same tar they used to begin with at Lowe's or home depot. it comes in a caulking tube easiest way is to get a complete vegetation killer and spray it in the crack though.

Answer 8

I'd leave it, concrete needs to expand...just throw some vegetation killer in the cracks to keep out the weeds