It looks like the previous homeowners cut the concrete due to settling issues(?) and now we've got some pretty wide cracks or gaps in the patio. Are these a good candidate for filler rope and caulk, or is there a better approach?

From the apparent width based on the timber stair, it would be a good candidate for caulk. I’d specify a polyurethane backer rod rather than rope. Thickness of caulk at centerline of joint/backer rod should be half of the joint thickness. Dow Corning 888 is a premium silicon-based joint sealant for adhering to concrete, but Home Depot has some good choices at a fraction of the cost.

Backer rod with Sika Flex on top will work well.

I could be wrong, but those look like expansion joints. I would be hesitant to fill them.

First try to figure out why they cut them that way. It could've possibly been for drainage or could've been for expansion. I wouldn't use the caulk products mentioned above, I think the joint is too wide and normal caulk will just fall in as it's curing and you'd use a ton of it to fill that size gap.

Crack filler, that you put in the crack and heat would be a good choice. But I think West System Six10 would be your best choice and easy to use (it's in a tube like caulk and you use a caulking gun to apply it. It is an amazing product and just for that kind of purpose. Can also be tooled with a wet popsicle stick to give you a very nice bead and will last virtually the life of the concrete where the caulking won't and the caulking will also get moldy.

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quote:

t looks like the previous homeowners cut the concrete due to settling issues(?) and now we've got some pretty wide cracks or gaps in the patio. Are these a good candidate for filler rope and caulk, or is there a better approach?

^^^^
I would strongly suggest getting an engineer's opinion on the issue. Diagnosis before treatment is usually best.

quote:

Originally posted by ZSMICHAEL:
I would strongly suggest getting an engineer's opinion on the issue.

Ground-penetrating radar is my suggestion. Really get a good look.

Or fill a couple with a slightly-recessed weak mix of concrete. ⅓ mortar mix and ⅔ sand in the color of your choice. Mix it dry, like snowball dry. See what happens over the winter before doing all of it.

quote:

Backer rod with Sika Flex on top will work well.

This if you are going to caulk the joints. I will be doing this to my driveway at some point this year.

Have you seen movement in the slabs since you occupied the house? if its been a while and have had no movement, i would not worry.

Cracking concrete is one of those certainties in life and the best way to control it is to cut joints like is shown. Now, if one corner of the slab is depressing or if you see differential settlement, then hire someone to look at the slab. Still caulk the joints though.

Well, I know there's settlement issues - it looks like portions of the front walk and RV pad have been filled (is that the right term?). There's little filled holes in several places, and some areas sound hollow when walking on.

I think I would add some sand to fill the joints from time to time. Don't want to loose any of your gold or silver coins.

I would not use caulk. I would look for that landscape sand that deters weeds from growing in the cracks but will allow water to drain.

any Sitka brand self leveling or other type stika caulk. Call them theyll advise you. I used their self leveling on sime wide joints in concrete, durable great stuff. Backer rod for you.
ask them for advice on backer material, not all are created equal.

Those are control joints. Concrete is GOING to crack. You cut the partial depth of the concrete which encourages the cracks to occur in that location.

quote:

Originally posted by 4x5:
There's little filled holes in several places, and some areas sound hollow when walking on.

I've never seen this, but heard about it here. A tech can drill holes and pump in something to lift a dropping slab. Then patch the penetrations. Hence the hollow sound, as perhaps once lifted, the sub-area may have voids.

I don't know much about concrete, but I know that cracks in anything are never straight, even and perfectly intersecting. The gaps do look pretty wide, however. I'd find and hire an expert to see what is going on.

Home Depot sells sanded caulk that looks like grout when it hardens. I’ve used it in similar applications with good results, although not on gaps that wide.

Yep. They can be filled. Sika, quickrete, Dap all have self leveling products that will bridge wide cracks. I’ve been in the process of filling mine

By the looks of yours a backing rod will help in not using a great number of tubes filling the entire depth

The products can be found by the concrete in both Lowe’s and Home Depot. Not the Paint Depts

quote:

Originally posted by mark60:
Backer rod with Sika Flex on top will work well.

My thoughts as well.

Those look an awful lot like expansion joints. The corners are too perfect

I wouldn’t fill them but then again I’m just a dumbshit engineer

quote:

Originally posted by snwghst:
Yep. They can be filled. Sika, quickrete, Dap all have self leveling products that will bridge wide cracks. I’ve been in the process of filling mine

By the looks of yours a backing rod will help in not using a great number of tubes filling the entire depth

The products can be found by the concrete in both Lowe’s and Home Depot. Not the Paint Depts

If your backer rod doesn't reach the bottom of the chasms, I might pre-fill them with fine builing sand or poymeric sand before the backer rod, followed by the products suggested by snwghst above.

I can't remember if you said the slabs were sliding away from each other. If they are I don't know how to handle that.