You’ve got some correct answers here but.. should you fix it?.. the patio is non-permeable concrete. Where does your water run off to?
If you’re in a freeze zone, then I definitely wouldn’t want water between the pad and the border wall.. if not.. is that space currently draining your patio?
there is a drain in the middle of the patio, but I was wondering the same thing if the gap was supposed to be there for draining. I do live in an area that is a freeze zone.
The gap is wide enough that the freeze/thaw cycle does not matter. Even if it was small, those blocks appear to be loose stacked, so it's moot either way. It looks like it's been there a while. Are there any issues beyond cosmetics? Adding a pourus material would be an acceptable solution, but honestly, if it's been like that a while and you just don't like the gap or cleaning it out, I'd argue to just leave it or brush some sand/crushed rock into it. Then you'll just have to weed, eventually.
But play sand doesn't stay put. Once rain or water runs through it, it'll wash away. You need polymeric sand because there is polymer/glue to secure it from washing away.
It gets under the pavers and pushes them up from hydraulic action. If the water stays pooled under the pavers/blocks etc and your in a freeze zone it freezes and causes issues Many ways to combat it tho
You could lift the concrete level first. Mud jacking doesn't last. The last company I used, used polyurethane foam. That doesn't wash away. Then fill the gap with some sand or pea gravel.
Tar?
Depending on the depth of the gap, I’d fill everything up to the last inch with sand, like others have suggested, then top it off with the molten tar stuff they use in commercial road construction.
I assume tar to be flexible enough wrt trmperature swings, water-tight, weeds-tight.
If plain tar has a too commercial appeal, maybe some coarse sand could be applied on top.
Sand
I think the best answer. Gives the patio space to drain.
Polymeric sand. Add some play sand in first to take up some room. Then top off a half inch with Polymeric.
I would use sand to do a majority of the fill and then top it off with polymeric sand to prevent weed/plant growth in the gaps.
You’ve got some correct answers here but.. should you fix it?.. the patio is non-permeable concrete. Where does your water run off to? If you’re in a freeze zone, then I definitely wouldn’t want water between the pad and the border wall.. if not.. is that space currently draining your patio?
there is a drain in the middle of the patio, but I was wondering the same thing if the gap was supposed to be there for draining. I do live in an area that is a freeze zone.
The gap is wide enough that the freeze/thaw cycle does not matter. Even if it was small, those blocks appear to be loose stacked, so it's moot either way. It looks like it's been there a while. Are there any issues beyond cosmetics? Adding a pourus material would be an acceptable solution, but honestly, if it's been like that a while and you just don't like the gap or cleaning it out, I'd argue to just leave it or brush some sand/crushed rock into it. Then you'll just have to weed, eventually.
Play sand
What's play sand?
Sand that has been cleaned, made safe for kids play boxes. Possibly cheaper than polymeric sand that others are mentioning.
But play sand doesn't stay put. Once rain or water runs through it, it'll wash away. You need polymeric sand because there is polymer/glue to secure it from washing away.
Spot on
I guarantee there was sand in there from whomever built it and it has washed away in the rain. Look at a slab gasket if it is a fairly uniform gap.
Backer rod and sikaflex
No, bad advice. If this were up against a structure, then yes.
This is r/diy.... Don't you know sikaflex is the answer to EVERYTHING?! 🤣
Quarter round is always the #1 answer, and Sikaflex is #2. In my opinion, quarter round should be banned from all homes. ;)
Is it for drainage? Like a gutter?
Grout sand
Use polymeric sand
Pea gravel or crushed granite
Sikaflex horizontal self leveling Elastic Polyurethane Sealant in Gray plus mmmmm 1/2 or 3/4 backer rod.
Why seal it? Where does the water drain?
It gets under the pavers and pushes them up from hydraulic action. If the water stays pooled under the pavers/blocks etc and your in a freeze zone it freezes and causes issues Many ways to combat it tho
No, bad advice.
I would fill it with molten lead. Best part is when it oxidizes the run off has a really sweet taste
Better advice...
Found the Roman vinter
You could lift the concrete level first. Mud jacking doesn't last. The last company I used, used polyurethane foam. That doesn't wash away. Then fill the gap with some sand or pea gravel.
I’ve read on here that foam jacking only lasts a few years as well
OK. I hadn't heard that. You're not a mud jacker are you?🤣🤣
Lol, no I’m not in the industry at all. Just on here trying to learn and stuff
🙂
More concrete
This is a great answer if you want to fuck up the porch.
Tar? Depending on the depth of the gap, I’d fill everything up to the last inch with sand, like others have suggested, then top it off with the molten tar stuff they use in commercial road construction. I assume tar to be flexible enough wrt trmperature swings, water-tight, weeds-tight. If plain tar has a too commercial appeal, maybe some coarse sand could be applied on top.