Questions for the pros - Installing a Paver Patio over Concrete

[Tidybuoy]

Planning out my next project. I have a patio (away from the house) that is currently old concrete with some cracks and mild buckling from tree roots.

I'm wondering if it is ok to re-do with cobble stone type pavers directly over the concrete. I would first do a brick border that is mortared in place and then add about 2" of sand and then pavers.

If I can go this route, should I be drilling into the concrete for drainage? I was hoping to keep this simple and mortaring a border around the patio will be fairly easy as the edges of the concrete are crack free, smooth, and level.

[LWJ]

I'm not a pro. But I did lay a paver patio a while back. The entire key to pavers is having a compact and stable gravel base. I would think if you remediate the root problem so that the concrete is stable, this would be the most ideal possible substrate. You would still put X inches of sand down and run a compactor over the pavers. Not sure about drainage. If you use the acrylic modified sand (or whatever it is) I think the water penetration is minimal. Seeing you are in Fresno, I wouldn't worry about water!

[Tidybuoy]

Thanks. I believe the root problem occurred many, many years ago. I've lived here 21 years and the patio hasn't changed. But, the house is 70 years old so I have no idea what happened to the concrete - it's mostly big cracks over the surface. I think with 2-3" of sand, the pavers will be stable. I think the border of brick will be 2 bricks high so I figure 1 bricks worth of sand.

At the moment, I'm just planning it out. The only thing good about Covid is that I'm getting lots of home improvement projects done.

[Nate2046]

Rank amateur here but I did what you’re describing this spring on this weird peninsula of concrete in our backyard. Haven’t seen any issues so far. I used plastic paver edging around the perimeter and drilled weep holes every foot or so. I figured all the cracks in the concrete would also allow some drainage. Used landscaping fabric to keep the sand from washing out.

This is what we inherited.








Result

[LWJ]

^^^that is killer!!!!!

[Tidybuoy]

Wow! You did a good job!

[Nostril Cheese]

Agreed, great job. Thank you for the info. Need to do something similar..

[p911dad]

I'm no pro for sure, but about 30 years ago I put down pavers (look like thick bricks) over an old 30' X 12' patio adjacent to the house foundation (house is a walkout ranch, 2 levels) With the help of a contractor friend we leveled the patio with a concrete leveler, laid down the pavers and brushed in a fine sand to lock the blocks together. We used the edging material from the provider and backfilled with good topsoil to hold the pavers in place and to meet the lawn so there was no tripping hazard. It is still there and has not shifted. It was well worth the effort as it saved ripping up the old concrete. It still looks great.
This brought back a funny memory of carrying the pavers down to the lower level. The truck dropped the pallets of pavers on the edge of the drive and it was up to me to get them down the hill to the patio worksite. It was a major pain carrying the pavers down the hill, so my good neighbor volunteered his lawn tractor and wagon to carry the loads down the hill. Loaded the trailer and off he went down the hill. But - the grass was wet with dew, he lost control of the load and he sailed down the hill with brakes locked right into and through the back neighbor's hedge. Then we carried the pavers back up the hill..

[Tidybuoy]

Sounds like when I moved my upright piano to my new house. It was raining so we covered it really good but halfway down the ramp from the truck, we lost our grip on the ramp and the piano took off - straight towards my front door. It miraculously stopped 1" from the front door.

[look 171]

Depending on the thickness of the concrete but I would just lay down sand and pavers. Some type of geo-grid can be used to keep everything together. For filling the gaps, a Polymer for joints should be used. they dry with a bit of water and stick together unlike regular play sand. I am no expert on this subject.

[FPB111]

Don’t use sand, use QP and stone dust/fines that you can compact, sand is always on the move.

Quarry Process.
Quarry Process Stone, Northern NJ, Sussex County

[stevej37]

Never used them myself, but have heard great things about these....
https://www.menards.com/main/building-materials/landscaping-materials/landscape-rock/brock-paverbase-reg-panels/1891134/p-1546587207114-c-5784.htm?tid=5150738276418190348&ipos=2