Slate Flagstone?

[AngelaM]

My original plan is to surround the outer edge of my pond with flagstone rocks. I'm running into issues trying to get them to lay correctly on the liner that overhangs outside the pond. Plus some stones are thinner than others so I need to raise them up with a bit of sand or something. My only concern is all this sand going to end up in my pond the first time it rains? I do have a slight angle along the edge of the pond tapering away from it so things wash away from the pond instead of into it. Has anyone used flagstone around the entire edge of their pond? Do you have any helpful tips? Should I trim the liner back some? It overhangs 2 feet in some spots but I thought it would make a good weed barrier. I eventually plan on planting moss between all the flagstones.

 

[addy1]

I did that with my Arizona pond, had flagstone lining the stream and the pond. Used sand and crushed granite to level them. The pond edge was a bit higher, no sand or granite got washed into the pond.

It looks very nice, in az though hard to get anything to grow between the stones.

 

[sissy]

But heavy rains and even lots of snow melt will shift the slate around the pond .The freeze and thaw times will really be the hardest on slate shifting .My slate shifts on a area where I put a bench and I live in VA

 

[AngelaM]

But heavy rains and even lots of snow melt will shift the slate around the pond .The freeze and thaw times will really be the hardest on slate shifting .My slate shifts on a area where I put a bench and I live in VA View attachment 105292

Do you think I should use grout in between to cement them in place? All of my pieces of slate are pretty heavy and big. I wonder if that would keep them from shifting. The smallest pieces are about 10"x10".

 

[Angel]

you can always try 1 year dry fit stack and then if needed grout etc

 

[brokensword]

No, it won't matter; the ground heaves when it freezes. The only way to stop your slate from moving would be to have a footing that is deeper than your frost line. Just let them be and periodically tweak them back into place.

 

[Lisak1]

We laid our flagstone steppers into a sand base in our path to keep them from moving. So far no heaving or shifting at all after two winters. We also built a small flagstone pad for our pond viewing bench and used a sand base plus Powerloc Jointing Sand between the stones to create a more solid surface. That has also held up well for amateur work.

As for the liner, I don't know that I would try to lay the slate over the liner. Are you trying to get the slate to overhang the pond edge slightly? Or just create a path?

 

[sissy]

I live in southside Va and mine shifts in the pic I showed .I used paver sand and the stuff they sell that you wet and it is supposed to stop that .Well not

 

[CometKeith]

Hi Angela. I have always used flagstone to edge my pond. Usually I use larger pieces than 10x10 so they are heavy and don't move. Also kids and animals try to walk on them so the heavier you have them the better. We don't have any small children, but we sold something on Craig's list and their children promptly jumped on the flagstones to get a better look at our fish! I was glad they were in the ground solid. I have always sat the flagstones directly on the liner, If some are thinner or the liner is too low I usually just raise the ground under the liner up by adding dirt or even a brick. If I need to level the flagstone a little on top of the liner I have used pea gravel or small round edge rocks under it which works pretty well. You need to wash pea gravel before you use it because they are pretty dusty. If some pea gravel falls in the pond it won't hurt anything. I use pea gravel in my planting boxes in the pond too.

 

[sissy]

Only bad thing with pea gravel is a fish will sometimes swallow them and they can get stuck and cut off air to the fish .I saw it here one time and it was hard as heck to get the stone out of a fish mouth .My neighbors grandson threw pieces of pea gravel in the pond and the fish thought it was food .I think they spit most out but one fish was acting funny and only thing I could think of was gravel was stuck and it was .Glad she caught it right away and I was home .Not an easy task either .I guess some fish are not very smart .

 

[CometKeith]

Hey Sissy. That sounds a little unusual. I have never thrown in pea gravel and my fish have never ate it. i guess there can be an issue with almost anything but I think pea gravel is very safe. Except when I moved and my construction workers let almost anything go in the pond I generally have at least 98% of my fish make it from year to year. Just yesterday I had to stop one of my guys that was spraying waterproofing solution because it was so windy that some of it was flying towards my pond.

 

[mgmine]

I have flat rocks not flagstone and it lays directly on the liner. Between the stones I planted sedum and it looks nice. Since flagstone is thinner and lighter you might want to keep it from overhanging the edge or at least only overhang a little. I wouldn't use sand or anything else. As far as trying to make them level I would sink the thicker ones instead of raising the thinner ones.

 

[sissy]

I had seen it a couple of times here where gravel got suck in a fish .I guess some fish are not very smart when it comes to gravel .Had one here about 3 weeks ago that called me that had taken in some rescue fish I had given them .There grandson had thrown some pea gravel in the pond and 1 piece got stuck in fish throat and they could not figure out why fish was not eating but his mouth was open .It was a larger piece stuck in fish mouth .Not easy to get out believe as this fish was bigger .It was like when I wrestle my chihuahuas to get their toenails cut .except they are not wet and slippery .

 

[IPA]

I bought some Santa Fe flat stones for the border, just placed on top of liner. My dog gets excited when the fish eat trying to get to them and knocked one into the pond. As it fell to the bottom, straight sides, I could only imagine the hole it was sure to create. Fortunately I dodge that bullet but will be looking for a way to secure them to prevent any more incidents.

 

[AngelaM]

As for the liner, I don't know that I would try to lay the slate over the liner. Are you trying to get the slate to overhang the pond edge slightly? Or just create a path?

Yes I'm trying to let the slate slightly overhang the edge of the pond.