Using bedrock and concrete as a pond...?

[YKdave]

Hi guys, new to the forum and looking for a little advice...

As you can see in my other thread (https://www.gardenpondforum.com/topic/11995-some-newbie-looking-for-some-input/?p=175051) im looking at expanding the current little pond/stream into a much larger pond.

Due to the geography in my yard, i am very limited on space, so i would like to use the natural bedrock as the bottom and one side of the pond. then possibly use concrete walls for the remainder. Aside from what i think would be an amazing look with the natural rock as the bottom/side of the pond, it maximizes my limited pond size.

My biggest concern is sealing the concrete walls to the bedrock and sealing any fractures in the bedrock and of course the toll that frost would have on such a setup.

I am thinking that i would likely have to 'pin' the walls to the bedrock bottom to keep the wall from moving, and i would assume i am looking at doing yearly fracture repairs...?

The attached pic shows the old setup ripped out and my desired outline for the retaining wall along the lawn. the line is appx where i expect the water line at, the wall will be higher. and an awesome little diagram of what i have in mind as far as the concrete wall.

Any ideas as to how well this may work, and for sealing the concrete wall to the bedrock?

 

[addy1]

That will look amazing.
I know they sell pond sealant, black rubber sort of stuff you can paint on, spray on that might seal it. I have read of people using it to seal concrete ponds.

 

[YKdave]

An idea what the 'bottom' of the pond is going to hopefully look like...

This is of course the shallow side being the closest to the bedrock outcrop. As I go farther left it drops sharply

 

[DrCase]

Beutifull rock
I don't see you ever getting it water tight

 

[YKdave]

Well I'm not so concerned about the rock color, I was hoping that whacking a few pails of epoxy based sealer on it would maybe seal it up? I don't think a gray sealer would look too bad, and of course I would mortar all of the cracks beforehand.

Personally I just don't like the liners because a black piece of rubber looks like crap to me (not to mention they arent even available locally) Even if I have to mortar the big cracks and paint a sealer on the rocks, I think it will still look good due to the natural texture and shapes that are there...

But, if theirs really no possible way to do this, I could resort to using a liner, but its definitely my last option.

I've made a little more progress on the digging, sun has gone behind the trees and the bugs are getting brutal. I'm done for the night!

 

[HTH]

Once a pond has aged you can't tell if what you see is rubber or rock. It is all covered with algae anyway.

A somewhat smooth bottom is easier to maintain..

 

[YKdave]

Regardless, it's still my last resort. As I had mentioned in the other thread, I plan on making a waterfall off of the bedrock also. That part I want to leave bare and natural as much as possible, and of course it would just run down the rock face into the pond. Everything below the pond water level would be sealed up as best as I can achieve

I'm thinking that would be pretty much impossible to achieve if the pond used a liner...?

 

[HTH]

I'm thinking that would be pretty much impossible to achieve if the pond used a liner...?

Are you thinking this is because you can't bind a liner to a rock. I am not sure if that is true or not. There is a lot of interesting stuff out there. If the rock is not soft or powdery it may be possible. You might want to build a concrete water path over the existing rocks using expanded metal reinforcement. I have seen a youtube where they did the entire pond that way. It would give you a water tight path for the water without trying to hide a liner.

Also need to warn you that water leaks in water falls is one of the major complaints on this and other forums.

And this advice is worth every cent you paid for it.

 

[YKdave]

Yes that's my thoughts, trying to bond the liner to the rock so that the water coming down from the waterfall doesn't end up going under the liner instead of into the pond

And of course this is a little different than most people's waterfalls. If I can get away without using a liner, any 'stray' water from the waterfall would just make its way down into the pond. Theirs literally nowhere else for it to go except for back into the pond. I think if anything I'm going to lose a lot of water from evaporation with the water splashing down and running back into the pond over such a wide flat rock

I suppose using a liner, and making a concrete path for the waterfall water to run back into the pond would work. But then again we have the issue of any stray water easily going outside of the pond system, and the concrete not being as appealing to the eye as the natural rock

As always, you get what you pay for, same goes for Advice lol. Just hoping someone has tried something similar, and I can learn from their mistakes!

 

[YKdave]

Looking around I see Dow Corning makes a spray foam for ponds . It's black and fish safe....

I'll be pressure washing the bedrock before going too far into things, ill be able to get a better look at the couple of cracks and I think that may be a good solution for sealing the larger cracks/fractures.

It definitely sounds better than trying to seal it with mortar...

 

[addy1]

This build is going to be real interesting to follow. Love your rock, just love it, makes you think of new ways to build a pond and stream

 

[bean6924]

I would not use the black foam. It's not water tight, and will only last a short amount of time. I think your epoxy will much more effective.

You could also use shotcrete along the edges of the falls instead of the liner, and build a little "test" area around the bedrock ( build sides up a foot or two) after applying your epoxy to see if it's water tight. There are also epoxies that you can add to concrete to help with water tightness. It would seem to me that this would stick to bedrock much better than any effort to get liner to stick.

check out this stuff -

http://www.pebblerockflooring.com/

really cool idea though. could be incredibly beautiful.

 

[YKdave]

I was thinking more or less using the foam to fill in any major voids, jus tto give it a 'bottom' before capping with shotcrete/mortar and sealing everything with epoxy coat or whatever i go with. Just sounds easier than pumping shotcrete/mortar into the rock until it starts coming out in the neighbors yard LOL

I love the look of that pebble rock flooring, unfortunately where i live i am very limited on my selection of products and that is definitely not something i can get without a logistical nightmare! (same goes for a pool liner if i have to go that route)

Expoxy based concrete floor paint/coating is something i can easily go downtown and fetch, that is likely going to be the route i go when its time to seal this.

 

[bean6924]

I was thinking more or less using the foam to fill in any major voids, jus tto give it a 'bottom' before capping with shotcrete/mortar and sealing everything with epoxy coat or whatever i go with. Just sounds easier than pumping shotcrete/mortar into the rock until it starts coming out in the neighbors yard LOL

I love the look of that pebble rock flooring, unfortunately where i live i am very limited on my selection of products and that is definitely not something i can get without a logistical nightmare! (same goes for a pool liner if i have to go that route)

Expoxy based concrete floor paint/coating is something i can easily go downtown and fetch, that is likely going to be the route i go when its time to seal this.

That makes sense.

 

[HTH]

Keep in mind that saturated rock will spault or split with freeze thaw cycles. Any rock that gets wet directly or indirectly need to be sealed if it will freeze.

I had a formal pond in a greenhouse enclosure that had a freeze thaw cycle frequent over the winter. It reduced the concrete pavers on one side to rubble.