Existing pond remodel

[Pond-girl]

Hello and neeed help! I have a 10’x20’ existing concrete pond w/waterfall. I had Koi years ago but live in Las Vegas and never could keep it clean (it was 4’ deep) I’ve filled with dirt. Then added a thick layer of play sand as underpayment to my EPDM liner.
I don’t want a full pond....just a pool of water w/ waterfall running and will fill in edges with rocks.
My question is: how do I successfully attach the liner to the concrete at the waterfall section? (See photo w/ red line) or do I need to add or build “out” to create a ledge and tuck liner behind? Seems impossible to ensure a solid adhesion of liner to concrete , because water will be flowing over that 24/7.
Any help is appreciated!
PS not for fish and ignore tarp on ground, that so dog won’t dig up my sand!

 

[Stephen Noble]

Welcome to the forum! I am having difficulty understanding. I can't see your EDPM. Is it covered with rocks? The waterfall looks like it has a gap just above the red line. Are you asking how to seal that gap? Is that small white tube (bottom of image) the uptake for the waterfall? Could you please make an image showing the entire pond area?

 

[Lisak1]

Welcome @Pond-girl !

@Stephen Noble - The red line is where she imagines attaching the EPDM. She doesn't currently have liner in the pond but is adding it over an existing cement pond.

@Pond-girl I think it's going to be next to impossible - as you suspected- to attach liner to concrete. If you can find a way to add a ledge, that might work. But could you possibly reconstruct the waterfall completely? You really need that liner all the way up to where the water starts to flow. Starting the liner partway down the waterfall is a recipe for disaster - if that water starts to seep behind your liner, you'll have a floating liner in a matter of hours. And seep it will! If you could add a biofalls or even a spillway, it would make for a better outcome.

 

[j.w]

@Pond-girl

 

[Pond-girl]

Welcome @Pond-girl !

@Stephen Noble - The red line is where she imagines attaching the EPDM. She doesn't currently have liner in the pond but is adding it over an existing cement pond.

@Pond-girl I think it's going to be next to impossible - as you suspected- to attach liner to concrete. If you can find a way to add a ledge, that might work. But could you possibly reconstruct the waterfall completely? You really need that liner all the way up to where the water starts to flow. Starting the liner partway down the waterfall is a recipe for disaster - if that water starts to seep behind your liner, you'll have a floating liner in a matter of hours. And seep it will! If you could add a biofalls or even a spillway, it would make for a better outcome.

Yep that is pretty much what I saw happening . Or like u said run liner to “top side “ of waterfall but prolly would end up looking like a shiny turd when all done. I was hoping to find an adhesive for the ‘liner to cement’ side and then another product that I could layer overtop the newly adhered liner and concrete...if that makes any sense. OR Plan F....Ditch using waterfall and just install a recirc type pump so water isn’t stagnant? If so, any suggestion on what to search for or name for this function/etc?

 

[Sparky]

This might sound nuts but what if one were to lay the liner up to base of waterfall and some creative concrete mason work right over the top of it with enough mass to pin the liner down?

 

[Pond-girl]

Sparky! This pond remodel or salvage requires some nuts type thinking! I thought about that idea too. I figured concrete would be too pourous and unless framed from below, wouldn’t “stand up”....I did see a product called black waterfall foam. Whereby, I could adhere the liner to face of Concrete...(pray). Next step, place rocks from bottom of pond (on top of liner ) to just above the liner edge using the black waterfall foam ? Now that I think about it, ur concrete idea or my rock idea are basically doing the same thing.

 

[Sparky]

Sparky! This pond remodel or salvage requires some nuts type thinking! I thought about that idea too.

The foam is not structural IMO. I use it but not for adherence. The concrete “cap” would need to start up a ways almost like a thick veneer and eventually to at least 3-4” thickness where it ends on top of the liner. The mix at the bottom would have to contour the bottom snugly holding the liner in place. Rocks on top to suit. This would be a quickset deal. It’s nuts..... but..... might work

 

[sissy]

addy use PL roofing goop

 

[addy1]

addy use PL roofing goop

The stuff works great and holds great, but all must be dry for it to adhere. I have used it a lot, still holding tight.

 

[Pond-girl]

The stuff works great and holds great, but all must be dry for it to adhere. I have used it a lot, still holding tight.

....thank u! So I could lather the PL roofing goop over my existing concrete and edge of liner?

 

[addy1]

I would make sure it is clean, scrub etc, wash let it dry well. Get the goop, puts lots on, push the liner into it. Once it dries some, put more goop on the edge of the liner, making sure the edge of the liner is totally covered with goop.

 

[Pond-girl]

I would make sure it is clean, scrub etc, wash let it dry well. Get the goop, puts lots on, push the liner into it. Once it dries some, put more goop on the edge of the liner, making sure the edge of the liner is totally covered with goop.

Thank u very much! I will update my post when I’m done! Appreciate ur help!

 

[Sparky]

Addy, the goop master! Officially now in my pond tool box.

 

[addy1]

It has been sealing my output pipes from two small ponds into the big pond for over 6 years. Survives winter summer critters me