Pond liner cut too low!

[AndrewCL]

Hi folks
I dug out for a pond. I laid the liner. I used pressure treated timber to create a frame (the corners where wood meets wood are not sealed… the wood is there as a frame only to hold the EPDM liner. I then poured ready mix concrete (probably not itself waterproof) between the liner and the wood. However I didn’t come up far enough in one corner with that concrete. When the concrete set, I cut the liner too low (as I stupidly followed the concrete level when I cut.
I am kicking myself!
I attach a few photos.
The water level has fallen 6 inches. Roughly the same as the lowest level of my cut liner.
The simplest solution seems to be to mix waterproof concrete and pour it in the corner inside the liner where’s there’s a gap and an inch outside the liner and for the missing few inches above the liner.Effectively I’d like to think this would restore my waterproofing up to the rim of the pond.
I’ve thought about adhering a 6 inch strip back on to the liner where I’d cut it and then repour concrete inside just to hold it. I’m sceptical as to whether the adhesive and strip would offer a solution.
I’ve attached a few photos.
Please! Would anyone offer a steer?

 

[GBBUDD]

I Hate to add to your woes but you said you were using pressure treated lumber and your lumber is sitting in the water . Not the best scenario. it is not that hard to seam epdm here is a link https://www.gardenpondforum.com/threads/seaming-epdm-liner.26807/

 

[AndrewCL]

That’s brilliant. The videos are really helpful. I’ve been lucky in that I have enough rubber left to add a double layer in part to the pond (and an overlap in to the shoddiest area. There will be a seam so I’ll add sealant to join the two. Thanks again

 

[combatwombat]

If you want it to last long-term, I'd really recommend doing a proper EPDM seam w/ primer and butyl seam tape.

 

[j.w]

@AndrewCL

 

[AndrewCL]

If you want it to last long-term, I'd really recommend doing a proper EPDM seam w/ primer and butyl seam tape.

That’s brilliant. Thanks a million for the response

 

[addy1]

The other thing some have done is pull the short liner away from the wall back fill with dirt and it makes it "longer" Add a neat rock on that little goof and it will look like you meant it to be.

 

[AndrewCL]

The other thing some have done is pull the short liner away from the wall back fill with dirt and it makes it "longer" Add a neat rock on that little goof and it will look like you meant it to be.

 

[AndrewCL]

Thank you so much for the reply.
For the moment I have filled in the shoddy corner with “waterproof” concrete. I’m waiting for that to set before filling with water and monitoring. (I’ve also added a partial layer of EDPM. However that’s sitting on the existing layer and I simply can’t seam it properly because of the amount of creases and contours. (So it’s effectively useless I’d imagine cos water will get under it and go to the corner to test my concrete!).

Yes that’s a good idea. I’d be coming in in width of pond by say 6 inches to get back up 3 inches in height. I’d be losing most of the first level “step down” on that side. That wouldn’t be the worst thing in the world.

To be frank if I had my time all over again I’d do it very differently. I’d keep it simple. Using concrete between the liner and the one foot timber was untidy and mislead me as to where to cut.
Doing it all over again I’d simply have used 3 inch wood with 2 inch stakes to hold it. I didn’t because soil v sandy. However I could simply have poured small neat concrete bases for each post. You live and you learn!

Thank you again!

 

[GBBUDD]

SEAM alternative and much easier to work with wrinkles is to use a quality caulking pl s30 is one such but takes 8 hours to set

 

[addy1]

SEAM alternative and much easier to work with wrinkles is to use a quality caulking pl s30 is one such but takes 8 hours to set

Pl works great, I have used it to stop leaks, and fix a fold issue.
Main thing is make sure the liner is dry, rough it up a tiny bit with sand paper, goop the heck out of it, push the liner together full of the goop in every crease, fold, and let it dry. I have let it dry I have also let it get wet quicker, both have worked, but letting it dry is safest.

 

[AndrewCL]

SEAM alternative and much easier to work with wrinkles is to use a quality caulking pl s30 is one such but takes 8 hours to set

Thank you!

 

[AndrewCL]

Pl works great, I have used it to stop leaks, and fix a fold issue.
Main thing is make sure the liner is dry, rough it up a tiny bit with sand paper, goop the heck out of it, push the liner together full of the goop in every crease, fold, and let it dry. I have let it dry I have also let it get wet quicker, both have worked, but letting it dry is safest.

Thank you!

Thank you!

for

 

[AndrewCL]

Thank you!

for

Forgive the question but is this geocel sealant the type of stuff that will do the job? Every time I push down a bump in the extra liner I get another one. With the amount of bumps (see photo) I’ll be using a lot!

 

[GBBUDD]

first of all the overlap is backwards lower should be under the upper and then start sealing. and if you look at the waves if you pulled the liner down and toward the right the liner will sit pretty close to what is ideal to seam. like i showed on the blog getting a piece of pine under the seam makes it a lot easier even if its a battle to get it in or out

not familiar with that product but geocell also makes this which i have used many times including in my pond great stuff. https://www.familyhardware.com/prod...4002&msclkid=06ae758ab5851fb1bff811c464980ecc