Gluing liner to a big rock

[Rimsky]

I'am new here, so Hello everybody.

I would like to use that big rock as an anchorpoint for my - yet to built - waterfall. As you can see on the image there is no way I can put a liner behind it.
The basic idea was having water running down this little valley to the horizontal stone then into the pond. How can I waterproof it.
I tried to glue the liner to the rock with black foam, doesn't work. What about concrete? Will it bond to the rock? But obviously it will not bond to the liner.

Is concrete waterproof, will it crack over the years? (I live in Québec where temperature can go from anything to anywhere)

Any suggestion will be greatly appreciate.

Rimsky

 

[sissy]

most here use pl roofing goop but as long as the liner is far enough under the rock or behind it ,it should not be a big problem as long as water is running down it only really needs a 1 ft overlap to the liner below .I saw a guy here who could not figure out why he was loosing water ,well he put the upper liner under the lower liner instead of over it .Easy fix but amazed me he had been dealing with it for over a year .

 

[Meyer Jordan]

Only absolutely secure method would be the use of termination strips.

 

[Mmathis]

Only absolutely secure method would be the use of termination strips.

What's that?

 

[Meyer Jordan]

What's that?

http://easypropondproducts.com/10-aluminum-termination-bar.html

These are used to secure liner to concrete, wood, rock etc.

 

[RobAmy]

I bit harder to do then Meyer's idea but you could masonry saw cut a track into the stone and install the liner then epoxy it in. That way you do not see metal. A 7 1/2" blade will get in deep enough for a secure fit. That will get you about 1 13/4" deep. A hydraulic cement would work also but the epoxy in the caulking tube size is easier to control.

 

[Big Lou]

Welcome Rimsky.

 

[mgmine]

I had the exact problem. The solution for me was to dig the stream about 6" deep and 12" away from the boulder so that the liner was below the boulder level and away from it. The distance away from the boulder is determined by the size of the rocks that you want to lay on the liner. I removed my rocks so that you can see what I mean. The first picture is the boulder and the second picture is what the stream looks like when the rocks are put in place. Make sure that the stream is deep enough so that you don't have water coming over the edges. If you want a water fall at the boulder point then you will have to dig the area past the drop off point of the water falls deeper. In other words make it like a step,

you can see a small step in the second picture.

 

[Rimsky]

Thank you all.
So many good ideas,
@mgmine: thank you for the pictures and the effort, I like the way the water goes over the rock, very nice. But I want my big to be part of the waterfall.
@biglou: thank you
@RobAmy: never thought of that, great idea if only it is a straight cut. I might be able to do it with 2 cuts...
@Meyer Jordan: so obvious I feel ashamed
@sissy: is this product safe? Thanks

I will keep you posted

Rimsky

 

[sissy]

We all use it to seal one liner to the other and even the ponddigger uses it .Addy uses it also .Most use it to seal bottom drains and weirs on there skimmers and also on there waterfall filters .

 

[sissy]

if you look closely at the tube here you can see pl .on the tube

 

[addy1]

is this product safe? Thanks

I have used it in my ponds for the last xxx years. No issues, no leaks. Just make sure the surface is dry and clean before you use it. Let it cure some before adding water.

 

[sissy]

I have used it ever since addy told me about it and if it is good enough for them and works it is good enough for me .I sealed between the 2 liners on my 1 waterfall last year and it is still holding tight with no problems yet