Building a stream, do I need to put anything under the liner?

[csdude55]

I'm finally moving forward with my second pond! Dude's supposed to grade and dig the hole tomorrow

If you don't remember, I currently have a 1000G pond, and I'm building a second 6000G pond about 10' North and 4' lower than the original. I plan to pump the new 6000G pond to a bog filter that will freefall into the original 1000G pond, then have a stream / waterfall from the 1000G to the new 6000G.

I haven't bought the liner yet (I need to make sure of the dimensions when the hole is dug), but I'm planning on buying the super thick Firewall liner. Which is probably overkill, but I have an oak tree nearby and I want to be safe in case a limb falls in to it.

This question is about the stream / waterfall.

I plan to run a piece of that Firestone liner, with river rock along the sides to make the liner into a trench. Then I'll lay in gravel and big flat rock, and cover the edges with more river rock, to make it look natural.

Do I need to put anything underneath the liner? Or is it OK to just lay it straight on the ground?

 

[GBBUDD]

if,you have nothing but sand or clay no roots no bottles glass or rocks sure just liner . but in my book underlayment non woven needle punched geotextile is and insurance policy and to me it goes under and over the liner

 

[csdude55]

I had to google that one. Is that just landscape fabric?

I was thinking about pea gravel, but that gets a tad pricey :-O

 

[GBBUDD]

yes as to fabric BUT it comes in different thicknesses not just the 4 oz garbage at box stores .

pea gravel for the bog ?

 

[csdude55]

I'll be using pea gravel for the bog, yes, but in my post I meant that I'd thought about laying down pea gravel underneath the liner for the stream.

To be honest, I really don't have the money for this project AT ALL! But I'm already halfway through it so the only way out is through. Ya know what I mean?

 

[Lisak1]

Definitely ALWAYS put underlayment under liner... and if I were you, I'd put a second layer on top of it. A stream is an area that might see some foot traffic from humans or critters - protecting the liner from the top is as important as the bottom in that case. Also, the underlayment on top will make the stream less slippery, so less chances of anyone or anything slipping and falling. The fabric will grow a nice layer of algae very quickly and look natural even if the rocks get moved from water flow or feet.

I know you said the budget is tight, but honesty underlayment isn't all that expensive, and since the stream will be narrow you likely won't need more material - just cut the length in two and create a liner sandwich.

 

[csdude55]

In my case, the liner is going underneath large flat rock with the exception of a few feet at the top and bottom. Is there any need to have a top layer of underlayment between the liner and rock?

I don't know what the actual length will be right now, but I'm hoping that 50' will be enough. I'm looking at this one:

Amazon.com

 

[Lisak1]

Well ask yourself this - would you rather do it and NOT need it, or NOT do it and regret the choice later?

 

[GBBUDD]

I'll be using pea gravel for the bog, yes, but in my post I meant that I'd thought about laying down pea gravel underneath the liner for the stream ......... nnoooooo it will constantly move. sand or fabric are the better choices.

To be honest, I really don't have the money for this project AT ALL! But I'm already halfway through it so the only way out is through. Ya know what I mean? old carpet can be used but pray there's no needle pins staples etc

 

[addy1]

My stream is about 85 feet, I used underlayment, and two layers of liner. The deer walk in it all winter snacking on plants. No leaks since built.