Cement Backer Board

[Mmathis]

Has anyone used or thought of using cement backer board during any phase of pond construction? Just curious since it's waterproof. Have been looking at various suggestions on the forum, and there are instances where you might need/want to have a support structure (or whatever else). People have suggested wood, but that gets into having to cover or protect it from decay.

I'm trying to come up with a way to fill in my walls in a few spots where I want less width, or less slope (in this case, chopping down on the wall isn't an option, 'cause I'm actually trying to make it narrower and this would widen the pond), or want to add a narrow shelf without widening the dig. Don't have the liner, yet, BTW, and trying to keep the liner size down, so want to "renovate" by adding back soil.

Again, just curious and pondering options....

 

[addy1]

I don't see why it would not work

 

[sissy]

It would need support of some sort to keep pressure from pond water from cracking it over time .It may be somewhat waterproof but it is not structurally sound as it is not very thick .As long as it has some kind of support other than itself it may work to point and then fail

 

[addy1]

good points sissy!

 

[Mmathis]

What I was wondering about is using it as a retaining wall so I could back-fill an area with dirt. Then cover with liner. With dirt on one side and water pressure on the other, would that not work? Now, how to secure the backer board in place.....something I'd have to think about.

 

[sissy]

Dirt would not be stable enough i would think since it moves ,when it is wet or dry there is movement .Even when you put backer board under say a kitchen counter top they want it screwed and glued to a plywood backer because alone it is not strong enough if you put something heavy on the counter or do like i do climb on the counter to get something up high on a shelf

 

[Mmathis]

Oh, OK, starting to see it now.

 

[killerbren]

I too have been thinking about doing something like this. The mini ex got a little out of hand and accidentally took out part of my shelves for the gravel bog. I have found that it is very hard to build a vertical wall of dirt once it has been removed. The idea i came up with is to sink pressure treated 2x4's as a "post" and then put pressure treated plywood on the outside, then back fill with dirt or gravel. The posts would be good stability until I could get the pond filled with water. The backer board is a good idea though, I never thought of that.

 

[addy1]

We used 2x4s and landscape timbers (those slightly rounded ones that are 3x5 or so) to make our bog wall, pea gravel on one side, water on the other. It is 28 feet long with part of the ends buried, around 2.5 feet tall.

 

[sissy]

you can also go online and ask the company that makes the backer board .I know when i score backer board and all I have to then is give it a snap to finish the break .Just like you do with dry wall only thing is you have to score it 3 or 4 times, drywall just once .I used concrete block and packed it with dirt and drove rebar down the center for my outside pond walls and then just pulled the liner up over them ,back filled with dirt and then put my outside wall up of retaining wall block .Then just had to cover the top of the liner .

 

[Mmathis]

KILLERBREN, like you, I am having to rebuild vertical walls...

Is it OK to bury wood, even pressure-treated? Won't it decay over time? Or does that matter in the long run? I've noticed that some woods are labled either "suitable" or "not suitable" for below-ground applications (I assume that's more from a structural aspect?).

SISSY, wondering if the concrete blocks & rebar would work for my situation: as KILLER said, due to over zealous use of the excavator [by hubby], am needing to rebuild one side, and a little on the "turtle" side so I can add "rock" shelves. I could dig out what is already there, but that would make the pond wider. I have no problem with "wider," except that it would mean a larger liner. Haven't ordered the liner yet since I'm still tweaking things, but hubby is already suffering from liner-sticker shock, so not sure if he'd go for the idea....

In the smaller spots, like the "turtle" side where it's shallower, and concrete blocks would literally eat away at my allotted space, what about mortaring a little wall in place, then back-filling with dirt before adding the liner. If I can find the bricks with holes, I could re-bar them in place like the concrete blocks only on a smaller scale. I saw where one of the home improvement stores was selling short-cut lengths of rebar.

Dilemma time! HELP

 

[killerbren]

I think in this case the decay wouldnt matter because by the time it decays you would have gravel and dirt behind it from the one side, and water and rock on the other side, both forces pushing towards one another.

 

[addy1]

We covered ours with the liner, not concerned with decay, like killerbren states, gravel on one side, water on the other.

 

[vestaviascott]

I'm considering lining options for my pond build. The base is done and I'm at a point where I can either use rubber liner or waterproofed hardiebacker board. The ends of my pond are constructed from 8 inch core filled concrete blocks. The other sides and floor are hard clay.

Due to the formal rectangular shapes involved, I'm reluctant to go with rubber liner. I've attached a few pics below that show the origami folds needed. Hardibacker board is fairly inexpensive, waterproof (even more so with a paint on membrane like Red Guard) and can be cut to shape. I think I've convinced myself to go with hardibacker board for the upper fountain basin. I'm still undecided about the main pond. I expect that if I go with hardibacker board, I'll still need to pour a 2-4 inch slab for the base.

I'm interested in hearing from anyone who has done this. Thanks!

A few pics:

 

[tbendl]

Liner. Anywhere that has a seal has the possibility of leaking.
Although I don't know about the backer board, it would be the joints that would concern me.