Bio-filter & EPDM & Masonry

[Telkwa]

We bought enough EPDM to create a bio-filter & small waterfall from the same sheet that's forming the pond. Instead of using a plastic shell (drum or stock tank or etc.) for the bf I'm thinking about building an enclosure from wood or maybe even concrete, then mortaring rock to the structure.

Does anyone have any suggestions for mortaring over EPDM on a vertical surface? Can it even be done? The only thing I can think of is to (carefully) place some stout wire mesh over the EPDM, then start mortaring just like any vertical wall. But I've never done masonry on any vertical surface, much less over a slippery, wiggly material like EPDM, so if anyone has some experience in this I'd love to hear it.

Another question – if you were to build a bio-filter with EPDM, how would you get a bottom drain out from underneath? Is it horribly difficult to place a bottom drain that will work with EPDM into a small cement slab? Or maybe use a piece of really stout marine plywood, cribbed up underneath everywhere except where the drain is installed?

 

[Telkwa]

We bought enough EPDM to create a bio-filter & small waterfall from the same sheet that's forming the pond. Instead of using a plastic shell (drum or stock tank or etc.) for the bf I'm thinking about building an enclosure from wood or maybe even concrete, then mortaring rock to the structure.

Does anyone have any suggestions for mortaring over EPDM on a vertical surface? Can it even be done? The only thing I can think of is to (carefully) place some stout wire mesh over the EPDM, then start mortaring just like any vertical wall. But I've never done masonry on any vertical surface, much less over a slippery, wiggly material like EPDM, so if anyone has some experience in this I'd love to hear it.

Another question – if you were to build a bio-filter with EPDM, how would you get a bottom drain out from underneath? Is it horribly difficult to place a bottom drain that will work with EPDM into a small cement slab? Or maybe use a piece of really stout marine plywood, cribbed up underneath everywhere except where the drain is installed?

 

[DrCase]

I wanted to bump this back up

Are you wanting to rock the walls inside of your pond ?

 

[DrCase]

I wanted to bump this back up

Are you wanting to rock the walls inside of your pond ?

 

[Telkwa]

Hi, Doc -
The pond's already done. This would be for a bio-filter, so a much smaller structure. Probably about the size of a bathtub.

You bring up a good question. The EPDM wouldn't be in the way on the outside of the structure, only the inside and top edge. And I only need to hide the top few inches of EPDM inside, until we get into biomedia or water or whatever.

Perhaps I should think instead about just camouflaging the EPDM on the inside by stacking some rock loosely, or using plants, or a wood cap with a shoulder that drapes down along the inside. Maybe I could build a small ledge inside the structure to help stack a short rock wall inside. Maybe waterfall foam would work with a ledge inside?

From what I can see on the internet, you really need to attach a stone veneer securely. Either you can veneer to clean concrete, or use a stout wire mesh and ties attached to the wall.

BTW, I talked to a guy who sells rock for a living, (Mutual Materials in Olympia WA) and he said that the "cultured stone", which would be easier to veneer, looks fine by itself but looks wrong when you have real rock right near by. Which we will.

The "box" for the biofilter will probably only be about 2 to 2.5 feet high. I think I want to build it at a height that would be comfortable to sit on the edge. That should make it a little easier - I get the impression that the technical challenges increase as the wall goes higher.

 

[Telkwa]

Hi, Doc -
The pond's already done. This would be for a bio-filter, so a much smaller structure. Probably about the size of a bathtub.

You bring up a good question. The EPDM wouldn't be in the way on the outside of the structure, only the inside and top edge. And I only need to hide the top few inches of EPDM inside, until we get into biomedia or water or whatever.

Perhaps I should think instead about just camouflaging the EPDM on the inside by stacking some rock loosely, or using plants, or a wood cap with a shoulder that drapes down along the inside. Maybe I could build a small ledge inside the structure to help stack a short rock wall inside. Maybe waterfall foam would work with a ledge inside?

From what I can see on the internet, you really need to attach a stone veneer securely. Either you can veneer to clean concrete, or use a stout wire mesh and ties attached to the wall.

BTW, I talked to a guy who sells rock for a living, (Mutual Materials in Olympia WA) and he said that the "cultured stone", which would be easier to veneer, looks fine by itself but looks wrong when you have real rock right near by. Which we will.

The "box" for the biofilter will probably only be about 2 to 2.5 feet high. I think I want to build it at a height that would be comfortable to sit on the edge. That should make it a little easier - I get the impression that the technical challenges increase as the wall goes higher.

 

[DrCase]

Your on the right track with the ledge on the top block of the filter.
Keep the water level above the ledge , and place smaller rocks half in and half out of the water , Than mortar your bigger cap rocks on top of the small rocks ,the top of the block and your outside wall rocks
It will give you the covered water line you want

 

[DrCase]

Your on the right track with the ledge on the top block of the filter.
Keep the water level above the ledge , and place smaller rocks half in and half out of the water , Than mortar your bigger cap rocks on top of the small rocks ,the top of the block and your outside wall rocks
It will give you the covered water line you want

 

[Telkwa]

Sounds like a plan. Thanks, Doc!

 

[Oldhead]

kind of like this