koi pond curved walls

[Thermo]

After tapping into some builders advice on this one.

Ive got a client who wants a koi pond, that will be in the shape of an hoour glass. Its going to be a minimum of 2'6" on one side and 3'6" on the other. Im just trying to think through the best way of supporting the walls, as they will obviously be curved. Theres also quite a lot of trees etc nearby so it needs some sort of solid wall to prevent roots coming through.

Any easy ways to do curved formwork, or will it be easier to do it in masonry. The overall dimensions of the pond are 16 feet x 8 feet.

Mods, please dont move to garden section!

 

[stuart45]

I built one years ago in our old house in Portslade, and used 9 inch brickwork. I did a concrete ring in the ground first, dug down till the chalk got a bit hard, and then built up about 18ins high off the ring. You might have to use snapped headers in the tighter parts of the curves if the perps are going to be too big.

 

[Thermo]

how spookey, this ones in portslade! I was thinking along those lines, i just wondered if there was an easy concrete option.

 

[Jasonb]

For the straighter sections use 100mm dense concrete blocks laid flat and for the tighter sections of the curve use brick on edge which will match the coarsing of the blocks.

If it was just straight sides then you could use hollow concrete blocks and infill with concrete which is how I did my pond

this is a good guide to the most up to date pond construction methods for a decent sized koi pond.

If the 2'6 & 3'6" refer to the depth then thats too shallow for koi, minimum 5ft at the bottom drain(s)

Jason

 

[stuart45]

I did mine in brickwork as the facework was showing and not rendered. I don't know if using formwork would be easier for you. For me brickwork was easier as I'm a bricklayer. Mine was about 3 ft deep, but the Koi never really grew very big, and I was told it was too shallow.

 

[Thermo]

For the straighter sections use 100mm dense concrete blocks laid flat and for the tighter sections of the curve use brick on edge which will match the coarsing of the blocks.

If it was just straight sides then you could use hollow concrete blocks and infill with concrete which is how I did my pond

this is a good guide to the most up to date pond construction methods for a decent sized koi pond.

If the 2'6 & 3'6" refer to the depth then thats too shallow for koi, minimum 5ft at the bottom drain(s)

Jason

thanks, i did point out it was shallow, but this is what the client wants!

 

[noseall]

You can achieve most curved radii with bricks Big T. As said if the curve is to severe for a stretcher brick then use a snap header.

Finishing the top of the wall may be a challenge though...

....i'm guessing all will be rendered no?

 

[Thermo]

brickwork doesnt bother me, easy enough to do, i was just wondering if there was another option

 

[noseall]

Don't be fooled by the visual simplicity of formed concrete walls, they ain't easy to do. Shuttering concrete is tricky and requires a fair bit of effort - curved walls require boat loads!

 

[Thermo]

yes i kind of figured you would say that. just the complexity alone of the formwork when i was working it through in my head seemed to limit it, but i just thought id get a reality check!

masonry it is then!

cheers chaps

 

[Jasonb]

Or do as the americans do and use Gunnite - sprayed concrete

Jason

 

[ColJack]

would you need re-bar in a wall that size? 8-12 inches wide and about 2-4 foot high ( no idea on the size of the pond.. ) ?

 

[Jasonb]

I'd put mesh in the base and also set starter bars into the base where the walls are going to be. Then tie in some rebar to these when doing the walls

A lot depends on how you are finishing the walls, rendered and then fibreglassed will give a stronger wall than render sealed with G4 as this is more likely to crack

Jason

 

[moonman999]

Just built this for koi, ICF available in curves too. Holds 2800 litres, 1 mtr deep (800mm Water), took 2 days to build, now full, though no pics yet.

Lined with rubber
all pipes inside
lights also recessed.
top edges done with decking,
Stone effect Deco pierreadded by local guy.