Above Ground Brick Pond

[Steve P T]

I am in the process of building an above ground brick garden pond and really need some advice regarding the construction.

1. My pond will be built into a sloping garden.
2. The pond height (ie the brick wall) will be about 300mm above ground at one end, and about 900mm above ground at the other end.
3. It will be kidney shaped so both ends will be curved.
4. The concrete footings are in and are 450mm wide by 150mm deep.
5. The overall length is approx 4m and the width is approx 2.5m.

I was initially thinking of doing a double skinned wall using standard concrete bricks for the inner wall, and facing bricks for the outer wall. However, at the end which is approx 900mm high, I am not sure if this method of construction will be good enough to withstand the water pressure.

Any advice would be much appreciated.

 

[theprinceofdarkness]

rough figures 1m of water ~1.5 PSI, side area of brick = 9 X 3 = 27 sq ins, so force = 1.5 X 27 ~ 40 lbs for bottom brick, next brick up = 40 X .925 (3 " less water depth) , next one up 40 X .85. . . top one = 40 X .075. I reckon that with a good mortar bond it should be OK. I think the biggest problem is the pressure of the water on the "tall" bit of the wall will rotate the foundations. As at a rough approximation a one brick wide section will have 30 " X 9" X 1.5 X .5 (average pressure) = 200lbs trying to push it over.
You say your foundations are 150mm deep, thick or deep?. At a depth of 150mm you are still in top soil in most places. This all looks a bit hairy to me .
Frank

 

[Steve P T]

Thanks for the info.

The foundation are dug down in firm soil and are 150mm thick concrete. Can you reccomend what my best way forward is. Eg. Thicker wall, different bricks, etc.