Fish pond construction, brick wall strengths etc.

[Boosted LS1]

Hi, I've got a pond sunk 3 feet deep into the ground at the moment and the floor around it is concrete maybe 5" thick. The triangular pond measures 10 ft x 10 ft and is a bit longer on the third side. I want to add a wall 2 ft high and add maybe 18 inches of additional water. I think that a double row of bricks tied together and bonded to the concrete should be strong enough to contain the additional water but some builders don't seem to know if this is the case or not.

Does anybody know where I can check if my plans seem reasonable or doomed to failure or has anybody built a similar pond? Thanks.

[eddie1980]

So at a guess it sounds like you want to retain about 2.5 tons of water with a wall.

I am well known for over engineering everything I touch so I'll keep my opinion to myself on this one, but would be intrested in the answer.

[993AL]

Dont know if this is the best way but you could shutter it, pour concrete with re-inforcement and tie it in with rods to the existing walls.

[C Lee Farquar]

You should be able to find out what the hydrostatic pressure would be for the volume of water by searching the net, and also the lateral strength of a brick wall. Gut feeling is you're being optimistic.

[GTDNB]

7 newton blocks laid on their sides OR laid on edge tied to outer skin of standard bricks.

you can see lots of builds with pics here:
http://www.koimag.co.uk/forum/your-pond-build.html

will you be lining it with EPDM/butyl or GRP?

[rsv gone!]

Boosted LS1 said:

Hi, I've got a pond sunk 3 feet deep into the ground at the moment and the floor around it is concrete maybe 5" thick. The triangular pond measures 10 ft x 10 ft and is a bit longer on the third side. I want to add a wall 2 ft high and add maybe 18 inches of additional water. I think that a double row of bricks tied together and bonded to the concrete should be strong enough to contain the additional water but some builders don't seem to know if this is the case or not.

Does anybody know where I can check if my plans seem reasonable or doomed to failure or has anybody built a similar pond? Thanks.

You aren't supporting the weight of the water. You need to contain the sideways thrust.

A standard masonry retaining wall (good for about 1.8m of soil) would be;

You have a wide asymetric footing (to oppose the twisting force), which is reinforced. The reinforcement is tied to vertical bars which are tied to a mesh in the 100mm cavity of a brick / block wall. Bricks and blocks are tied together to form the wall. The cavity is then filled with concrete.

[andy43]

GTDNB said:

7 newton blocks laid on their sides OR laid on edge tied to outer skin of standard bricks.

you can see lots of builds with pics here:
http://www.koimag.co.uk/forum/your-pond-build.html

will you be lining it with EPDM/butyl or GRP?

100 wide 7N on their side here too - with an extra course of facing brick around it. Loads of wall ties!



Did I mention ours hasn't been filled with water yet...?

[danyeates]

Here's ours:





Thickness of the wall....



The pond is about 2 metres deep. Don't know how much water is in there, it's been estaimted at 30,000 gallons but I don't know if that's accurate at all!

Edited by danyeates on Thursday 3rd February 09:57

[danyeates]

GTDNB said:

7 newton blocks laid on their sides OR laid on edge tied to outer skin of standard bricks.

you can see lots of builds with pics here:
http://www.koimag.co.uk/forum/your-pond-build.html

will you be lining it with EPDM/butyl or GRP?

Funny you should mention that magazine, this is our pond on the front cover!

http://www.koimag.co.uk/magazine/issue/136-summer-...

It's a good read and shows the contruction diary.

[Boosted LS1]

Thanks for the replies and links. I've been over to the Koi forums, what a fantastic place to look around.

[Boosted LS1]

Well, it seems to be that an inner wall of concrete breeze blocks and an outer wall of brick will do the trick. In fill between them with a concrete mix. Or use a double course of bricks tied together. Both methods have worked on similar ponds.

[headcase]

danyeates said:

The pond is about 2 metres deep. Don't know how much water is in there, it's been estaimted at 30,000 gallons but I don't know if that's accurate at all!

If you dont know that how did you spec your filters and flow rate? And what about if you need to add a treatment to the pond?

Boosted LS1 said:

Well, it seems to be that an inner wall of concrete breeze blocks and an outer wall of brick will do the trick. In fill between them with a concrete mix. Or use a double course of bricks tied together. Both methods have worked on similar ponds.

Thats exactly how im building mine, 7N 100mm concrete blocks (they weigh 7.5KG each)and an outside skin of brickwork in the places it can be seen and the edges that run along the fence line then its a double block, all tied together obviously and if you do build it with a small cavity then filling it with concrets/soil wouldnt do it any harm

This is my construction thread here, http://www.pond-life.me.uk/forum/viewtopic.php?f=9...

Im currently building the blockwork as weather allows.

[Boosted LS1]

^Good build link.

The builder laid the first row of bricks this morning and we've decided on a double course of bricks tied together and finished off with double bullnosed bricks on top. Should be finished in a couple of days .

[dave_s13]

headcase said:

Thats exactly how im building mine, 7N 100mm concrete blocks (they weigh 7.5KG each)and an outside skin of brickwork in the places it can be seen and the edges that run along the fence line then its a double block, all tied together obviously and if you do build it with a small cavity then filling it with concrets/soil wouldnt do it any harm

This is my construction thread here, http://www.pond-life.me.uk/forum/viewtopic.php?f=9...

Im currently building the blockwork as weather allows.

SOrry to be a miserable sod but.... I hope you never want to sell your house.

I'm not being funny but you appear to have used a large proportion of your back garden for the pond?? Maybe other space though??

I'm a fan of ponds but one that size, in that garden would put me right off.

The 2m deep job pictures above is splendid btw. It's bigger than some swimming pools!

[Mr GrimNasty]

Ponds are very personal things. With the amount of effort going in I doubt he's moving soon! Most pond owners accept that they may need to demolish/fill in when the time comes to sell. It's quicker than building anyway!

[Spudler]

fk me!...that brickwork makes me feel seasick

No way a bricklayer laid those

[headcase]

Nope, I wouldnt build something like that if I wasnt staying. The pics may be misleading, the pond takes up one corner of the garden less that 1/3rd of the total.

[headcase]

Boosted LS1 said:

^Good build link.

The builder laid the first row of bricks this morning and we've decided on a double course of bricks tied together and finished off with double bullnosed bricks on top. Should be finished in a couple of days .

Take some photos, id be very interested on its progress

[GTDNB]

nice to see you on the koi forum, boosted.

danyeates said:

Funny you should mention that magazine, this is our pond on the front cover!

http://www.koimag.co.uk/magazine/issue/136-summer-...

It's a good read and shows the contruction diary.

stunning pond - i recognised it as soon as i scrolled down and saw the first pic. may i ask who did the fibreglassing for you?

[RichB]

As there are a few pond people on this thread can I ask if any of you have ever seen an unobtrusive way of fully netting a pond? Problem I have is not herons, although they are around but mink! I kept losing fish 'til I saw one of the blighters robbing my pond...

So new pond built in the autumn, 10' dia x 4' deep 1500 gallons/6500 ltrs. I'm thinking of gluing some hook-eyes under the lip of the slabs with resin onto which I can hook some guy rope rubber elastic over which I can stretch the fine net. Any ideas?

My new pond.