Pond problem

[DaveOC]

Hi
I'm in the process of digging out a garden pond just over 3m x 2m and
900mm deep in an oval shape. 300mm down the ground turns very very stoney in hard clay a lot of flint and bricks far too many to try to remove.
I was going to use a protective sheet before putting down the butyl liner. Can anyone offer any advice as to what to do to help protect the liner, as I'm not sure the protective sheet will be man enough. Some one suggested foam back carpet,I could use both???

 

[Mike290955]

Dave, when I dug out my pond, I put some sand in between the earth and a layer of old carpet. Seems to have done the trick - no punctures.....yet!

 

[stuart45]

I did the same as Mike, only I mixed a small amount of cement with wet sand to help it stick to the sides and plenty of old carpet. It surprising how much pressure there is a couple of feet down.

 

[breezer]

Old carpet and time do not mix, which is why carpet is not a godd idea.

The carpet will decay over time, as it does so the space it did take up is now less (all the air space has gone) as there is less carpet there is now less support for the liner. This makes the liner more suseptable to tears / peircings.

If how ever you never jump in the pond to clean it out (you should) then you will get away with it for a while, but its when yopu jump in to clean it and there is no support under the liner that is when you will puncture it.

Most liners come with 20+ year g'tee, however this is usualy void unless you also use their brand of liner underlay, using old carpet, newspaper etc voids the g'tee.

 

[snico]

Try to remove most of the stones and bricks as you can. It is time consuming and a pain but it must be done.

When you have most of the stones out, put down a generous layer of sand. You can put old carpet down if you like, it wont cause any harm, if you do make sure you put more sand over it.

If you buy your liner from a local shop or one that you are going to visit, ask them for some liner off cuts to use, they usually have some lying about.

A decent liner over that will be fine and shouldnt cause you any problems, you can always buy the corect under liner, depends what your budget is

 

[Symptoms]

Dave - you must bust through this 300mm rubble barrier and get down to near your 900 depth (you wrote: " ... the ground turns very very stoney in hard clay a lot of flint and bricks far too many to try to remove." 300's too shallow for any pond.

Anyway, you only need to use a good layer of damp sand below the liner (damp will allow you to shape the pond profile and will allow it to stay in place 'till the liner goes in). A couple of scaffold boards (to act as a bridge if necessary) will be handy.

 

[breezer]

The deeper a pond is the better, koi keepers aim for 6 feet deep, although its a bit OTT for a garden pond. You could always have half and half. Half sunk half raised, this has the advantage nothing can get blown across the surrounding area and then fall into the pond, since the pond is now raised.

 

[snico]

The deeper a pond is the better, koi keepers aim for 6 feet deep, although its a bit OTT for a garden pond. You could always have half and half. Half sunk half raised, this has the advantage nothing can get blown across the surrounding area and then fall into the pond, since the pond is now raised.

Thats the way I eventually built mine, mine is 3/4 sunk with 1/4 raised.

What type of pond does the OP actually want?

 

[DaveOC]

Thanks for the replies, I will use sand and an underlay. Maybe mix the sand with some cement?? do you think this would be a good idea???

 

[breezer]

no

 

[DaveOC]

Why no Breezer? I thought it would help to hold the sand up on the vertical sides of the pond, which is where all the flint and stones are.

 

[Thermo]

no breezer is right. if the sand is slightly damp, it will hold itself in place as you dress the pond with it. Once the underlay and liner are in place the pressure of the water will do the rest. I agree with breezer about the liner.its cheap and does the job. we always use a sand blinding layer and a layer when we install a pond. Its going to be there for years so you may as well get it right to begin with.

God knows ive repaired enough of peoples old ones and its a real pain to do!

 

[breezer]

Why no Breezer?

Its a waste of cement.

What do you think it will do? No, what will it really do?

At worst it will add some colour to the sand, at best it will turn the mixture hard. What good did that do? none. If it goes really bad a shard of mix may puncture the liner.

If you must use sand, use sand. no cement.

I personaly dont like that either because i am always worried that as most people will apply it wet, it will dry out and if there is not enough of it it will fall down. A proper pond pre liner liner can never do that.

I Have pre lined my pool with...................

a liner.

Its only been there for about 8 years, but the abuse i give it ............

 

[snico]

Just use damp sand, dont put cement with it!

I hope you enjoy your new found, and expensive hobby

I got the pond bug years ago, my bank manager keeps reminding me!

 

[Thermo]

Why no Breezer?

Its a waste of cement.

What do you think it will do? No, what will it really do?

At worst it will add some colour to the sand, at best it will turn the mixture hard. What good did that do? none. If it goes really bad a shard of mix may puncture the liner.

If you must use sand, use sand. no cement.

I personaly dont like that either because i am always worried that as most people will apply it wet, it will dry out and if there is not enough of it it will fall down. A proper pond pre liner liner can never do that.

I Have pre lined my pool with...................

a liner.

Its only been there for about 8 years, but the abuse i give it ............

you can virtually gaurentee it wont dry out breezer due to the moisture in the ground. as i said before it wont move anywhere anyway due to the water pressure. i still do belt and braces though with a liner!