Hi everyone

[POD]

I have had a "professional" landscaper to create a pond about 3Mx2Mx0.75M I have since had to take it out and start again. My main problem is the state of the ground, Before we bought the house the previous owners put the cinders and fire waste at the back of the garden where the pond is going. This means there is a layer of waste about 150mm below the soil that is unstable. there is also a lot of bind weed roots in that area plus a lot of rocks etc.
Is there any way I can stabilize the ground to take a liner without the top edge breaking away or should I try a preformed liner.

 

[Lisak1]

So I take it this is not where the original pond was installed?

Whether or not you can stabilize the ground depends greatly on the composition of your soil. Clay soil is easy - you can just wet it and then tamp tamp tamp until it's hard as a rock. Sandy or loamy soil is not so easy. But 150mm is less than six inches, right? Can you dig all that unstable material out and replace it with soil that you dig from the remainder of the pond? Or maybe a cinder block wall construction would be better. A preformed pond wouldn't do well in unstable soil either - they need to be level and stay level or they will crack.

 

[sissy]

Welcome and cinders and waste will make the soil loose but not unstable but it would be a great place for a garden .You could use concrete block to stabilize the walls and still use a liner or find a better place for the pond

 

[Becky]

Hello and welcome to the forum!

 

[POD]

Thanks for the responses. A few points brought up; the soil is clay lower down but very loose and crumbly for about two feet (600mm) down. We have nowhere else we can position the pond. removing the cinders and replacing with the soil from the hole would have been a good idea but the "professional" landscapers removed the waste. The concrete or cinder block wall sounds like a possibility, I will look into than. Many thanks again.

 

[mgmine]

If you let the liner hang over the sides enough and cover it with dirt it shouldn't be a problem. On the other hand if you cut it off and leave a small amount the it could get dragged into the hole. I would think that even with loose cinders after a year the ground should have settled. If you are concerned then rent a power tamper and force the ground solid.

 

[Dave 54]

Welcome to the forum from a rather cloudy Plymouth UK
Cinders ahh the bane of our lives, why well we discovered that the pathway above our pond which is concrete and 3" deep was held up with you've guessed it with nothing but Cinders which means the path in one section of the pathway dropped slightly and weve had to underpin that section of path to stop anymore subsidence .
You could if you wish pad out the cinders with old carpet then a layer of sand before your liner goes in .
That way the cinders dont have to be dug out and would be no danger to your liner ,

Dave