Please Help with a wooden above ground pond.

[Steph3773]

Hello...I am new here! We are in the process of having an above ground pond constructed. Actually we thought we were done with constructions except siding...we even had fish in. It is being built by a well recommended guy, but I don’t think he has. Done one this big above ground Without a premise hard plastic form.

The pond size is 10x12x3foot deep. The inner wall is 3/4 inch plywood, and the outer wall is 1/2“ plywood. The top of the frame is 2x6’s and the bottom is 2 rows of 2x6’s. As best I can tell, these were not attached to the paver and concrete pad that the pond sits upon. Every 12 inches or so, there is an additional 2x6 upright, positioned like you would when framing a wall. We have an underpayment between the pavers and the liner. it looks to me that they used 2 1/2” deck screws on the inside and. 1 1/2} deck screws on the outside. And there was both an adhesive of some type and 2 1/2” screws holding the base together.

The pond was completed except siding a few days ago. The siding, when it comes will be Airstone...a cement mixture product of recycled glass(10-20%), Portland cement(14-30%), expanded clay(20-30%), quartz(10-25%) and slag(10-30%)....but it will be a couple of weeks before that gets done. There will also be a granite or quartz counter on one 10’ side.

Water was put in the pond, about 30” and the fish. Yesterday afternoon, my husband was outside and walked around the pond to the back side. The plywood and one corner of the base frame had come apart....to me it looks like from the weight of the water?
The pond has been drained and the contractor has moved a tank, aerator and filter and the fish into our screened porch.

what recommendations do you have to fix this? I am not letting those fish back in the big pond until I have some confidence it will be ok.
Thanks in advance for any help you can provide.

 

[mrsclem]

Not using plywood! We just emptied our 10x10x5.5 above ground pond because the walls were bowing out. Pond is 10 years old and was built with 2x12 lumber and 4x4 posts every 2 feet. Posts were set in 3' of concete. Screws will rust, we used 1/2" galvanized bolts and 3/4" lag screws.
The volumn of water you are dealing with is close to 17000lbs. Plywood and screws are not the way to go. If I had to do it againg, I would go with block and cement.

 

[mrsclem]

Why not dig a hole and drop in a liner?

 

[Steph3773]

Thanks Mrs. Clem....I think the issue was breaking up the concrete pad....and the thought that pipes to the pool go under the pad....not so sure about that. And that in order to expand our screened in lanai, 18” of concrete pad will be added on two sides, requiring rebar. I think the actual poundage of the pond is almost 23,000! I hope there’s a way to salvage this....it has been ridiculously expensive.

 

[mrsclem]

I calculated what water you had in there. If they are already doing concrete work, why not switch to a block walled pond? Our wooden pond would never survive another winter if filled all the way.

 

[Mmathis]

Hello and welcome.

Can you post pictures — of the pond and the surrounding area?

 

[Steph3773]

I calculated what water you had in there. If they are already doing concrete work, why not switch to a block walled pond? Our wooden pond would never survive another winter if filled all the way.

I am floating that idea right now...if nothing else, block wall between the up and down posts.

 

[Steph3773]

Here they are. It’s hard to see some of it, because the existing screened area is still there. BTW, the window is 3 inches thick and the fish love it...when they were in the pond, they would rush to the window when they saw us!

Hello and welcome.

Can you post pictures — of the pond and the surrounding area?

 

[j.w]

@Steph3773

 

[Mmathis]

I wish I knew more about constructing ponds like this, but my gut tells me this is all wrong. Water is extremely heavy, and needs really good support. I’m with @mrsclem. Just curious, but how is the 3” thick window attached? Can’t tell anything from the pics.

 

[Steph3773]

I am not sure what it is, but it’s an adhesive sealer product that I think the window provider recommended.

 

[mrsclem]

You say the builder is recommended but you are unsure about his skills. Why move forward if you are having doubts? Will he give you a refund if the pond fails?

 

[Steph3773]

he has built lots of beautiful ponds and was recommended by a specialist in koi. I just think he hasn’t built one like this before.

 

[Mmathis]

he has built lots of beautiful ponds and was recommended by a specialist in koi. I just think he hasn’t built one like this before.

He may be used to building in-ground ponds.

 

[MountainBound]

Concrete would probably be a better way to go. Making a form and doing a solid pour would be best, but you could prob also do cinder blocks and fill the cavities with rebar and concrete. Downside is that it's pita to remove if you wanna change things up 5-10 years from now or if you decide to sell/move.

Wood is doable, but you'll either need some beefy timber (like railroad ties), or 2x_ lumber with a bunch of 4x4 cemented posts to withstand all that pressure (and maybe even some poly or steel strapping to prevent bowing). This route could be more expensive than concrete though. Plywood just isn't a good fit for this project. It's too weak and will be near impossible to prevent from rotting after a few years no matter what you cover it with. Moisture will find it's way in. You can also use stainless steel screws/lag bolts to give some extra rust protection, but they are a little more expensive.