Concrete pond leaking


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Hello friends, I have recently dug a new pond. My pond is 4' in the ground (concrete totally) then an additionally 3' cinder block up above ground. I finished the entire wall with mortar. Then sealed the entire interior with a product called POND SEAL. Filled pond up. ALL WATER LEAKED OUT except about 5" in the bottom. Next I consulted a local Pond expert. He said use Herculiner truck bed liner(same product as a pond SEAL sold by that company but marketed much cheaper) Coated the interior with one(1) coat, and filled pond up. I did see improvement. But after 5 days I am at about 3' left in pond. I did notice that I had seepage at the mortar joint connection between the in-ground concrete and the above ground cider block structure. But I can't figure out the issue with the below ground water loss. Should I apply a second coat of the Herculiner? Or is there any thing I can add to the water that will find the seep points a fill them? Or just drain the whole thing and buy a plastic liner to fit into the structure? Any answers?
 
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brokensword

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it's going to cost but you'll get piece of mind and some enjoyment out of your pond, and freedom from fixing; get a pond liner. EPDM or HDRPE. Doing a concrete pond is best left to specialists, imo, as you need to provide for water pressure and weather conditions ala frost and freezing. And, imo, a liner pond is a lot cheaper because you can diy with minimal loss of integrity. A concrete pond should be done by someone with experience in the trades. For instance; mortar is not waterproof; cement is (assuming you meant concrete and not concrete blocks; if blocks, they are not made for sheer pressure, they're made for compression strength). EVEN if you coat the walls, you're probably going to get cracks unless you reinforced your concrete wall.

With a liner, it won't matter then if you get any cracking of your walls. Hence why it would have been better to forego the concrete/+cost and just let the earth handle the pressure.
 
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It would have been better if you had put a plastic liner under your project but your fail will always be at a straight walls base, lots of movement right there. What will work is elastomeric coatings and I suggest 10 layers at least. I used Bluemax with good results. I built a 24,000 gallon pond with concrete and it has cracked in several places but with the liner underneath no leaks.
 
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I agree...drop an EPDM or HDRPE liner in there and be done with it. Either one will suffice. They are flexible and will hold water even with expansion and contraction.

I always remember that saying...there are two types of concrete, one that's cracked and one that's going to crack.
And with your project set in the ground, there are too many variables. Constant expansion and contraction. Freezing, unfreezing, the pressure of the water pushing out, etc...

To me, experimenting with different "waterproofing" products can be expensive and frustrating. Do it right...use a liner, fill it up and enjoy your new pond.
 
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it's going to cost but you'll get piece of mind and some enjoyment out of your pond, and freedom from fixing; get a pond liner. EPDM or HDRPE. Doing a concrete pond is best left to specialists, imo, as you need to provide for water pressure and weather conditions ala frost and freezing. And, imo, a liner pond is a lot cheaper because you can diy with minimal loss of integrity. A concrete pond should be done by someone with experience in the trades. For instance; mortar is not waterproof; cement is (assuming you meant concrete and not concrete blocks; if blocks, they are not made for sheer pressure, they're made for compression strength). EVEN if you coat the walls, you're probably going to get cracks unless you reinforced your concrete wall.

With a liner, it won't matter then if you get any cracking of your walls. Hence why it would have been better to forego the concrete/+cost and just let the earth handle the pressure.
Yes, I know now. Have spent almost $600.00 on the concrete and block and sealer. Think I have micro leaks in the concrete sealer and the weight on the water is pushing it out but slows as the water level gets lower. I'm in coastal Virginia so freezing is not a problem. Was looking for a liner of 20'x15' but they cost. Pulled my liner up that I was going to use under the water fall and use it. But guess what? Holes in it!!! Can't seem to catch a break. Maybe I can try liquid rubber. Drained the thing the other day and at bottom I could see tiny voids in the Herculiner that I think is my leakage problem. Going to try and fill them good and fill it up again. Whole thing is holding up my other yard projects and the waterfall.
 
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It sounds to me it may be time to cut your losses. Concrete ponds if not done by someone not experienced in concrete it a ticking bomb and only a matter of time until it fails and when it does it is usually a spot here and then a spot there. so on and so on. i Have gone up on roofs and seen nails sticking through a rubber roof and in a puddle yet no leak. is this always the case no!! it is common yes!!!
 
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Thanks. I think you are correct. Still leaking SOMEWHERE?. Going to get a liner. What about "waterproof tarp"? Cheaper than liner.
 
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Window boxes are tricky but not impossible. A threaded rod through the frame nut and washer poked through in your case cinderblock through the underlayment through the liner. Pack silicone on a sturdy metal bar drilled out for your rod washersand nuts slip your glass under the bar make sure you don't over tighten . You will probably need some type of expansion material to allow for expansion contraction. Snug up tge nuts tighten evenly as you go Aquascape did a video on there new fish sales area and how they did it. It sounds harder then it is
 
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Best part about Epdm is it is often used as a gasket which is exactly what your looking to do
 
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I just found this product today. Liquid Epdm. I called, talked to a rep, was told after it has cured, (3 days at 55f steady temps) it’s completely fish safe. It’s a two part deal, the epdm, and a catalyst, at $95 for a gallon, which covers 45 ft, can be rolled or brushed on.
 
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if you have epdm why not just order firestone adhesive and patch it once and for all. the liquid epdm would have been great to seal the dead pool to the negative edge rock so the water level stayed a bit higher the water level drops oh so slowly the 6" that is the thickness of the negative edge rock
 
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It would have been better if you had put a plastic liner under your project but your fail will always be at a straight walls base, lots of movement right there. What will work is elastomeric coatings and I suggest 10 layers at least. I used Bluemax with good results. I built a 24,000 gallon pond with concrete and it has cracked in several places but with the liner underneath no leaks.
Movement due to the weight of the water? May explain my fast water loss when full, but as level goes down it seems to slow until it seems to stop at about 1 foot.
 
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Concrete blocks are ok to give the shape, and hold a liner. That is all. Had you done a monolithic pour of concrete bottom to top, you would have been better off. But still, it is porous and will lose water at a very slow rate, so it must be sealed.

But, as you've already used blocks, this product will be the best to use: https://www.merlex.com/super-blockade.php
 
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