I have a few questions that I need answered before I can give you an answer. Does the masonry wall go all the way down to where the cement floor will be? Does the masonry wall go all the way around the pond? How large is this pond setup? How the top of the masonry wall be capped off?
Mike

I have a similar question about water-proofing a a small poured concrete pond. The size is approximately 9ft by 4 feet by about 3 ft deep. The bottom, the walls everything is concrete. I will be using tufa rocks and some river rock to cap it.

Like persiancowboy I will like to know how to properly waterproof it using something non-toxic.

The two pond area are 20'x5'x2'deep & 20'x8'x2'deep and the swimming hole is 15'x8'x5'deep in between. Masonry walls go down to large concrete footing, where the concrete floor will be (or above the footing) I have poured the floor yet (I am also need to design the plumbing and lighting) Masonry walls are also filled with concrete and curved crown on the top. I had read products Drylok or thoroseal are inexpensive way to seal. thanks

I have used Drylok a lot. We used to use it to seal concrete trout raceways in one of my old jobs. I know for sure that it is fish safe and waterproofs really well. You just have to put on three coats or so, and you should start out with a fairly smooth surface. Of course, it will not fill gaps.

Thoroseal is also very good at waterproofing, but if I remember right, it is quite a bit more expensive - at least from my supplier. Also, I don't know if it is fish safe or not.

Persiancowboy,

Is one wall of these ponds exposed all the way to the footing or do you have a five foot high wall exposed? If so I hope you have had an engineer determine if this wall can take the more than 36,000 lbs of force that it will see and that will increase when people in the pool start to move around causing waves. If it was my ponds I would use liner. It can easily set under the cap or attached just under the cap with termination strips. The liner may have to be seamed together to get the shape of pond design. If you don't want any folds in the corners than you can fit the liner to the shape but this is a little harder and you may want a professional do this. If this is not acceptable than I would suggest one of two options. The first is to coat everything with CIM 1000 which is going to be somewhat costly or have it sprayed with Polyurea liner that will be more costly. The CIM will cost roughly $2.00 per square foot if you install it yourself and the Polyurea will run about $12 to $15.00 per sq foot to have someone do it for you. You can not do this yourself. I would not trust any other products. Now to answer your question as to if I know what I am talking about. I am a pond professional and I am certified by Firestone. I have also used the two products that I suggested.

Tropicofcancer
Everything said above would apply to your pond except the force the walls will see.

Mike

Mike, thanks for the info. What kind of place will carry CIM 1000? Looks like it is a two part epoxy from their website. I may be wrong on that.

A liner will be tough since there are many corners. I will have to think about it.

Tropicofcancer,

Like an epoxy it is a two part product but that is the only thing similar between the two types of products. Epoxy is a rigid product and if the cement moves or cracks the epoxy will fail. Over time the epoxy will probably fail. The CIM is a rubber product that will flex with movement and can stretch. Properly installed will last about 60 years. It has to be mixed with an electric drill mixer for 3 minutes. After mixed it is to sit for two minutes before using. Once mixed it has a working life of 20 minutes. The whole time it is getting thicker. I use the trowel grade. One person can easily do one gallon in the 20 minutes. When I use 5 gallons it requires at least 3 people and the product is getting pretty thick by the time that 5 gallons is gone. They say if I remember correctly that one gallon will cover about 25 square feet but I usually get about 15 sq ft. which means I put it on thick then the 60 mils that they say should be used. Fresh concrete has to set for thirty days before coating. It also has to be primed with their primer. That is brushed on and covers about 450 sq ft per gallon. CIM will adhere to a lot of different surfaces including non porous surfaces like rubber liner, brick, concrete and some plastics. When first installed it will be glossy and after six months will turn dull even under water. I have used it 6 ft under water with no problem.
I buy it from a local company called Sealant Engineering.
Mike

Mike, Thanks for the info. I will have to look around for a source and read a bit more.

This might be helpful:
http://www.quikrete.com/PDFs/Projects/GardenPoolsAndFountains.pdf

Here is a link that might be useful: Quickrete pond instructions

I live in Vancouver, BC and my vote is for Thoroseal .. I have heard/read good reports about CIM and Drylok ..

Thoroseal in my opionion isn't expensive, I drove down to Blaine and picked it up for $34 a bag, you need to preorder it ahead of time as they typically don't keep stock. I got it from Ace Hardware. I also got the Stock Tank from here.

Stay FAR FAR away from POND ARMOR. Worst product and very expensive .. I made the mistake of buying this, wasted $200 which I had to then spend a couple of days removing.

I have also since extended my pond. A single bag will probably cover $250 square feet, I used two bags for each section of the pond + some Acryl 60.

Here is an older blog I created on the subject. I am also on a hillside.

It's been two years and so far so good with Thoroseal.

Here is a link that might be useful: Concrete Pond

To Tropicofcancer: If you've built your own concrete pond, do you really need to seal it? I'm assuming you and Persiancowboy haven't (yet) built bottom drains or side drains or plumbing for circulation/filtration systems, if you're going to do so. This sounds like you're building swimming pools, not ponds. If you're not a licensed geologist, structural engineer, plumber, and electrician, do you really want to be building your own swimming pool? I would at least consult with some licensed professionals before you either build something unsafe or something semi-functional that risks wasting all of your investment. The one thing I've learned is that you got to plan it completely and test it in smaller stages if you want it to come out right.

I would **highly** recommend Permaflex from Sanitred:
http://www.sanitred.com/WaterFountain.htm

Some of you may remember me from years back. I have a concrete and natural stone pond that leaked like a sieve. Two years ago the cement cracked so badly over the winter that we had to drain it to fix it. We had used hydraulic cement and Dryloc but frost heaves in the surrounding rock-filled clay created a lot of movement during the winter.

After a lot of research I found Sanitred. The liquid rubber retains some flexibility in the cracks and the top coating of Permaflex (I used beige) seems to hold up well. It cost me about $500 but it's held well for two winters now. It wasn't any more difficult to work with than other paints. They recommend doing everything in one day but we took two or three. The Permaflex can be a bit slippery and they recommend adding a little sand to the final coat. I didn't because I didn't paint the solid stone pond bottom.

Here is a link that might be useful: My Pond - not updated recently ;-(

I had not noticed that there were more comments to this thread. Well I was not the original poster anyway.

s8us89ds: I understand what you are saying. I did consult with an engineer before building the pond. It is quite small - about 500 gallons or so capacity. It has a bottom drain. It will have some basic plumbing for water falls and some filtration. Not planning on putting any fish just some water lilies.

basilbird: I did look at sanitred and found it quite an appealing solution, especially for DIY. I did research into CIM1000 as one poster suggested but have not found a suitable source yet. CIM1000 sounds like a more appropriate product though but may be a bit more difficult for DIY.