As I began to dismantle the original pond, I realized that there was absolutely no underlayment or support for the liner. It had several holes and was likely going to leak forever. Rocks and debris with sharp corners were exposed under the existing liner, making them easy puncture targets.
The 2x4s used to support the edges also supported some 1/4″ cement board that didn’t go all the way to the bottom. When the pressure increased from the water, it would literally run under the sharp edge of the cement board and run the risk of puncturing the liner again.
I removed everything, but kept the liner in case we needed later.I excavated the area until it was flat and added some topsoil to smooth out the base. Next, I took 4x4s and cemented them into the four corners. I wasn’t able to sink them into the ground, so I could only pour about 2″ of cement around each of the four posts.
I then built a frame for the pond walls out of pressure treated 2x4s. I also purchased some “sound-proofing” panels that worked perfect for the underlayment. I used cement board for the walls AND floor and then applied the underlayment.
Since I was planning to go from the original waterfall location to the second pond, I built a platform into the pond to support the structure that would move the water. I also used the underlayment and duct tape to make sure there were no hard edges.
I purchased a new pond liner and spread it out . I stapled it to the 2×4 walls on the opposite side of the water and filled it up. It held the water perfectly with no leaks. I also reinforced the the side next to the new faux-retaining wall to support the rocks.
At some point during this process, I managed to fall and throw my back out. I was unable to work on it for about a month because I literally couldn’t move.
Also, the heat was so bad that I could only work on it at night. And since I was having to lift and move a lot of heavy rocks by myself, progress was slow.