This article is about a 70-foot-long water feature I built. It has 3 ponds and 4 waterfalls. You can see my photo diary of the building process.
My pond will not hold water
I did just about everything right. However, I made a few mistakes. One of those mistakes resulted in a number of pin holes in the lower pond. As a result, half of the volume of the pond is drained every week. This article specifically tells how I plan on replacing the leaky pond liner with a properly-built wooden pond.
I contacted Butch, the Pond Armor guy who maintains this blog. He very kindly gave me suggestions on what to do about the lower pond.
What I will be doing is building an 8’ x 8’ x 4’ high wooden box and painting the inside with Pond Shield. This article tells what Butch told me about how to build the box. There are more detailed instructions on my Yard Gardener web site.
I will be making the box out of a good 3/4″ exterior grade plywood. (Exterior grade has water resistant glue.) The plywood will be butted together using about 10 biscuit joints for each 8′. (You may need a Lamello or some such grinder tool to make the pockets for the biscuit joints.)
Strengthening the wooden pond
The pressure of the water can cause the boards to bow over time. That will cause leaks even if I plan on having the boards flush against the earth. With rain seeping into the earth & other types of shifting, I have to assume that not all of the boards will always be flush against hard-packed earth. It will be necessary to make lots of wooden ribs (3 – 4″ apart). The ribs around the sides and the bottom should be held together with some type of angle iron. (That is like the iron bands that hold the staves in a wooden barrel together.)
Because plywood can delaminate over the years, I will line this box with a half inch concrete board (Hardie plank). Hardie plank joints will be covered with fiberglass tape.
Then the outside of the box will be painted with tar. Otherwise, over the years, I will have insects & rain water eating into the wood. Sealing the rubber liner to the wooden pond The water course leading to the pond is lined with rubber. The seal where the tank is attached to the rubber liner must be absolutely water proof. The board that will attach to the rubber will have dried Pond Shield on it. The rubber in that area will be abraded to resemble 60-grit sandpaper so that the Pond Shield will adhere. Bolt holes will be drilled. The rubber will overlay the board and be attached with stainless steel bolts. Attach it so that there are no perceptible pin holes.
It is hard to find paint that will adhere to stainless steel bolts. So, go to an auto store and buy a quart of self-etching primer. Prime the bolts that stick out and then apply the Pond Shield, making sure that there are no pin holes whatsoever. I will be working on this project later on this month. Look for a photo diary of it in my website.
Written by Peter Enns ~ Peter currently owns and operates the Yard Gardener. This website grew out of a passion that Peter & his wife have for landscaping, especially water gardening. The Yard Gardener is a great place to learn a wide variety of pond related information as well as cash in on some great deals at our online store. Come visit us and see how you can make a beautiful water garden.