How to Construct a Concrete Pond
Estmating the materils
Excavating
To drain or not to drain
>Placing the forms
Working with Concrete
Pouring the Floor
Setting
Fountains and Spouts
There are two ways of setting the inner form into position. One school of pond builders advises lowering the form into the excavation and chocking it up into position by wedging rocks under it. If you do this, be sure to use rocks large and heavy enough not to be knocked out of position when the concrete is poured. Be sure, also, that you take particular care in working the concrete in solidly around the rocks, or the pond floor will not be watertight. Hold the forms in place with temporary braces running from them to study stakes driven into the ground nearby.
A more workmanlike method is to suspend the forms from two-by-four supports, as shown in Drawing 9.
Whichever approach you take, remember that placing the forms is the most exacting phase of the work. When the forms are in place, check them, and check them again with a carpenter's level secured to a straight board. If they are off-level, don't try to balance the corners with each other. Work from one corner only, bringing the others to a level with it.
Before you fill the forms with concrete, paint them with a coat of used motor oil, which any filling station will supply without cost. Untreated wooden forms are often difficult to pull away from the concrete.
You can buy reinforcing steel for concrete, or you can use scraps of iron and steel that you have on hand. Scraps of pipe are good if they aren't more than 1 1/2 inches in diameter. Materials no larger than coat-hanger wire do not add enough strength to concrete to pay you for bothering with them. A coat of rust on the scrap won't hurt, but scrap with paint on it must be scraped or burned down to the base metal before it can be used.
Any concrete dealer will have for sale, or will tell you where to buy, reinforcing steel, either in pencil-rod form or in sheets of highway mesh in which the rods are joined to form a 6- or 8-inch mesh.
Line the pond excavation with reinforcing steel, as shown in Drawing 8, so that the concrete walls and floor will envelop it evenly. The reinforcement can be held in place along the floor by stones.
If you use scrap steel for reinforcing, imitate as closely as possible the 6- or 8-inch crisscross pattern of commercial reinforcing steel. Before pouring the concrete, lay the pieces of scrap into position on the pond floor, and wire them together wherever they cross.
Use the same crisscross pattern of reinforcing in the walls. Thrust in the pieces of scrap perpendicularly and lay them horizontally into the wet concrete as the pouring progresses.
Concrete structures need reinforcing most at the corners where wall meets wall and where wall meets floor. Reinforce these places with pieces of scrap about 4 feet long, each bent to form a right angle. These can be seated in the wet concrete as you pour.