How to Build Cement Outdoor Fountains

Dig a hole for the fountain foundation. For a small fountain, you can use a concrete paving stone as the foundation. A foundation is necessary to ensure that the fountain remains level and does not sink into the soil. Make sure the stone is large enough to hold your fountain pond liner.

Place the pond liner in the hole atop the foundation stone. Make sure that the edges of the liner are level.

Build your fountain form. The form fits around the mold, holding it stable while you pour the concrete and while it sets. Small forms can be constructed from rigid foam insulation. Larger forms should be constructed using wood. To create your form, assemble an open four-walled box that the mold can sit firmly in, and place the mold in place for filling with the concrete.

Mix your concrete in a wheelbarrow with a hoe for pouring into the mold. You need to mix one part water with two parts cement and three parts sand to create your concrete. This should create a concrete that sets smoothly, without a rough texture. If you want a particular type of concrete look for your fountain, however, such as one with small polished pebbles throughout the stone, you can go with a pre-mixed concrete instead. Mix the concrete until it has a consistent texture.

Perform a slump test with the concrete to make sure it has the proper consistency. Take a styrofoam cup and remove the bottom, invert the cup and fill it with the concrete mix, sliding the cup off onto a flat surface. If the concrete retains the shape of the cup when you remove it, then you need a bit more water; if it slumps, losing about half of its height, then the concrete is of the proper consistency to work with. Too much slumping and you have to add more of the cement and sand to the mixture.

Fill the fountain mold with the concrete. Fill the mold by dropping concrete into it on all sides as you raise the concrete level. This will ensure that the mold doesn't bend, creating bulges or wrinkles in the fountain. As you fill the mold, use the flat of your spade to tap against the mold side to make sure any air bubbles move to the top.

Allow the concrete to wet cure for a full week before removing the mold. Cover the fountain with a plastic sheet, weighed down to slow evaporation and allow the concrete to set completely for three more weeks.

Finish the construction by removing the plastic sheet and placing the fountain into the foundation hole atop the liner. Apply a concrete sealant to the concrete, and then place the pump into the fountain according to the manufacturer's instructions. Wait for the sealant to dry, and then fill in the hole at the base of the fountain. You can now attach the pump to a water supply and enjoy your new fountain.