Waterfalls are design features that add ambience to any outdoor space. You can make a stone waterfall to fit in a corner of a patio or as a focal point in your backyard or garden. Slate is a good choice of stone for building a patio waterfall; the slabs are easy for one person to handle. Natural slate stones are available at most landscape supply retailers.
Place the large rectangular planter at the desired location for the base of the waterfall. The planter is the reservoir for the waterfall. Use a rectangular planter at least 5 feet long with a depth of at least 16 inches to catch the water as it flows from the slate waterfall. Seal any drain openings in the planter with silicone sealant.
Stack natural slate stones along the front and two sides of the planter. Run a bead of waterproof construction adhesive between each stone as you stack them. Stack the slate stones slightly higher than the rim of the planter. If you prefer, slate is also available in pre-cut tiles that will make a more uniform waterfall design.
Line a row of breeze blocks on the ground behind the planter. The breeze blocks should extend from one end of the planter to the other. Glue the blocks together on the sides with a generous amount of waterproof construction adhesive. Place and glue another row of breeze blocks on the ground behind the first row. Continue to add rows of breeze blocks to the desired back edge of the waterfall. You should have a breeze block pad from the back edge of the planter to the desired back of the waterfall.
Stack and glue another layer of blocks on top of the first layer. The top breeze block should be 4 to 6 inches higher than the planter's top rim. If you must add another layer of blocks to exceed the rim of the planter by 4 to 6 inches, do so. The concrete blocks will create the elevation for the waterfall so you can limit the amount of slate stones needed for the structure.
Stack another layer of breeze blocks on top of the previous layer, but begin this layer one row back from the edge of the planter, as if you were creating a stair step design. Glue the breeze blocks together with a generous amount of waterproof construction adhesive. Continue to build the waterfall structure to the desired height by adding successive levels of breeze blocks. Always begin the next set of blocks one row back from the previous row. This stair stepping effect will create a cascade for the stone waterfall.
Cover the breeze block structure with plastic pond liner, available in rolls from landscape supply stores. Glue the liner in place with waterproof construction adhesive.
Cover the breeze block structure with natural slate stones. Glue the slate to the plastic liner with waterproof construction adhesive. Make sure the stones along the edge of the planter extend over the planter's rim at least 4 inches. This will camouflage the planter as well as help the water flow into the planter. Allow the adhesive to dry at least 24 hours.
Place the waterfall pump inside the planter. Run plastic tubing from the pump to the top of the waterfall. Position the end of the plastic tube in the centre of the waterfall. Attach the tubing with duct tape and camouflage it with another slate stone. Fill the planter with water. Start the pump.
A preformed plastic pond liner works as a reservoir for waterfalls in the garden or backyard.