How to Build a Pond with Landscape Timbers

If you love the sound of a waterfall, the sight of aquatic plants and water lilies swaying in summer breezes and goldfish darting like glittery underwater butterflies, a pond is for you. Ponds are expensive to build yourself and more expensive if you hire a professional to build one for you. Here is one way to have a unique pond, built by you, easily and in a weekend. You can have a showpiece in your garden for very little money and a bit of ingenuity and hard work. Landscape timbers have two flat faces on the top and bottom and two convex faces on the sides. The timbers are 2 3/4 inches thick, 4 inches across and 96 inches long, so they are great for pond making.

Making the Frame

  1. Choose a level location in your garden for your new pond. Decide the size and shape of your pond. This example is for a 4 x 8-foot pond, but you can make yours any shape, any size. Remember to buy a liner that will cover the bottom of the finished pond, go up the sides and over the top.

  2. Set up the circular saw. Cut one of the 8-foot timbers in half to 4-foot. Now you have two 8-foot timbers and two 4-foot timbers.

  3. Lay one timber across the top of another at a 90-degree angle using your combination square. Mark the bottom timber and start to make kerf cuts with your circular saw. Set your circular saw blade to a depth equal to half of the depth of the timber or 1 3/8-inch. 
You will make your kerf cuts so the timbers line up at each corner at 90 degrees and fit together like Lincoln Logs. Kerf cuts are 1/8-inch to 1/4-inch grooves in the timber half the way through the wide side.

  4. After you make kerf cuts in the ends of every piece, cut out the excess wood with a hammer and chisel. Cut half lapson the ends of each side piece and end piece.

  5. Lay out two side pieces and two end pieces to form a rectangle. Use your square to guarantee your rectangle is square on the ends. Find the centers of the lap joints and drill a 3/4-inch hole through them Locate the center of each side piece and drill a 3/4" hole through the center of each side piece. The holes are for the rebar to fit through and the rebar will stabilize the pond. Use the drilled pieces as templates to drill the rest of the timbers. 

  6. Lay out the bottom row of timbers and using your maul or sledge hammer drive the rebar through each hole approximately 6 inches into the ground. Continue to lay rows of timbers until you have placed them all with the rebar through each drilled hole. The timbers are joined at the corners by the half laps so they fit together and make a perfect rectangle. The rebars add structural strength.

Placing the Liner

  1. Cut the roofing felt in about 8-foot pieces and place them sideways in your box so they cover the ground and go up the sides of the box, covering the landscape timbers. Cover each end as well. When you are finished, every surface inside your box will be covered.

  2. Place the liner in the box so the it comes up the sides of the timbers and laps over the sides

  3. Fill the pond with water.

Finishing the Pond

  1. Cut one of your 1 x 6 x 8-foot boards in half. If you wish to paint the 1 x 6 x 8-foot boards, so do now. Paint them on all six sides. These boards will hide the top edge of the liner and give the pond a finished look.

  2. Nail the 8-foot' pieces to the long ends of your pond. Nail the 4-inch pieces to the short end of the pond. When you place the 1 x 6-inch boards on the pond, make sure they stick over the inside of the pond and make sure they are nailed into the liner on top of the landscape timber box. The overhang will camouflage the liner.

  3. Remove any excess liner or roofing felt.

  4. Add dechlorinator to the water.

  5. You may add fish and plants now. If you have a pump, add it now with a fountain attachment if you wish or a waterfall in one corner. Use flat rocks to build a waterfall.