How to Build a Fence to Last a Lifetime

Dig a flat-sided trench 15 inches deep, 20 inches wide and as long as the fence requires. Tamp down the bottom of the trench with the hand tamper. Spot check the trench bottom level every few feet with a bubble level and adjust the depth accordingly to level it out throughout the length.

Drape landscaping fabric over the trench so that it covers the interior completely and is a few inches above the ground level on each side.

Pour six inches of pea gravel into the trench, being careful not to tear the fabric, and level it off. Place a block of limestone over the gravel at the start of the fence, with the long side running from side to side of the trench. There should be a 1-inch gap between the end of the block and each side of the trench. Place another block in the same fashion next to it and tap it with a mallet to force it close to the first one. Continue to add blocks until you reach the end of the fence line. This is the base of the fence that the other blocks will rest upon. Check every few blocks to ensure that the base is staying level.

Place your first block for the fence lengthwise on the base about 2 inches in from the edge. Because the base is 18 inches wide and the block is 12 inches wide, you should have about 3 inches of base on both the front and back of the block. Mark around it with a marker and lift it up. Now that you know where the block is to go, trowel about 1/4 cup of mortar onto the base, thinly spread under the first block. Keep the mortar about 1 inch from each edge of the marked line. Place the block onto the mortar and seat it firmly by pushing down and wiggling it.

Continue to lay the block in the first row in the same fashion until you get to the end. After the second or third block, you will know where to spread the mortar and will no longer have to mark the blocks and then lift them up. Lay the mortar directly on the lower base and seat the blocks. Use the mallet to tap the block close to the one next to it. You want them to be as close as possible. The end block should be one of the half blocks that is only 9 inches long.

Lay the second row in the same manner as the first row, except start the first block with one of the 9-inch blocks. This ensures the vertical seams of the blocks are always offset. Complete the third and fourth row, starting first with an 18-inch block and then a 9-inch block. After the fourth row is laid, you should be about 3 inches above the soil line. Fill the space in between the stone and the side of the trench with more pea gravel, ensuring that the landscaping fabric is pressed against the soil, not against the fence block. Level the gravel off with the soil.

Complete as many rows as you need to reach knee-high. This is about 20 inches, so about 10 rows will be needed. This gives three rows underground for support, and seven rows above ground for the fence.