Stone Retaining Walls

Retaining Walls - Stone

   The colors and textures of rock add a natural, handcrafted look to a wall. Build either a dry stone wall (without mortar) or a wet stone wall (with mortar). A dry wall, right, relies on the weight of the rock and an angled batter to hold it in position. You simply pile the rocks in layers, wedging soil between rocks to steady them.
   Mortar allows you to use rounder rocks that would otherwise tumble down. Neither type needs a concrete footing if you keep it under 3 feet high.
   To help support the wall, stones stacked dry should angle back 2 inches for every foot of wall height. Mortared walls should angle back 1 inch per foot. To help you check and maintain the angle, build a batter board.

Step by Step: A Dry-Stack Stone Retaining Wall

This 3-foot-high dry wall uses fieldstones or flagstones. The wall is 12 inches wide at the top, 16 inches at the base.

1. With stakes and string, lay out a 16-inch-wide trench and dig it 10 inches deep. Compact the soil at the bottom, and level the trench by adding 4 inches of compacted sand.

2. Set the largest rocks into the trench as the bottom layer, working from corners to center.

3. Fill voids with soil before laying next layer. With your batter board , check that the wall angles into hill at 2 inches per foot of height. Use a 4-foot mason's level to hold the batter board plumb.

5. Every 2 or 3 layers, extend longer rocks into the hillside to add more anchoring.

Tools

batter board
4-foot mason's level
wheelbarrow
shovel
mason's line
rubber mallet

Tool and hardware-related resources on the Web