Project of the Month: December

This month will be continued over into the next few months due to the complexity of this job.  We implemented most every service and skill on this location including:  stone walls, patios, cobblestone walkway, irrigation, planting, and lighting.  For this month, we plan to focus on the stone wall.

Tools needed  for Stone Wall Installation:
1.  Level
2.  String
3.  Wooden stakes
4.  Flat shovel
5.  Hand tamp
6.  Rock hammer & Sledge hammer
7.  Chisel
8.  Wheel barrow 

1.  Layout the wall area and direction. You may be cutting away a bank as can be seen in this project, or building the wall and back filling as you go to create a terrace effect. Pull a string line the length of the wall to define the front of the wall about 8 inches off the ground level. 

2.  Dig a ditch the length of the wall that is about a foot wide and 8 to 12 inches below the ground level. This ditch will act as the wall's footing and prevent the rocks from sliding forward by pressure from the earth behind.  Fill the trench with crushed stone up to the soil line to create a level foundation and after compaction spread granite dust or sand to provide a level surface.

3.  If drainage could be an issue, a french drain should be installed prior to the first layer of stone as seen in this picture (gravel behind wall).  There is a perferated pipe with sock below the gravel to direct water away from the front of wall.  For more info on how to build a french drain, click here.

4.  Stack the larger rocks in the ditch, with a flat side facing forward, and slanted back about 8 degrees. The rock should just miss touching the string line, and be supported by dirt filled in behind it. Do this the length of the wall with each large rock touching the one next to it.

5.  Fill dirt behind the large rocks and tap the earth firmly, while letting the 8 degree slant hold the rock in place by gravity.

6.  Find complementary rocks to fill in the spaces between the large rocks. These rocks may be smaller but need to be a shape that fills the void between the large rocks. Lay the rock flat side out and support it with earth filled in behind it. These rock also lay back by 8 degrees.

7.  Continue placing the second layer of rocks so that spaces between the first layer of large rocks are filled. You can add water to the fill to make it settle.

8.  You can overfill the void with dirt and then tap the rock into place with a small hand-held sledgehammer.

9.  This is what the finished wall looks like.  Reserve an amount of large, very flat stones to use as capstones to top off the wall  to give it a nice straight flat appearance.
Tips:

1. The choice of rock is very important. Angular, flat, stacking stones are much easier to work with than round field stones.
2. For the long term stability cut your foundation trench into native soil rather than loose bedding soil. The native soil is less likely to move around or settle.
3. For walls that are above 3 feet tall you want to create a 3 to 4 inch lean back into the soil. Do this by stacking each progressive layer about 1/2 an inch back. This will prevent the soil pressure behind the wall from pushing the stones out over time.