Installing boulder walls is fairly simple compared to segmental concrete retaining walls because each 3-foot to 4-foot boulder can be set with equipment, while blocks have to be stacked by hand. For this reason, the cost of boulder retaining walls can range from $25 per face foot to $55 per face foot.
How tall can a boulder retaining wall be?
Three feet is the maximum recommended height of a stacked stone wall built on a clay surface. It is also the stable height of most stand-alone stone walls. Sandy soil doesn’t absorb water, making it ideal for building a retaining wall without reinforcement.
How do you estimate a boulder wall?
How to Calculate a Stone Retaining Wall
- Determine the average length, width and height of the stone in feet.
- Multiply the length, width and height of the wall to determine its cubic feet.
- Divide the total cubic feet by 15 to determine the amount of stone needed in tons:
Why do boulder retaining walls fail?
When residential retaining walls fail, it is most often due to poor drainage. Using boulders ensures that excess water can drain through the wall. Boulders come in a variety of sizes. The wall height usually determines the size boulder that is needed.
Are boulder retaining walls good?
Boulders are Usually Good In general, boulders make an absolutely phenomenal building material. They never suffer from weathering or erosion, salt degradation has absolutely no impact on them. So let’s start talking about how boulder retaining walls are typically built the wrong way.
How much does a 3 foot boulder weigh?
How much does a 3-foot boulder weigh? A sandstone boulder typically weighs about 150 pounds per cubic foot. That means that a round boulder that is 3 feet in diameter, or 27 cubic feet, weighs about 4,300 pounds. Limestone and granite are a bit heavier at 175 pounds per cubic foot.
How many tons of boulders do I need?
Calculate Landscape Boulders
| Coverage (Square feet) | 400 | sq ft |
|---|---|---|
| Volume (Cubic yards) | 2.5 | cu yd |
| Estimated amount (Pounds) | 5,951 | lb |
| Estimated amount (Tons) | 2.98 | ton |
| Amount +15% compression | 3.42 | ton |
Does a boulder wall need drainage?
Due to the weight and shape of the rocks, no mortar is required when constructing a sturdy wall. A major advantage of boulder retaining walls is that they offer natural drainage. When residential retaining walls fail, it is most often due to poor drainage.
Do I need drainage behind boulder retaining wall?
Boulder retaining walls also will need a certain amount of drainage and base material depending on the subsoil conditions. But if your soils are soft and compressionable, you’re going to want to fortify that base by laying something down before you put the boulders in place.
