Dry Stack Boulder Retaining Wall

For this landscaping project we were approached by the owners to build a boulder retaining wall. In our first meeting, we found out that they wished to expand the gardening space available, deal with a problematic lawn, and maintain the rustic look and feel of their existing landscapes.

We decided thus to go with a landscape of boulder retaining walls as that provides the more rustic look and feel they were going for while meeting their desire for a larger gardening space. The general outline of the space and its boundaries were established and a schedule was set to commence.

Landscaping boulders were selected from a trusted local yard and shipped in, along with about 6-8 cubic yards of top soil.

A shallow trench was dug along the perimeter of the area to be landscaped to give definition to the boundaries and as a guide for boulder placement. This was done using a mini excavator. Boulders were carefully placed and the retaining wall slowly built based on their shape, size, and stability. Larger boulders were placed on the bottom and there needed to be sufficient stability since this was a dry stack wall, meaning there was no mortar to hold it together. Therefore we had to be sure from a safety perspective to keep the wall structurally sound via its own geometry and weight. A slight setback was also established to counter the impending top soil that would be pushing out. Finally we had to maintain a level top on a slopped surface, necessitating a higher wall stack at the foot of the slope than at the top.

Since the boulders were exceptionally heavy, most were lifted via the mini excavator. Once the boulder was dropped in place, it was rotated by two people to the correct and stable location. An excess of boulders were ordered due to the random nature of their size and shapes to ensure there would be enough to make a nice looking and level retaining wall.

Once the retaining wall was built to satisfaction in terms of aesthetics and stability, the mini excavator was used to transport the many yards of soil into the new space. At the top of the slope, the soil was around 1 foot deep. However, near the base there was about 3 ft of top soil. Care was taken not to bury the pine tree at the bottom of the slope as well. Once this was done, the top soil was raked to perfection. Finally, a small tree that was ordered and requested was planted in the center.

The owners were very pleased with how it turned out and were eager to utilize it in their gardening immediately. We were extremely happy with the outcome and their enjoyment of this new space.