Does it sound counterintuitive to incorporate cut rock into a natural water garden, waterfall, stream, pond or swimming pond? Why would you even consider it? How could it successfully enhance the design, usefulness, interaction opportunities, and your client’s enjoyment?
I’m guessing that when you think of cut rock, your mind may instantly go to straight lines and sharp corners. This is far from the reality I hope to explain and demonstrate in this article. I hope to banish forever the myth that cut rock in a water or garden feature should be avoided.
Some people even infer that cut rock lowers the overall quality of the finished work. They think it diminishes the skill of the installer if that person has to cut the rock to make it work in the feature. My efforts here are to shed some positive light on this subject. I offer ideas for using field-cut rock to enhance a project, be a solution to a difficult situation, or become a creative opportunity.
Seeing Rock as Art
At the start of my professional business in 1989, I had a very narrow vision of pond building and rock installation. With so many random shapes and sizes of rock available, it seemed easy to get them to fit together. I had never even thought of why one might want to significantly cut a rock. I was focused on sourcing rocks that had character, and I worked hard to install them in an attractive manner.
It was not until my chance encounter with Anthony Archer-Wills in 1997 at the International Water Garden and Waterlily Expo in Chicago that I was exposed to true artistry with rock. After that, I never looked at a rock the same way. I learned that you can make rocks into beautiful planters, veneers, staircases, steppingstones and more.
I also learned that not all ponds, streams and waterfalls are built using flexible liner. Many are built from structural concrete. These vessels, some even resembling swimming pools, benefit from someone who is skilled with rock and can naturalize the concrete contours and flat surfaces to build realistic-looking shoreline edges and waterfalls within the pool structure.
It is safe to say that almost all of us started our careers using basic tools like shovels and wheelbarrows to dig our ponds. We used rubber or clay to make them watertight. What I would like to introduce in this article is an atypical, alternative technique that adds value for your client, profits to your bottom line and prestige to your company when the skill is learned and the work executed correctly.
Starting Small with Rock Cutting
Rock planters or basins within or adjacent to the water feature are a popular and attractive detail. To make a rock planter or basin, we select a rock or boulder, typically of the same material used in the water feature or landscape. We size it appropriately and ensure it’s free of cracks. We carefully cut and carve out a major portion of the interior, leaving reasonably thick exterior walls for structural integrity. Drain holes in the bottom of planters are critical. On porous rocks such as coral, it is important to seal and waterproof the interior walls.
Another popular use is steppingstones for pathways, staircases or crossings over a stream or pond. For pathways and staircases, we typically cut the rock into 7-inch-thick slabs. This provides considerable structural integrity, and I have found 7-inch risers on a staircase to be a comfortable height.
One of the rules we try to follow is to select rocks that are no thicker than the bar length of the chainsaw. This way, the saw can cut through the rock completely and not have a broken edge where the rock snapped and broke away. Once the slab is cut, we remove the fine saw marks from the surface. This rotary bushing tool leaves a textured, non-slip surface like a sandblasted finish. If we have a stream or pond to cross, we adjust the thickness of our cuts to ensure that we end up with 2 to 4 inches of rock sitting above the water level.
Larger Projects
One day you may encounter a request to build a waterfall, and there just is not enough room. We were called into a staircase waterfall project very late in the process after all the concrete structures were poured. Our dilemma was twofold. First, we could not get the desired size crane near the project, so we could not use full-sized rock. Second, if we used full-sized rock, there would be no room left for the staircase steps and lower waterfall basin. The solution required using only the portion of rock seen by people using the staircase or viewed from the upstairs patio. The custom-cut rock veneer looks and feels like full-sized rocks, but in reality, the rocks were only 3 to 8 inches thick.
If it has not happened yet, there is a good chance a pool builder may approach you to build a rock waterfall inside of or flowing into a swimming pool. In this situation, the pool vessel will likely be concrete. As in the pond industry, when doing water’s-edge details, you will want to hide the bottom portion of the rock by submerging it in the water — preferably below the bottom edge of any potential tile line. To do this, you will either need a support bench built within the pool to set your rocks on, or you can cut the back and bottom of the rocks with a right angle cut so it can sit on the top of the wall or beam and hang down the face of the wall.
In some cases, a designer or client may want to have one or more rocks sitting on a patio structure or look embedded into a staircase. To build these different affects, we trim the rock to fit flush to the location.
Cutting Rocks?!
Now, I know it sounds crazy. There can’t possibly be a good reason to cut a big rock in half.
Well, actually, there are quite a few reasons. In some countries and islands, there is not a ready supply of rock. Or, if you find the rock you want, it is too great an effort to arrange extraction and hauling. As with many projects, design changes may eat into the schedule and leave you without time to source more rock. For one project, the large crane we had on site ultimately could not extend to the added work areas with a 9-foot rock hanging off the end of the boom. Because time was a critical factor, we determined it was more efficient to cut these larger rocks in half. This would provide twice the number of large rocks without any more extraction and hauling. With lighter rocks, we could now extend our work area and range with the crane.
One of the more extreme cutting tasks we took on started out as a challenge thrown down by the client. While on an adventurous hike, he found a remote staircase cut into the face of a solid rock that provided access up a difficult slope. While standing at the base of the staircase, he sent me a photo. He asked if I could replicate this at a location on the project. Never having done this before, I, of course, said yes, and set off trying to figure it out. Fortunately, we were nearing the end of the project, and I had a few large, odd-shaped rocks remaining. Out of those remaining, I selected three rocks, all about the same size, and started staging, marking and cutting them. Ultimately having multiple rocks was a blessing, because it allowed the steep staircase to wrap around a significant rock formation.
Rock Cutting Puts You a Cut Above the Competition
Like many other trades, rock cutting requires an investment in tools and management of a learning curve. To separate your business from typical water-feature companies, you need to find ways to build ponds better or offer a unique value. The desire to be creative and have your projects stand out from others makes the time spent enhancing your capabilities and skills worthwhile. Once learned, this technique provides endless opportunities to be on the cutting edge, and also a cut above.
About the Author: David B. Duensing is a longtime waterscape and hardscape designer and builder with an extreme passion for natural rock. His firm, Aquatic Construction Services (ACS) specializes in the construction aspect of natural rock formations and living water features.
