Article No: 279

2010-09-24 11:12:13
Tranquility, Reflection, Ambiance
By: Sue Marquette Pormeba


Concrete boulders in a water feature must fit naturally into the landscape.

Waterfalls, ponds, in-ground pools and spas are becoming popular backyard decor. These soothing landscapes bring a touch of nature into urban neighborhoods and provide a pleasant backdrop for outdoor entertainment.

The rock work that make up waterfalls is a misunderstood art form, according to Philip di Giacomo, and he ought to know.

Now affiliated with Concrete Hardscapes in Denver, Colo., di Giacomo has been a rock artist for the past 50 years.

Too often, he said, the focus is on the overall design of the water feature, and the rocks are almost an afterthought.

Instead, the concrete boulders and stones should fit naturally into the landscape. Water should flow through the rock naturally, and the rock shapes and coloring should blend in with the natural stone formations in the area.

To create the boulders, di Giacomo said he uses the same technologies he learned in art school. We learned to make small molds, he said. I took the same technology to boulders. The molds I use look real because they are taken from real rock.

The rocks and boulders are often created with rebar and glass fiber reinforced concrete (GFRC) and carved with a diamond saw. They can be solid or hollow, depending on the placement of the rock or special features designed into the overall feature.

Jody Smith of Overlay Solutions LLC in Summerville, S.C., said a hollow center enables features such as lighting or speakers. Hollow is also nice next to a swimming pool where less weight is desired.

Solid rock is best used in natural features such as waterfalls, where weight is less of an issue but aesthetics are important.

Coloring the concrete boulders follows the same general principles of standard decorative concrete projects, Smith explained. You start out with a scratch coat, and then you come over that with a texture coat. After that, you can use mattes for the rock face.

The next step is to stamp the concrete and finally carve in details to make the rock use natural.

Smith uses a variety of acid stains and acrylics. Dyes can also be used to get different effects. Whether an acid stain or an acrylic is used depends on the overall look desired. The acrylics will create a softer tone.

Because concrete is porous, it is important that the rock is well sealed. Dave Montoya of Stonemakers in Manchester, N.H., uses a high-strength mix with a hygroscopic product added to absorb the moisture. An acrylic is also added to the concrete to make it waterproof.

One of the problems often encountered in building waterfalls and similar water features is leakage. We make our waterfalls of solid concrete and they leak under liners, Montoya said. We use the liner directly under the concrete and seal from the inside out.

Overall, maintenance of the water features is fairly easy. Smith suggested a regular maintenance program of pressure washing the rock and sealing it.

Sometimes youll have hard water stains, and when that happens, the artist or contractor will need to come back and recolor the concrete. Smith offers to come back to do touch ups or fix surface cracks that are bound to happen because, well, concrete will crack.

Perhaps the biggest challenge in designing and building a waterfall or pond is making it look aesthetically pleasing and natural while working within the homeowners budget. To do so requires a great deal of cooperation between homeowner and contractor.

Placement is vital. The water feature should be placed in an area where it can be easily adorned with plantings. Rock should be arranged so the water appears to be flowing naturally and not falling over a piece of concrete.

But the waterfall should be where the homeowners will get the most enjoyment from it. A back corner of the yard seems to be the default location for many homeowners, but it is likely not the most logical place for its scenic value. Water features also shouldnt be placed too closely to patios or decks. First of all, according to Smith, a feature too close to a patio will limit the size to something smaller than what the homeowner may have wanted. Secondly, the sound of the water falling over the rocks interferes with conversation if it is too close to the deck.

The most vital consideration to planning, designing, and building any water feature, said di Giacomo, is the enjoyment the family and their guests will get from its addition to the homes landscape. Its my job, he said, to make sure the experience of adding the feature is enlightening and enjoyable.

Sue Marquette Poremba is a freelance writer based in Central Pennsylvania. She writes regularly on decorative concrete, construction, engineering and technology.