How does one incorporate green building techniques when it comes to building stone walls? That is an interesting question – the answer to which is riddled with many twists and turns based on what you are building, what materials are being used and how it is put together.
It is a question I have delved into more deeply in the past. (Check out my article on Building Green with Stone) Here I would like to discuss dry-stone wall stacking and how to improve on its environmental impact.
Most of the time when a client selects a variety of stone for their wall, they are basing their decision entirely on the color and texture of the material. Maybe they want a dark brown hue to complement the color of a nearby fence or a blue-grey to match the trim on their windows. While this is a logical approach and may lead to some nice esthetic results, it does not take into account the amount of energy needed to complete the project.
Let us take into consideration that a great deal of stone materials cannot be broken or split by hand with any degree of accuracy, and necessitate a heavy reliance on diamond blade saws for shaping and fitting. A good stone wall takes an enormous amount of time to complete, whether hand-split or sawed. But when every piece requires a saw cut, the noise that is created can be a nuisance and the amount of energy (gas or electricity) consumed is a factor that must be considered, especially if one is attempting to reduce the carbon footprint of their home construction.
The solution to this problem is to avoid these harder, less-workable varieties which would include quartzite, slate, granite, and other metamorphic minerals. Instead, going with a softer stone like sandstone or limestone allows for the possibility of shaping the pieces by hand using a carbide chisel or a hydraulic splitter.
This kind of hand-made method is a science unto itself and not every mason is sufficiently capable with it. There is a need to try and fit pieces as they are with minimal cutting (as opposed to “making it fit” with massive saw cuts), as well as a familiarity with the character and behavior of a given mineral to make the most of its workability. In my opinion, having built walls using both methods, the chisel-oriented method yields the most pleasing results.
A dry-stack stone wall is meant to look rustic. When the stones are too tight and too rectilinear, you lose the natural and pastoral qualities that make the medium so appealing in the first place.
The other thing to remember here is that choosing a local stone is always best when attempting to keep your process green. Here in Washington, in terms of hand-workable materials, we have the light-beige Wilkeson Sandstone, the medium-grey Tenino Sandstone and Columbia Grey (aka Camas) Basalt.
Some other good varieties that are not local are Texas, Fond-du-Lac and Huckleberry Limestones, Arizona Sandstone, and the old favorite Pennsylvania Bluestone (a kind of sandstone often mistakenly called slate).
So when it comes to sustainable stone construction, going old-fashioned means going green.
by Mark Shepherd www.ShepherdStoneworks.com
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