Courses, Joints, Capstones, Coping
I like to use brick walls to explain dry stone concepts, and I’ll probably never find a better demonstration photo than this one on website of the Dry Stone Walling Association of Canada. Brick wall concepts are straightforward: The vertical line between each brick is a joint. Each horizontal layer is called a course. Each course should break the joints of the course below it, a brick laid across the top of each individual joint. That way, if a joint starts to crack open, the opening can only run a single course before it bumps into something solid in the next one; it’ll have to staircase it’s way up instead of splitting along a straight line.
Stone walls built with rectangular stone work the same as a brick wall. A dry-stacked wall uses the heavier mass of the stone, greater thickness of the wall, and batter (a slight lean into the hillside or towards the center of the wall) to make up for the absence of mortar. Like with bricks, the stones should be laid flat, and the joints should be broken. Every stone should sit on two stones instead of just one, and in turn should have two stones sitting on it. It’s a good idea to occasionally break the horizontal joints with a double-high stone, but it’s not really necessary. The builder of the wall in the photo did a good job absorbing the irregularities of the stone into nice horizontal courses with sufficiently broken joints.
The wall also demonstrates two ways of capping a wall–with a large flat capstone, or with coping stones stacked vertical like books. Personally, I usually find vertical coping stones a bit self-conscious for my taste, but in this case the stepped coping works perfectly for this already self-conscious wall.
Having said all that, I’m not sure what this wall is for, other than a great demonstration photo. It’s kinda random. With natural stone and brick right next to each other, one material is bound to suffer from the side by side comparison. And you can’t usually see the bottom of a stone wall; this wall sits on a pedestal like installation art.
But it’s definitely cool. It reminds me of the topiary rooster near my house–an effective execution of a somewhat quirky design idea. I would never have done it, but I like that someone did. I don’t know what it’s for, but it has heaps of personality, and personality counts for a lot.
ryan 1/7
This entry was posted on Wednesday, January 7th, 2009 at 3:11 pm and is filed under stone, walls. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.
January 8th, 2009 at 12:55 pm
It’s a very nice example of wall building. Could be a one- pallet-of-stone kit. Do they sell those ?