Bench Class

A couple of weekends ago, I led a workshop at the NC Arboretum on building stone benches. First thing in the morning we studied images of various benches, stone-cutting techniques and ways to move heavy objects safely and with relative ease. Safety was a recurring theme throughout the day. After the classroom presentation, we went outside and built a free-standing bench, a style I call castle-block for the big chunks of stone that make up the supports. The bench we built is now a permanent fixture at the Arboretum, a rest station along one of the trails.

To facilitate ease of movement, we cut the big stone down in the back of my truck. In this image, Ronnie is using a star bit chisel to notch shallow guide holes in the top of the stone. This gives the drill bit a place to sit, reducing the likelihood of the bit bouncing around and scarring the stone.

Everyone got a chance to use the drill and work at cutting stone. Here Judy leans into the drill to get the proper placement.

Since our cut edges were going to be exposed, we took some time to clean up the drill holes. Here Carol is using a handset chisel to knock off the cut edge of the bench stone. We put the cut edge to the back of the bench, less visible to passers-by.

We spent some time doing bench math, designing everything so that it would be the proper height and balanced as a structure and as an aesthetic object. Here Carol measures the thickness of the slab, the starting point for figuring out the math. I handed out the following worksheet to guide the design and layout process.

By cutting it in the back of truck, we made the stone more manageable, but it was still a heavy chunk. Jason uses a rock bar to move the stone from the pallet onto the ramps we have set up. Using 2″ by 12″ pressured treated lumber as ramps, we slid the stone down to waiting blocks and from there into place.

We used mortar to set the bench. This design can be done dry, but the mortar reduces the risk of movement, particularly since the bench is in a public place.

We all felt good as we finished up. The bench looked great and we had built it efficiently and safely. It felt good to be leaving something cool and useful for everyone to enjoy. Tre and Ronnie test drive the bench and pronounce it good.

Mailbox Vault Done: Stone Theory

Mailbox Vault Done

Here’s the scene at the entrance to the Rock Hill horse farm. The connecting wall will top out at about 28 inches, so there’s a bit more to go. The far column has some sample caps resting in place. Columns of this volume might require a massive cap to help visually anchor them. That decision hasn’t been made yet…

Mailbox Vault Done
Here’s a front-on view of the mailbox vault shortly after completion. I’m very partial to this style: structural quoins, solid stone lintels, serious gravity. It’s a mix of old school and new style. My conservative estimate puts each column weighing over two tons.

This is a plan from my tiny notebook that I eventually scrapped, in favor of thinner stones for the quoins, adding an extra pair of stones in order to make full height. I worried that at almost 7″ thick, the quoins as drawn would be out of scale to the rest of the work.

Detail looking down the quoins.

This Northern Fence Lizard spent the night resting in a nook in one the block I used for my low scaffolding. It was a very safe place until I started work in the morning. I had to move him because he was too cold to move himself. His tail is obviously shortened, perhaps by a predator, perhaps by not being careful enough around the stone pile.

Column Theory: Stone Mailbox Vault

Stone Mailbox Vault

Last week I spent a good bit of time creating this structure within the column to house the biggest mailbox I think I’ve ever seen. I cut these quoins from step slabs, using petty much every technique I know how to tim them down. The cut-off saw was too loud and dusty and the line would wander over the full 36″ of the stone. Using the hand tracer chisel worked, but was really only efficient when I was cutting the shortest lines. Eventually I settled on cutting a clean line at each edge with the small grinder and then using feathers and wedges to cut the rest. This allowed me to keep my quoins fairly symmetric, but let me go more quickly than I would with chisels alone or even using the saw. Perhaps someday I will do a time trial to see which is faster, though I suspect the old school wedges (and an electric hammer drill of course) are faster than my Stihl saw with a diamond blade on it. Feathers are more fun too.

Stone Mailbox Vault

This is a detail of the armature that I am building the columns around. This is intended to provide a place for the wooden cross pieces to be hung and held away from the stone work. By doing this, the wood is more easily maintained and switched out as needed. It also protects the stonework, by reducing the chance that the wood will soak up a bunch of water and hold it against the mortar. Whenever wood juts into stone work, it inevitably creates a weak spot in the stone structure. This armature design also provides a place where I can mount my corners template, a piece of plywood with string stretched plumb to the footer. I got this idea from Fred Lashley; I don’t know if she invented it or adapted it from some other source.

A banker is a mason’s work table. You can’t see from this angle, but this table is minutes away from falling over; it has a significant, persistent lean. That’s a chunk of Arkansas Hackett sitting on the corner.

Stone Column Theory

Stone Column Theory

Stone column for an automatic driveway gate

Stone column for an automatic driveway gate

My latest project is the entrance to a horse farm just outside of Rock Hill, South Carolina. Mortared columns and connecting walls frame the main gate. I’m using a Tennessee sandstone as well as Arkansas Hackett, a type of sandstone akin to Tennessee Crab Orchard but darker in color. The client already had a supply of this stuff, snapped strips about 5-6 inches tall and about the same thickness. It makes a lovely cornerstone. The metal fins sticking out the side will hold wood fence rails.

I’m working on a theory that columns- which I find to be one of the most challenging and intriguing expressions of stone- are like short stories, compared to the long form of walls or novels. There’s a different rhythm and a greater attention to detail is needed to achieve the desired result. You need all the same elements in a short story as novel- strong characters, a compelling plot, beautiful language, but you have less space to develop it and if you miss it, well it’s painfully obvious. And multiple that by four, since each side of a column is its own piece, but visually and strucutrally connected to the other sides. Stone columns are a common item in around here, and yet few capture the imagination. I’m hoping that this set will really pop.

Radial Steps: Tread two and landing installed

Stones laid dry to test fit

It really did take two weeks to get this step installed. We had a wicked cold snap, with at least a week’s worth of days that didn’t go above freezing. But the last two days have been in the fifties and it’s felt like summer. In the image above, you are looking down onto the bottom two steps. The lowest step is eight feet across. The landing narrows down to six feet. There are small points on the outermost stones on the landing, that almost look like little horns, pointing back at the camera. Those will be cut square and columns will rise up alongside the step. Four steps will rise above the landing, with the radius reversed, curving back into the hillside.

A mason friend is restoring a chimney around the corner. I scored a whole mess of scrap bricks from him, which I have been using for fill. Because the bricks are old and some are breaking down, I am only using them inside the structure. No bricks will be used where they will be vulnerable to moisture

The image to the right is of the bluestone laid dry to test the fit of the stones. So far the templating system has worked beautifully.