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.