Northern California is an amazing place to visit. There are many places along the coast where the lines of stratification in the rocks are all diagonal. Its stunning to see. Again these formations must have been part of the inspiration for the dry stone greenhouse I designed to be built there and had the privilege to construct over two winter visits with a crew of competent wallers from the States and Canada and Wales We completed it last February.
The gables were built of flattish stones which are all laid at 45 degrees. These stones had to be perfectly square to the diagonal line of the sides of the triangle shape of the walls.
The stones lock tightly together using this style of construction, perhaps tighter than if they had been laid on the flat.
Even the outer stones along the diagonal ridge lock better than if they were stepped.
I suppose its because they all work like slightly leaning vertical copestones in a sense.
The trick is to build in diagonal rows and plan ahead so you can support a pre-chosen cornerstone exactly flush to the sloping plane of the sides and defined by the diagonal string lines.
