“But the older ones can require maintenance or repair too, especially if driven into by a passing car (as happened at Easton in 2013). Due to the cost of a proper repair, some don’t survive.”
Crinkle crankle connoisseur Ed added that the advantages of serpentine walls are that they use fewer bricks, are ideal ‘hot walls’ for growing soft fruit in the concave alcoves, and give you “bragging rights over your neighbor!”
They're called wythes, not layers.
But that's none of my business.