Mine are going to be 16" and the motar thickness is to be about 12". I will place my logs closer than the one displayed and the log pieces are barkless and dried to lessen the expansion problem. The ends of my logs will extend 1 to 2 inches beyond the mortar. I like this look better. See following piece. This is a neat building when you do it right. Fits in to any wild look. The ones in Alaska had mostly rocks but they were uncomfortable to lean up against. Too hot. You also put sawdust in the mortar to allow for the expansion difference to lessen.
