Showerthought: a guy in Des Moines asked why I bead mortar on both faces and I still think about it
He was maybe 60, watching me lay a corner on a rental duplex job, and he just said "you're making twice the work for the same wall." I checked my joints at the end of that day and two of them had squeezed out hollow, so he was right and I switched to one face on block and never went back. Anybody else get corrected by a total stranger mid-lay like that?