I always thought a 3/8 inch joint was fine for everything, but a job in Phoenix changed my mind.
We were building a big garden wall and I was using my usual 3/8 inch joint. My foreman, a guy named Ray, told me to switch to a 1/2 inch for the whole thing. I thought it would look sloppy, but with the heat out there, the bigger joint handled the expansion way better. After a year, my old walls would have cracks, but this one is still solid. Anyone else run into this with different climates?