I'm having a wood burning stove put into my fireplace, which I opened out. The stove is 17" wide, the opening is 23" wide. The walls are plastered to the edge of the opening. How likely is it that the plaster will crack due to the heat? I haven't measured the temperature of the air around a stove, but it is fine to place a hand above the stove. A plasterer said it would likely crack, and he could fireboard around the fireplace, and blend in with the wall plaster.