I am adding a front to my fireplace and I am wanting to attach seashells to it. I have been told to use Mastic as an adheasive. I have also wondered if I should use stucco or thin set. any advise on which works best. They are larger shells(a little heavy) and I dont' want they material to chip off. thanks
Dont use mastic around a fireplace. It will turn brittle if the heat gets to it causing the pieces to fall off the wall or at least sit there with only the grout holding them in place.