To fill up the gap between a nail and a nail hole and prevent water from penetrating and spreading to the back of a plate by covering the circumference of the back of a nail head and a part or the whole of a nail neck with a water swelling wettability resin and using the nail for fitting and fixing a ceramic facing material.

A nail 1 is made of a metal material such as steel, stainless steel or aluminum, and the circumference of the back of a head 11 of the nail 1 and part or the whole of a neck 12 are covered with a water swelling wettability resin such as an acrylate or a starch. The nail 1 is used fitting and fixing a ceramic facing material. Thus when a plate such as a ceramic facing material is fitted and fixed to the bed of a building body column, the water swelling wettability resin comes in contact with the water, quickly sucks it, swells up even if water penetrates through the nail hole, blocks the gap between the nail 1 and the nail hole, and can prevent water from penetrating and spreading to the back of the plate.