A method and apparatus for avoidance of damage to concealed mechanical elements during construction or repair of a structure. In one embodiment, a tag is provided for installation on a plumbing or similar element prior to such element being concealed by further construction. The tag is adapted to engage a concealed element in such a way that an indicator portion of the tab remains visible after further concealing structure is installed. The visible tab's location identifies the location of concealed elements and is preferably provided with indicia identifying such purpose. In a further embodiment of the invention, adhesive indicator tape is used in conjunction with an indicator tab. The indicator tape is adapted to be applied over concealing structure to generally identify the location and extent of concealed elements that may be susceptible to puncture or damage during subsequent construction or repair phases of a project.