875—91.8 (89) Alterations, retrofits and repairs to objects.
	 91.8(1) General. Alterations, retrofits, and repairs shall be made so that the object shall be at least as safe as the original construction. Alterations, retrofits, and repairs shall be done as though new construction and shall comply with the applicable code or codes as adopted in 875—Chapters 90 through 96. A National Board “R” form shall be filed with the division for each alteration, retrofit, or repair.
	 91.8(2) Lap seam cracks. The shell or drum of an object in which a lap seam crack is discovered along a longitudinal, riveted joint shall be immediately discontinued from use. If the object is not more than 15 years of age, a complete new course of the original thickness may be installed at the discretion of the inspector. Patching is prohibited.