Specifications include, but are not limited to: Cutting technique shall be use if an air or electric grinder with a carbon or diamond blade and an air-chipping hammer and chisel. Contractor shall use a blade narrower than the joint and cut through the middle of the joint to a proper depth. The remainder of the material at the top and bottom of the joint shall then be carefully removed to avoid damage to the brick. A smaller blade shall be used to cut the vertical head joints to avoid damaging brick units above or below the head joints. In areas where joints cannot be cut to a proper depth as above, contractor shall use an air chipping hammer and chisel to finish cutting the joint to a proper depth to ensure a good bond of old and new mortar. All masonry surfaces shall be washed with pressurized water, approximately 1000 PSI. Where necessary to remove stubborn stains, a chemical cleaning agent shall be applied to the surface, allowed to dwell, and then rinsed in accordance with the manufacturer’s specifications. The chemical cleaning agents shall be applied no more than two times to any masonry surface. All mortar joints shall be carefully inspected and those found to have voids, cracks or openings greater than 1/64th inch in width or those found to be eroded more than ¼-inch in depth, shall be cut back to a depth of two times the joint width, but in no case deeper than 1-inch, and shall then be cleaned of all loose and foreign debris with air and/or water pressure.
