ASTM C270, ASTM C1324, ACI 530, TMS 0402, NPS Preservation Brief No. 2, BIA Technical Notes, OSHA 29 CFR 1926.1153 (silica), Secretary of Interior's Standards

• Systematic visual inspection and hammer sounding of all masonry surfaces; document delaminated and deteriorated areas.
• Photograph all deficiencies; produce deficiency map on elevation drawings.
• Probe all mortar joints to assess bond and depth; expose representative wall ties to check corrosion.
• Classify deficiencies: Immediate Hazard / Critical / Moderate / Minor.

• Collect existing mortar samples from minimum 3 locations per facade face.
• For historic masonry: submit samples for lab analysis per ASTM C1324.
• Produce cured mortar color chips for Owner approval.
• CRITICAL: replacement mortar must never exceed compressive strength of masonry units.

• Type N (750 psi): above-grade exterior — most common for repointing.
• Type S (1,800 psi): below-grade, structural CMU, foundations.
• Type O (350 psi): historic pre-1900 brick, soft stone.
• NHL 3.5/5: historic and landmark — no Portland cement; SHPO-grade.
• Lime putty: pre-1900 brick; SHPO Grade A restoration.

• Minimum removal depth: 3/4 inch from face — no feathered edges; no face-pointing.
• Hand chisel required on all historic masonry, stone, terra cotta, and joints narrower than 3/8".
• OSHA 1926.1153 silica: HEPA vacuum at all power tools; wet suppression; respiratory protection mandatory.

• Pre-wet joint faces to SSD condition before applying mortar.
• Pack in maximum 3/8" lifts; allow each lift to reach thumbprint hardness.
• Tool joints to match original profile (concave preferred; no raked joints on exterior).
• Mist freshly tooled joints 2–3 times daily for 3 days; protect from direct sun, wind, rain, and freezing.