Apply cold-weather mortar rules for masonry repair and repointing work, scheduling around temperature thresholds

Steps

1. Confirm the applicable cold-weather threshold: per masonry industry cold-weather construction guidance (e.g., International Masonry Institute materials), cold-weather precautions apply once ambient temperature is 40°F and below
2. In the 40°F to 32°F range, heat either the mixing sand or the mixing water (not necessarily both) to bring mortar temperature into the target range (commonly cited as roughly 40-120°F) at the time of placement
3. In the sub-32°F to 25°F range, heat both the sand and the water to reach the same mortar temperature target, since a single heated ingredient is no longer sufficient
4. Below 25°F to 20°F, in addition to heating both materials, ensure the masonry surface being worked on is at least 40°F and provide wind breaks or enclosures whenever wind speed exceeds roughly 15 mph
5. Below 20°F, do not lay masonry without a heated enclosure, and never lay units that have visible ice or snow on them or that are themselves at or below roughly 20°F
6. Protect newly placed mortar from freezing for the appropriate period after placement (commonly at least 24 hours for ungrouted work, longer for grouted work depending on cement type and forecast low temperatures) using insulating blankets or enclosures, and verify current specific thresholds against the latest published cold-weather masonry construction guidance before finalizing a project's cold-weather plan