By: Jimmy Monohan Masonry
February 25th, 2022
Masonry Contractors typically experience a slow-down in work during the winter months. Once the spring arrives, Contractors have an opportunity to complete unfinished work from the prior construction season and get a fresh start in preparation for the construction season ahead.
Spring weather in NYC is unpredictable but is historically the wettest season of the year. We can experience large temperature swings in a short period of time; historical weather data indicates that temperatures have ranged between 12 degrees Fahrenheit and 97 degrees Fahrenheit. While we may not experience temperatures at these extremes during the spring, Contractors and Engineers should expect and be prepared to deal with hot and cold weather requirements for placement of masonry products with temperatures below 40AF and above 90AF.
Cold weather can have a negative impact on masonry systems and affect the overall performance, including the loss of strength and longevity of the system. These cold weather-related issues can be prevented with proper planning. In preparation for placement, masonry units should be stored in a heated environment. Water used for mixing should also be at a sufficient temperature to produce a mortar that is ideally between 60AF and 80AF. Additionally, mortar should be mixed in small amounts to prevent the mixture from cooling to a temperature below 60A. Finished masonry products must be protected with weather-resistive protection for 24 hours and the curing temperature of the masonry system must remain at 40AF or above during the curing period. Although it may not be necessary for the spring, Contractors and Engineers must consider the use of enclosures, forced air heaters and/or heated blankets for additional protection when there is a potential for temperatures to dip below freezing during the curing period.
Similarly, hot weather can have a negative impact on masonry systems and their overall performance. Some issues that Contractors have faced include reduced workability, reduced setting time, and masonry units absorbing more moisture from the mortar. Consequently, masons may find it more difficult to place mortar and masonry units, as heat may dry out the mortar, making it more difficult to spread. Proper planning will reduce the negative effects that hot weather can have on the finished masonry product. Some simple remedies include storing masonry products in the shade and away from direct sunlight, as well as scheduling brick installation during the morning hours when temperatures are cooler, and using cool water for mixing mortar. Mortar will absorb heat from mixers, wheelbarrows, and other metal surfaces that may be used for mixing. To prevent the rapid evaporation of water, metal surfaces should be wet prior to the placement of mortar into the mixer. A mortar with insufficient water will result in reduced bond strength in the masonry system, causing premature failure…