Yes, bricklayers can work during the cold months, but it all depends on the type of work involved. For instance, residential housing maintenance works such as tuck pointing deficient mortar joints on exterior walls and columns as well as rebuilding of chimneys are best tackled during summer or simply put, the warmer months of the year. This is is mainly because the best results for these activities are achieved in the warmer months and several bricklayers will agree to this fact.
Mixing of mortar using anti-freeze technique to counter-act the effects of a cold weather can lead to white marks trailing down the brick when warmer temperatures comes knocking. As a result, even mortar mixing should be done at temperatures exceeding zero degree farenheit which will hold no serious consequences if the temperature should change to a little bit below the norms. During the winter, a good technique that can be incorporated to when mixing mortar would be to mix them in smaller quantities in a warmer environment. These small quantities will immediately be fed by the labourers to the bricklayers and in such circumstances, the mixed mortars will not be subjected to a freezing temperature for too long.
Generally, it would be very unwise to consider any bricklaying work to be done whenever the temperature jumps to a certain level which would be considered to be very inconvenient to work in. Interior works like remodelling of fireplaces can be tackled so long there is a warm space to mix the mortars while also keeping the materials at an indoor temperature. Bricklaying works that have, however, been completed during the colder months should be subjected to a very close inspection as well as looking for potential damage that can be caused to existing works as a result of the harsh weather.