Cover completed brickwork and blockwork with polythene for 3 to 7 days depending on conditions to protect it from:

• Rapid drying out during hot weather and/or exposure to drying winds.

• Freezing and the chilling effect of cold winds.

In severe cold weather, an insulation quilt may be provided under the covering. Rain-soaked brickwork will be slow to dry, and this could lead to lime bloom (efflorescence). A robust and easy to read mercury thermometer is recommended for temperature measurement. Do not use frost-laden sand. Do not mix mortar when the air temperature is at or below 5˚C.