If the mortar used for pointing brickwork is attacked by frost, it may become crumbly. Dig out all loose material to a depth of , about ½in/13mm, then re-point. You can buy bagged mortar mixes to which water is added.
Use the minimum of water to form a mix which just compresses in your hand and has the consistency of sand pies. Then dampen the gap to be filled with clean water a short time before work starts. This way, the mortar will not mark the face of the brickwork. Surplus mortar can be brushed away.
Should you get cement mortar on the brickwork, it can be removed by brushing with a special solvent. This is acidic, so be sure to protect your eyes and hands with a mask and gloves. It can also be used for cleaning your bricklaying tools.
To keep the dampness out of pointing, coat the wall with a silicone-based water-repellent. This will allow the wall to breathe but will prevent water from penetrating it.
