If old bricks get damp and the water freezes, it expands and pushes off their outer surface.
If no action is taken the bricks eventually disintegrate completely, though some types of brick are more susceptible to this than others.
If the surface of the brick is only slightly damaged, a reasonably invisible repair can be made by patching with mortar coloured to match the surrounding bricks.
If you do this, you must be careful not to cover over the surrounding mortar.
To get the correct colour, you can start by experimenting with a concrete colourant.
If you can't get a close enough match, buy a brick of the same type and using a club hammer pound it into small pieces.
(Make sure you wear goggles while you do this to prevent brick chip-pings flying into your eyes.
) 1.
Next, mix the brick dust with some ready-mix bricklaying mortar.
Mix up with water and add a little PVA bonding agent.
Make sure the surface of the damaged brick is free of any dust or particles of flaking bricks, then coat the exposed face with a light layer of dilute PVA adhesive which helps the mortar to adhere.
Before you apply the mortar, cover the existing pointing with a thin piece of wood, held in place temporarily.
2.
Applythe mortar overthe surface of the brick, until it is level with the surrounding brickwork.
When the mortar is first applied, it will be considerably darker than the surrounding bricks.
However, once it dries out, it will become lighter and blend in with the rest of the walk If the surrounding bricks are old and irregularly shaped, don't make the edges of the damaged brick too perfect.
If the damage is more extensive then rather than trying to patch the damaged brick, it would be better to replace it with a matching one.