Correct procedures for repointing brickwork?

Repointing or tuck-pointing existing brickwork may be in order when mortar joints have softened, deteriorated or exhibited pronounced cracking. Generally, repointing involves carefully removing existing damaged mortar while not disturbing or cutting the existing brick. The joint is then repacked with mortar in layers.It is important to remember that the mortar should always have slightly less strength than the brick. Usually, the best mortar for use in repointing is what was in the wall to begin with. For most walls less than 70 years old, generally Type N or O mortar should be used when repointing. For structures older than this, it is best to try and determine what the original mortar consisted of and match that.