The method applied to the external restoration of a building is illustrated below.
Stage 1 The decayed mortar is raked out using traditional
hand tools to approximately twice the width of the mortar joint. The traditional
method is preferable to mechanical techniques such as angle grinders due
to unavoidable damage of cuts to the brickwork and staining from lime
dust.
Stage 2 It is highly probable that a percentage of the brickwork has suffered from varying degrees of failure. The repairs are performed using various techniques:
- If damage is severe, brickwork is replaced using the appropriate match
- If damage is minor, the brickwork is cut out and the reverse side utilised
- When damage is superficial, a colour-matched repair paste is applied
Stage 3 The building is cleaned traditionally by hand with water, brushes and carborundum stones. Corrosive chemicals and pressure-washing equipment are not used to avoid irreparable damage to the façade. The use of water also activates the dormant lime within the existing mortar, which will provide the appropriate required bond with the pointing.
Stage 4 A light cement wash of the appropriate colour is applied to seal the brick face and protect the building from water and frost damage. Chemical sealants are avoided so to prevent trapping residue water within brickwork and preventing the building fabric from breathing.
Stage 5 The final stage of repointing is performed using
bespoke hand tools specifically designed for achieving the
correct original weather-struck and cut joint, which require individual
manufacture. The mortar used consists of
sharp sand – which is sieved by hand – lime and minimal quantities
of portland cement. Chemical additives and portland cements are generally
avoided due to the appropriate bond that is achieved through the lime
content. Chemical additives and today’s cements have the reverse
affects required with the pointing, failing to make the required bond
with the original lime mortar.
Before 
Stage 1 
Stage 2
Stage 3
Stages 4 and 5