Tips and advice

The method applied to the external restoration of a building is illustrated below:

STAGE 1	Remove existing mortar
STAGE 2	Repairs to building fabric
STAGE 3	Clean building fabric
STAGE 4	Seal building fabric
STAGE 5	Repoing elevations

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.





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





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 facade. The use of water also activates the dormant lime within the existing mortar, which will provide the appropriate required bond with the pointing.





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.





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.

Obsolescence of building fabric

Example A illustrates the failure of the pointing element of the construction. Water ingress and frost damage has caused severe shelling to the face of the construction materials. Due to the failure to address the pointing obsolescence, costly reconstruction is now required. This stage of obsolescence affects factors such as property value, marketability and general perception of maintenance with financial implications for the building owner.

Example B illustrates a section of elevation from a late 1980’s building. At the time of construction a raked out finish was specified for short-term aesthetic purposes. Unfortunately, this approach has resulted in water ingress and the build up of moisture within the building fabric; subsequently the longevity of the building is seriously undermined. This common example highlights the current difficulties faced by both building owners and the construction industry. The absence of contractors with the appropriate skills to provide a quality finish to the pointing element means that new-build specification of this type will continue despite the obvious implications.
Risk - Poor quality workmanship

Examples C and D illustrate sections of two elevations immediately after repointing works has been carried out. There are a number of obvious problems associated with the quality of workmanship.

Firstly, the composition of the mortar is of building sand and Portland cement, which is likely to affect the long-term performance of the pointing due to the absence of lime that is required to form the correct bond with the original mortar.

Secondly, the mortar has been prepared without a consistent form of measurement, indicated by the array of different colours.

Thirdly, the staining of the brick face during the preparation stage indicates the elevations were not cleaned and, subsequently, the original dormant lime not reactivated.

Finally, the quality of the cut of the pointing is poor, resulting in the perception of uneven brickwork.