Defects can arise in brickwork because of poor design or specification, the use of standard materials and non-technical workmanship at the design and construction stage. Following are the common problems and defects that similar to brickwork.
This is a common defect, at locations where the brickwork is exposed. The sulphate salts present in brick react with aluminium salts of cement. Due to the reaction, increase in the volume of mortar takes lace, which results in cracking, chipping and spalling of bricks. This may also cause failure of brickwork.
One of the most common and serious problems which can affect brickwork is uncontrolled water ingress. This can be a particular problem on exposed areas of a building such as upper floors and chimney stacks and in the vicinity of leaking rainwater pipes. Although a brick building may appear sound when viewed from ground level this may not be the case higher up on the wall face. Other areas at particular risk are parapets, areas surrounding downpipes and quoins (brickwork on the corner of a building). Once water has begun to penetrate brickwork it can quickly spread to affect a large area.
The following can be causes of water penetration and associated deterioration:
- Rising damp from subsurface moisture
- Windblown rain
- Condensation caused by lack of ventilation
- Failure of roof systems or rainwater goods
- Infiltration through failed mortar
- Inadequate surface drainage
- Encroaching vegetation
Corrosion of Iron and Steel
Exposed Iron and steel are corroded when they come in contract with water or moisture. The corrosion results in increased volume, which caused cracks in brick masonry.
Crystallization of Salts
Salts are a major cause of deterioration. Salt can enter bricks through contaminated water ingress. In coastal areas salt can come from the sea and, in winter, the nearby application of road salt is a constant threat. Salt is damaging because it creates a steady expansion of crystals within the bricks. This can eventually force the structure of the brick apart. The source of salt can occur from within the bricks themselves or from the application of contaminated mortars or renders. Brick lined chimney flues are also vulnerable as sulphates can be introduced when flu gasses condense. This is a common defect where a chimney has been sealed without adequate ventilation.
The volume of water is increased when it is frozen. Due to these phenomena, the cracks are caused in the brickwork. This defect is considerably reduced if the water accumulation is prevented.
Original Construction Defects
Sometimes brickwork was poorly constructed and defects inherent in the original construction can lead to later problems. Typical defects of this type are:
- Poor bonding between walls or into existing masonry where a brick addition has been executed.
- Poor quality bricks utilised (this is a particular problem with later mass produced bricks and those manufactured from colliery shale)
- Frog’ turned upside down to reduce mortar requirements.