MAINTENANCE OF BRICKWORK

Cracks are frequently found in brick masonry wall. Causes for such cracks have been discussed in Section 17.2. It has been discussed that prevention of cracks in brick masonry may be avoided by proper foundation design and providing different joints such as expansion joints, isolation joints, sliding joints, etc.

Maintenance of brickwork involves in cleaning, removal of efflorescence, repairing of cracks, re-painting brickwork and re-painting old brick joints.

Cleaning Brickwork

Brickwork has to be cleaned with steam or steam and hot water jets. This treatment is suitable for fine-textured and hard-burnt bricks. Sand blasting can also be done. However, this disturbs the texture of the bricks and absorbs the painting.

Removal of Efflorescence in Brickwork

Soluble salts after drying get deposited on the surface of the walls as white layer. These salts may be present in the material of the walls and come out. Sources of these salts are mortars and plasters. As moisture is the cause for the creation of efflorescence, this can be checked by proper damp prevention.

Efflorescence can be removed by scrubbing those portions on the wall with water and a tough brush. For effective use instead of water, 10% of solution of muriatic acid may be used. After this treatment, the wall has to be rinsed with clean water or with a weak ammonia solution.

Repairing of Cracks in Brickwork

Cracks in brickwork are rectified by adopting the following procedure:

1. If the cracks are less than 1.5 mm in width, the cracks may be filled with commercially available putty.
2. Wider cracks are repaired by releasing them out to about 25 mm and re-filling with 1 cement, 2 lime, 9 sand mortar or any crack-filling material available in the market.
3. Still wider cracks may have to be stitched by using reinforced mortar or concrete stitching blocks.

Re-pointing Old Brickwork

In the case of brickwork which are pointed may be needed to re-point in order to improve the appearance and to make it water tight. Generally mortar at the pointed portions gets lost due to rain, wind, freezing, etc. Following procedure may be followed for re-pointing:

1. The joint of the old mortar is loosened and scrapped out and cleaned for a depth of at least 3 mm and wetted with water.
2. New mortar is applied to the joints with special trowel and pointed as per practice.

Re-painting Brickwork

Re-painting is necessary for walls which have been previously painted. The type of paint and colour should be decided and accordingly the surface has to be prepared.