Friday, February 05, 2016

Brickwork Specifications

  • Inadequate soaking of bricks.
  • Strength of brick less than specified.
  • Thickness of joint exceeds 1 cm.
  • Expansion joint not provided.
  • Parapet walls of balconies, landing and staircases are constructed with 7 cms thick brick masonry, in cement mortar. This is an unsafe method as the walls are likely to collapse, due to horizontal force. In these cases, it is necessary to reinforce them. 

 Following steps needs to taken out to avoid defects in brick work:

 

  • Bricks required for brickwork shall be adequately soaked in stacks before use by spraying with clean water at regular intervals for a period of not less than 6 hrs before use so as to keep them wet.
  • Vertical joints in alternate courses shall come directly one above the other.
  • Work done per day should not be more than 1 m.
  • Horizontal runs of water supply pipes should be avoided in masonry walls.
  • Sometimes, holes are punctured in the staircase walls to support the landing slabs to accommodate the beam over which staircase beam rests. Before doing this, the resisting capacity of brickwork should be checked.
  • Sometimes, openings are made temporarily in load bearing walls to use as entrance from one room to another. This reduces the strength of the wall due to the reduction of the wall area designed for. In case, openings are to be made, the strength of brickwork to resist the load at the bearing is to be checked.
  • Top course of plinth, parapet, steps and top wall not provided with brick on edge.
  • While plastering, joints in masonry works should be racked to provide a good key between plaster and masonry.
  • Whenever masonry partitions have length to height ratio higher than two, horizontal reinforcement is to be provided in the masonry.
  • If sulphate content in soil exceed 0.2% or in ground water exceeds 300ppm, it will attack various components of the building. To prevent this, sulphate resisting cement is used.

Specifications for Bricks:

  • Size of brick should be 9" * 4.5" * 2.75" or (20* 10 *10 cm).
  • Brick should be free from cracks and nodules of free lime.
  • It should be tested for:
  • Compressive  strength.
  • Water adsorption.
  • Efflorescence.
  • Dimension.