Principle for Supervision of Stone Masonry
The following principles should be followed during construction of stone masonry:
- The stone used in masonry should be durable and strong.
- All stones should be well watered before laying to avoid absorption of moisture from mortar.
- All stones should be properly dressed.
- The stones should be laid on their natural bed so that pressure acts normal to their bed.
- The different sized stones should be placed so that continuity of vertical joints is broken in the structure.
- The stones from opposite faces should make proper bond with each other.
- The height of stone should never be greater than their minimum horizontal dimension.
- Small stone chips should never be used in bed joints.
- Quoins should be laid as stretcher and header in alternate courses.
- Large flat stones used as bed plates should be provided under the ends of beams, girders etc.
- The hearting of the masonry should be properly packed with stone chips to avoid hollows.
- The upper surface of old structure must be cleaned before placing fresh mortar.
- The joints on the surface should be raked at least 2.5 cm deep and pointed with rich cement mortar.
- Double scaffolding should be used.
- After masonry is laid, it should be cured for a period of 2 to 3 weeks.