STONE MASONRY

It is the art of building a structure with stones. The selection of material depends on the following:

Table Showing Different Stones Used for Different Purposes

Purpose	Stone used
Heavy engineering works like dock, breakwater, lighthouse, bridges, etc.	Granite and gneiss
Buildings situated in industrial towns	Granite and compact sandstone
Pavements and railway	Granite and basalt
Electrical switchboards	Marble slab and slate
Fire resistance works	Sandstone
Carving and ornamental works	Granite and marble

The general principles in stone masonry construction are as follows:

The stones to be used for stone masonry should be hard, tough and durable.
The pressure acting on stones should be vertical. The pressure acting along the direction of bedding planes causes splitting of stones.
The stones should be properly dressed as per the requirement.
The headers and bond stones should not be of a dumb-bell shape.
In order to obtain uniform distribution of load, under the ends of girders, roof trusses, etc. large stones should be used.
The beds of the stones and the plan of the courses should be at right angles to the slope in the case of sloping retaining walls.
Wood boxing should be fitted into walls having fine dressed stonework to protect it during further construction.
The mortar to be used should be of good quality and in the specified proportion.
The construction work of stone masonry should be raised uniformly.
Plumb bob should be used to check the verticality of erected walls. In addition, wooden templates should be used to check the battered faces.
The stone masonry section should always be designed to take compression and not the tensile stresses.
The masonry work should be properly cured after the completion of work for a period of 2-3 weeks.
As far as possible, broken stones or small chips should not be used.
Double scaffolding should be used for working at higher levels.
Properly wetted stones should be used along with mortar for construction work.

STONE MASONRY