Steel

• Steel is a material strong in both compression & tension . It is also a stiff material 

•  Steel is economical because a small amount can carry a relatively large load . because it is stiff , the structure & its member will not easilyu deform under load 

•  These characteristics make it suitable for both low-rise & high rise building frames & roof structures of all spans . 

However steel in many circumstances requires the provision of fire-protection , such as encasement by concrete or asbestos board or protection by vermiculite or fire retardant paint .