The given figure represents a dog spike. It is U-shaped and has pointed ends. It is usually made up of wrought iron.

The manually operated alarms should be provided near all main exits and in natural path of escape from fire and at readily accessible points which are not likely to be obstructed by smoke. It is of utmost important to make suitable arrangement to protect opening in case of a fire.

Dogs maybe flat or circular. The ends of dogs are appointed so as to facilitate driving into timber. Dogs can be imagined as a channel section with sharpen ends.

Cast iron files into pieces when heated and suddenly cooled. Hence, when this material is used in construction, it is covered eir by brick work of one brick thickness or any or fire resisting material such as concrete.

Whereas, a clout nail has large, flat, circular ahead. Lath nail has a square and tapering shank with rough sides. Trenail is a pin of hard wood and can be used in pieces of Iron nails where it is feared that Iron nails would rust and injuries timber.

The possibility of loss or damage to life is referred to as personal hazard and naturally it is not permanent importance. The fire safety provisions would be liberally provided for this type of hazard and safe fireproof exist should be suitably accommodated in division of building having more than one storey.

Nosing term has a slightly different meaning when used in relation to step of a Stair. A rounded Nosing has overhanging edge semi-circular in section.

Angle joints are very often secured by nailing and glue is used for making se joints. Butt joint, Rebated butt Joint, Tongues joint, Housed joints, etc are some examples of this type of joint.

Lengning joints are also known as spliced or longitudinal joints. The method of lengning will depend on situation of member in a frame structure where such joints are commonly required.

The concrete offers a much higher resistance to a fire than any or material. The actual behaviour of concrete in case of fire depends on quality of cement and type of aggregate forming concrete and in case of reinforced and pre stressed structure, it also depends on position of Steel in concrete.