define roof

A roof is defined as a frame work of either timber steel or concrete on which  covering of thatch tile, corrugated, asbestos or any other materials of proper insulation is placed to protect the building from the adverse efect of rain, snow, sun and wind.

Functions of roof;

• to keep out rain, wind, slow and dust.
• to prevent exessive heat loss winter .
• to provide the interior of the building cool in summer.
• to provide safety to the occupants.
• to improve the appearance of the building.
• to provide resistance to the passage of sound inside the building.
• to provide strength, durability and stability for building

Requirement of a roof;

• should have adequate strength to carry the superimposed loads .
• should effeetively protect the building aginst sun, rain, wind etc.
• should be durable against the adverse effect.
• should be water proof and should have effeetive drainage arran....

A roof is defined as a frame work of either timber steel or concrete on which  covering of thatch tile, corrugated, asbestos or any other materials of proper insulation is placed to protect the building from the adverse efect of rain, snow, sun and wind.

Functions of roof;

• to keep out rain, wind, slow and dust.
• to prevent exessive heat loss winter .
• to provide the interior of the building cool in summer.
• to provide safety to the occupants.
• to improve the appearance of the building.
• to provide resistance to the passage of sound inside the building.
• to provide strength, durability and stability for building

Requirement of a roof;

• should have adequate strength to carry the superimposed loads .
• should effeetively protect the building aginst sun, rain, wind etc.
• should be durable against the adverse effect.
• should be water proof and should have effeetive drainage arrangements.
• should be fire resistant.
• should have adeqvate thermal insulation.
• should provide insulation against elternal sounds.

some technical terms associated with roofs;

Rise of roof

It is the vertical distance between the wall plate and the top of the ridge.

pitch of roof;

• the inclination of the sides of the roof to the horizontal is termed as pitch of the roof it is expressed either interms of degree (angle) or as a ratio of rise to span

span;

• the clear distance between the supports of an  arch, beam or roof truss is known as span.

eaves;

• lower end of the inclined roof surface of a pitched roof is termed as eaves 

ridge;

• Apex line of a sloping roof is known as ridge.

ridge piece;

• A member which runs horizontally at the highest level of the roof.

Hip;

• ridge formed by the interseetion of two sloped surfaces having an exterior angle greater than 180 degree.

valley;

• vally is the reverse of two roof surfaces making an exterior angle less than 180 degree.

hipped end ;

• sloped trangular surface formed at the end of a roof.

gable;

• a triangular portion of the end of a sloped roof formed by continuing the end wall up within the roof.

verge;

• Edge of the roof covering porjecting beyond the gable end of the sloped roof

common rafter;

• inclined wooden member laying from the ridges to the eaves.they are usually spaced  30 to 45 cm apart.

purlins;

• Horizontal members  of wood or steel used to support common rafters.

cleats;

• short section of wood or steel nailed screwed or bortid to the truss for supporting purlins.

Wall plates;

• usually 100 x 50 mm soft wood timbers fixed to the top of load bearing walsto distribute loads and provid fixing for roof timbers.

template;

• A block of stone or concret provid