Functional requirements of a Roof

•Strength and Stabilities

•Resistance to weather

•Durable and freedom from maintenance

•Fire Safety

•Resistance to the Passage of Heat

•Resistance to the Passage of Sound


The strength and Stability of a roof depends on;

• Characteristics of the Material from which it constructed

• The way in which the materials are formed as a horizontal platform or as a triangular framework.


Resistance to weather
•Smaller the unit of roof covering,such as tile or slate ,the greater must be the pitch or slope of the roof to exclude rain that runs down in the joints between the or slate on to the back of another tile or slate lapped under soon down the roof.

Durability and Freedom from Maintenance

The Durability of roof depends on;

•Ability of the roof covering to exclude rain, snow and the destructive action of frost and temperature fluctuation. Penetration of water into the roof structure may cause or encourage decay of timber, corrosion of steel or disintegration of concrete.

Resistance to the passage of heat

The very considerable disadvantage of the warm Roof is that as the insulation is directly under the roof covering,the material of the covering will suffer very considerable temperature fluctuations between hot sunny days and coldnights ,as the roof structure will absorb little if any of the heat or cold that the roof covering is subjected to.

•These very considerable temperature fluctuations will cause tar and bitumen covering such as asphalt and felt,become brittle and fail and cause severe mechanical strain in other covering

Resistance to the passage of sound

The mass of the material of a roof in the main consideration is the reduction of airborne sound.

A solid concrete roof will more effectively reduce air borne sound then a similar timber roof.



http://livinfo.blogspot.com/