1. Seminar on roofs and slabs
--SANTHOSHKUMAR.M

2. WHAT IS ROOF?
A roof of a building envelope, both the covering on the uppermost part of a building or shelter.
Provides protection from animals and weather, notably rain, but also heat, wind and sunlight; and the framing or structure which supports the covering.
Purpose of the roof may vary according to places and situations.

3. Classified based on Material: Construction:
It may start from banana leaves , straw ,sea grass , laminated glass, metal plates to now a days precast concrete.
Construction:
It’s determined by it’s method of support needed or whether the roof is pitched.
Pitch:-The pitch is the angle at which the roof rises from its lowest to highest point.
Most US domestic architecture, except in very dry regions, has roofs that are sloped, or pitched.
Although modern construction elements such as drainpipes may remove the need for pitch, roofs are pitched for reasons of tradition and aesthetics.

4. Durability:
life time of a roof is a matter of concern because the roof is often the least accessible part of a building for purposes of repair and renewal, while its damage or destruction can have serious effects.

5. Parts of roof:
Supporting structure
Outer skin or weather proof layer

6. Supporting structure:
The supporting structure of a roof usually comprises beams that are long and of strong, fairly rigid material such as timber, cast iron or steel(19 cent.).
In countries that use bamboo extensively, the flexibility of the material causes a distinctive curving line to the roof.

7. Outer skin (or) layer:
This part of the roof shows great variation dependent upon availability of material.
In vernacular architecture, roofing material is often vegetation, such as thatches, the most durable being sea grass with a life of perhaps 40 years.
The 20th century saw the manufacture of composition asphalt shingles which can last from a thin 20-year.

8. A slate roof may last 75 to 150 years, and even longer.
Slate is an ideal, and durable material. The slate roof is often considered the best type of roofing.
A slate roof may last 75 to 150 years, and even longer.
Asbestos, usually in bonded corrugated panels, has been used widely in the 20th century as an inexpensive, non-flammable roofing material with excellent insulating properties.
But due to health issues and mining issues made it no longer used as new roofing material.
However it continues to exist in south america and asia.

9. Function:
Purpose of roof is to isolate the people and their belongingness from climatic conditions.
Some roofing materials, particularly those of natural fibrous material, such as thatch, have excellent insulating properties.

10. Thank u “be focussed your goals are high…”