Why Are Asbestos Sheets Used for Roofing Corrugated?

[pukb]

The asbestos sheets sometimes used for roofing, to avoid sunlight in front of stores etc, are always corrugated. Can somebody explain why these sheets are corrugated and not flat.

 

[Bavid]

First, I have seen flat asbestos sheets at places, so the corrugated shape must be based on utility, rather than a fabrication limitation.

I'd imagine corrugated sheets are much more efficient at diverting dirt and rainwater from inclined roofing. If you had flat sheets, they might suffer unpredictable warpage.

Corrugated sheets also interlock easily, thereby making waterproofing possible.

 

[JizzaDaMan]

I would also have thought that corrugated sheets are much stronger than flat sheets

 

[Chestermiller]

Corrugated sheets have higher bending stiffness than flat sheets (at least in certain directions) because of the higher moment of inertia.

 

[enosis_]

Where are these materials used?

 

[pukb]

I agree that corrugated sheets have a higher area moment of inertia and hence a higher bending stiffness. But why is asbestos generally used there?
Is it because it is a good thermal resistor?

 

[Chestermiller]

Use of asbestos is no longer practiced because of the health hazzards. Back in the day, it was often used as a thermal insulator.

 

[enosis_]

Please clarify - are corrugated asbestos sheets being used for new construction somewhere or not?

 

[AlephZero]

Please clarify - are corrugated asbestos sheets being used for new construction somewhere or not?

See http://en.wikipedia.org/wiki/Asbestos#Asbestos_in_construction

 

[enosis_]

See http://en.wikipedia.org/wiki/Asbestos#Asbestos_in_construction

From your link...

"Asbestos construction in developing countries
Some countries, such as India, China, Russia and Brazil have continued widespread use of asbestos. The most common is corrugated asbestos-cement sheets or "A/C Sheets" for roofing and for side walls. Millions of homes, factories, schools or sheds and shelters continue to use asbestos. Cutting these sheets to size and drilling holes to receive 'J' bolts to help secure the sheets to roof framing is done on-site. There has been no significant change in production and use of A/C Sheets in developing countries following the widespread restrictions in developed nations[citation needed]."