Generally,we come across some old houses having roofs made with alternate series of asbestos sheets which are in wave shape.

House with reverse V shaped roof with corrugated asbestos sheets.

Corrugated Asbestos sheets

The advantage behind this design of sheets is that

From sunrise to noon whenever sun rays fall on one side of sheets,since these are opaque,they don’t let the rays pass through them.Hence,they create a shadow on the other side of corrugation(or wave).so,one side of corrugation will be hotter due to sunlight and the other will be cooler due to shadow.

*Similarly from noon to sunset,one side will be hotter and other will be cooler.

Thereby,it keeps the house cooler by considerable amount.

The other thing is that roof will be of inverted V shaped.(as shown below).

It also serves the same purpose as explained earlier.

Both the corrugated roof sheets and a reverse V shaped roof will maintain a cooler house than a flat one.(as shown below)

But, due to home requirements like water tank,pent houses etc.,. in modern houses,these designs are rare.

Hope it helps.

Thank you.