Corrugated Metal Roof for Wooden House Construction
Most of the wooden houses in West Papua are now using corrugated metal roof called "seng" or zinc (Zn) This type of roof is very popular not only in West Papua but also in Indonesian and even all over the world. In the past, Papuan people usually use sago palm leaves as the roof cover for their houses. These leaves can only be used for 2 years. They have to be replaced Although the corrugated metal roof is called zinc, actually it is made of layers of iron, aluminum and zinc. The zinc metal roof has a range of thicknesses from 0.2 to 3.8 milimeters. There are some possible combination that we can find in corrugated metal roof that we usually find in the housing materials shop in Indonesia:
Fe coated by seng = 1.50%
Pb coated with seng = 0.90%
Al coated with seng = 97,25%
Zn coated with seng = 97.25%
I got the chemical compositions of the corrugated metal roof from this website: http://www.adimas.co.id/ind/senggalvanis.htm
Another material that is now getting more attention from home builders is Zincalume G-550. It is alloyed steel plate protected with metal layers whose composition is 55% aluminum and 45% seng. This is Zincalume layer is twice up to six times more resistant to corrosion that other galvanic steel plate for similar application as roof deck. When there is a fire in a wooden house, the chemical composition of the metal roof plates change significantly due to overheating. As a result they cannot be used for rebuilding the house anymore.