Over the past 15 years chrysotile cement products have demonstrated some advantages over competitive building materials such as asbestos-free fiber-cement products and metal roofing.
Apart from its remarkable properties chrysotile cement has a better price and durability – its service life is 50 to 60 years and over. Besides, the use of local Portland cement helps save currency funds and labor costs. Their production is less energy-consuming. Taking into account all these factors we can conclude that chrysotile cement products have obvious environmental advantages over competitive products.
COMPARATIVE CHARACTERISTICS OF SOME ROOFING MATERIALS
|
N |
Characteristics |
Asbestos-cement sheets |
Corrugated galvanized iron sheets |
Aluminum sheets |
|
1 |
Service life |
50 (min) Stainless |
10-15 |
N/A |
|
2 |
Maintenance |
Not required |
Every 3-5 years |
Not required |
|
3 |
Fire danger |
Inhibitor |
Tend to distort and melt |
Tend to distort and melt |
|
4 |
Heat insulation |
Good |
Weak |
Weak |
|
5 |
Sound insulation |
Good |
Weak |
Weak |
|
6 |
Wind and rain-generated noise absorption |
Good (reduces the noise) |
Weak |
Weak |
|
7 |
Energy consumption required for manufacturing (kW.h/sq.meter) |
1.0 |
36.6 |
33.0 |
|
8 |
Potential work pressure |
Intensive |
Low |
Low |
|
9 |
Aerodynamic resistance after installation |
Good |
Weak |
Weak |
|
10 |
Weathering |
No |
Rusting of drilled holes and cracked zinc coating |
Oxidation of the surface |
|
11 |
Bimetallic reaction |
No |
No |
When contacting with concrete and other materials if wet |
|
12 |
Condensation |
Low, having no effect on the sheet |
High, leading to corrosion |
High, affecting the sheet |
|
13 |
Protective coating |
Not required |
Not required |
Necessary to prevent a direct contact with cement, lime, iron, copper, etc. |
|
14 |
Storage |
May be kept in the open in working areas |
Must be kept indoors to prevent weathering |
Must be kept indoors to prevent weathering |
|
15 |
Efficiency of coverage |
Almost 50 % higher than that of corrugated galvanized iron sheets and aluminum sheets |
The area coverage is only 67% of that with asbestos-cement sheets |
The area coverage is only 67% of that with asbestos-cement sheets |
|
16 |
Cost |
Low |
High |
High |
