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Fibre cement flat sheets are made of an inorganic hydraulic binder or a calcium silicate binder fanned by the chemical reaction of a calcareous and siliceous material reinforced by organic and inorganic synthetic fibers.
These sheets are used for external applications such as curtain walls, cladding facades, soffits, etc., and for internal use in partitions, ceilings, floors, etc. They may either have a smooth or textured surface.
Contents:
1. Types of Fibre Cement Flat Sheets
1.1 External sheets
They are intended for external applications where they may be subjected to the direct action of sun, rain, and snow. They may be supplied coated or uncoated.
1.2 Internal sheets
They are intended for internal applications and external applications where they will not be subjected to the direct action of sun, rain, and snow.
2. General Characteristics of Fibre Cement Flat Sheets
2.1 Length and Width
Flat fiber cement sheets shall be available in nominal lengths up to 3000 mm and nominal widths up to 1240 mm.
2.2 Thickness
Flat fiber cement sheets shall normally be available in thickness from 3 to 9 mm. The preferred thickness of sheets shall be 3, 4, 4.5, 5, 6, and 9 mm.
2.3 Tolerances on Dimensions
The tolerances on nominal dimensions shall be as follows:
2.3.1 For Length
- For Length up to 1000mm: ±5 mm
- Up to 1600 mm: ± 0.5% of L
- Above 1600mm: ±8 mm
2.3.2 For Thickness
- ≤ 6mm: ± 0.6 mm
- > 6mm: ± 10 %
- For sheets without texture on the exposed face, the maximum difference between extreme values of the thickness within one sheet shall not exceed 15% of the maximum measured value.
2.3.3 For Shape
- Straightness of edges: The tolerance on the straightness of edges shall be 3 mm/m for the relevant dimension (Length or width).
- Squareness of edges: The tolerance of the squareness of edges shall be 4 mm/m.
3. Types of Test carried on Fibre Cement Flat Sheet
- Bending strength
- Water impermeability
- Freeze-thaw
- Warm water
- Soak-dry
- Heat-rain test
3.1 Bending Strength
When the bending strength test is conducted in equilibrium and wet conditions, the average modulus of rupture of each piece of the finished products shall not be less than the values for the appropriate category specified in Table 1.
| Category | Modulus of Rupture, min (Mpa) | |
| External Sheet | Internal Sheet | |
| 1 | - | 4 |
| 2 | - | 7 |
| 3 | 7 | 10 |
| 4 | 13 | 16 |
| 5 | 18 | 2 |
The mean modulus of rupture under wet conditions must not be less than 50% of the mean modulus of rupture under equilibrium conditions.
The detailed procedure to conduct a bending strength test on fiber cement flat sheets is presented in the article:
Acceptance Tests on Fiber Cement Flat Sheets– Part-1 of 2
3.2 Water Impermeability
The traces of moisture may appear on the underside of the sheet during the water impermeability test, but in no instance shall there be the formation of drops of water.
The detailed procedure to conduct a water impermeability test on fiber cement flat sheets is presented in the article:
Acceptance Tests on Fiber Cement Flat Sheets– Part-1 of 2
3.3 Frost Resistance
For frost-resistant sheets, after 50 freeze-thaw cycles, the limit of the average ratio r shall not be less than 0.75.
The detailed procedure to conduct a frost resistance test on fiber cement flat sheets is given in the article below:
Acceptance Tests on Fiber Cement Flat Sheets– Part-1 of 2
3.4 Warm Water
The limit L shall be greater than 0.75.
The detailed procedure to conduct a warm water test on fiber cement flat sheets is given in the article below:
Acceptance Tests on Fiber Cement Flat Sheets– Part-2 of 2
3.5 Soak-Dry
The limit L shall be greater than 0.75.
The detailed procedure to conduct a dry soak test on fiber cement flat sheets is given in the article below:
Acceptance Tests on Fiber Cement Flat Sheets– Part-2 of 2
3.6 Heat-Rain
This test is carried out on the finished product. When sheets are tested, any visible cracks, delamination, or other defects shall not be of a degree affecting their performance in use.
The detailed procedure to conduct a heat-rain test on fiber cement flat sheets is presented in the article:
Acceptance Tests on Fiber Cement Flat Sheets– Part-2 of 2
Advantages of Fibre Cement Flat Sheets
- The fiber cement flat sheets are resistant to rust, rot, mold, moss, and algae.
- The fiber cement flat sheet structure has no risk of warping, shrinkage, or cracking due to thermal movement.
- These sheets have a life span of fifty years.
- Their durability makes these sheets highly robust, which require virtually no maintenance.
- These sheets enhance the ventilation levels in a building. When installed correctly, a fiber cement roof increases the crisp flow, improves a structure’s ability to breathe, and provides optimal ventilation.
- Fibre cement sheets are pretty easy to install.
- Fiber cement sheets are water-resistant.
- Fibre cement sheets offer good levels of acoustic insulation.
FAQs
Fibre cement flat sheets are made of an inorganic hydraulic binder or a calcium silicate hinder fanned by the chemical reaction of a calcareous and siliceous material reinforced by organic fibers and inorganic synthetic fibers.
Fiber cement flat sheets are used for external applications such as curtain walls, cladding facades, soffits, etc., and for internal use in partitions, ceilings, floors, etc.
The types of Test carried on Fibre Cement Flat Sheet are as follows:
1. Bending strength
2. Water impermeability
3. Freeze-thaw
4. Warm water
5. Soak-dry
6. Heat-rain test
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