Choosing the right roofing material is a crucial decision for any construction project, especially in Bali where the climate and local aesthetics play a significant role. This guide explores various low-cost roofing options available, considering factors like durability, cost-effectiveness, and suitability for the Balinese environment.
Understanding the Basics
Before diving into specific materials, it’s important to understand a few key considerations:
- Roof Pitch: A roof’s slope is critical for water runoff. Materials like roof tiles, alang alang (thatch), and shingles require a pitch of at least 36 degrees to prevent rainwater from being driven into the roof by the wind. Corrugated sheets are more suitable for gently pitched roofs as they allow for greater overlap.
- Material Quality: The quality of materials directly impacts longevity. For example, low-grade clay tiles, handmade and fired in local kilns, are often porous, break easily, and don’t fit well together.
Low-Cost Roofing Materials
Here’s a breakdown of affordable roofing options commonly found in Bali:
- Corrugated Asbestos: While being one of the most affordable options, the use of asbestos is not recommended due to its health risks. Asbestos fibers, if inhaled, can lead to serious conditions like mesothelioma. While painted asbestos panels are relatively safe, cutting or breaking them is dangerous.
- Corrugated Clear Fibreglass: This is a very low-cost option, however, it deteriorates quickly in sunlight. UV light exposure makes it brittle and prone to cracking.
- Corrugated Zincalume: Made from steel coated with a zinc-aluminum alloy to prevent rust, this material is a relatively affordable option. However, modern versions are often thin and easily dented. It can also be very noisy during rain and hot under the midday sun.
- Cladian Corrugated Plastic: This low-cost material is effective but may discolor with prolonged sun exposure.
- Low-Cost Clay Tiles: These tiles are made from local clay and fired in wood kilns, they are low cost but also lower quality. They are often porous, fragile, and don’t fit well together. Higher quality glazed tiles are available, which require higher temperatures to fuse the glaze, resulting in a much stronger tile.
- Low-Grade Alang Alang: Alang alang, a type of thatch made from local grass, is another low-cost option. However, the quality of alang alang has declined, with modern versions often lasting only 5 to 8 years due to the use of fertilizers that reduce the quality of the grass. The density of the grass and the thickness of the roof vary with quality, and the bearers underneath should be closely spaced on a high-quality roof.
- Onduline: This corrugated bituminous sheet is a useful replacement for asbestos, but it is not a cheap option.
Other Roofing Materials
While not the lowest cost, here are a few other materials to consider:
- Ironwood Shingles: These are an aesthetically pleasing alternative to alang alang. Proper installation with sufficient layers and correct overlapping is needed to prevent leaks, especially at roof ridges.
- Polycarbonate Roofing: Popular for carports and pergolas, it can be stylish but is not cheap and often leaks due to improper installation.
- Bamboo Shingles: These are available, but information about them is limited.
Unconventional and Temporary Options
- Cardboard Boxes: While they provide warmth and comfort, they are not suitable for wet conditions.
- Banana Leaves: These can be used as a free temporary solution.
Conclusion
Choosing a roofing material is an important step in any construction project. While low-cost options are available, it’s essential to consider factors like durability, safety, and suitability for the local climate. By understanding the strengths and weaknesses of each material, you can make an informed decision that balances cost with long-term performance.
