The 3 Best Roofing for Rainwater Collection

As water scarcity becomes an increasing concern worldwide, the significance of rainwater collection systems is gaining momentum. Rainwater harvesting not only provides a sustainable water source but also reduces reliance on municipal water supplies.

This method involves the collection of rainwater from catchment areas, such as roofs, and its subsequent storage for later use. The quality of the collected rainwater is highly dependent on the type of roofing material used.

It’s essential to choose roofing that doesn’t contaminate the water, especially if it’s intended for drinking purposes. Therefore, understanding what constitutes the best roofing for rainwater collection is crucial to optimizing this eco-friendly practice.

Impact of Roof Types on Harvesting Rainwater

Asphalt Shingles

Asphalt shingles, a common type, can affect rainwater collection. They often shed granules, which contaminate the water. They may contain toxic chemicals that leach into the water.

• Pros: Affordable and easy to install.

• Cons: Potential contamination and reduced water quality.

Metal Roofs

Metal roofs are an excellent type for rainwater collection. They provide a smooth surface for efficient runoff and minimal contamination.

• Pros: High-quality water collection; long-lasting.

• Cons: Higher installation cost.

Tile Roofs

Tile roofs, another type, offer durability but may contribute to alkaline rainwater due to their material composition.

• Pros: Durable and aesthetically pleasing.

• Cons: Alters the pH level of collected water.

Green Roofs

Green roofs incorporate vegetation, impacting the quality and quantity of harvested rainwater. The soil and plants can filter pollutants but also introduce organic matter into the system.

• Pros: Natural filtration system.

• Cons: Reduced volume of harvestable water; potential organic contamination.

3 Best Roofing Materials for Rainwater Collection

Metal Roofs

Metal roofs top the list of preferred roofing materials for rainwater collection. They’re durable, easy to maintain, and offer a smooth surface for water runoff.

• Aluminum: Lightweight and rust-resistant

• Steel: Strong and long-lasting

Asphalt Shingles

Asphalt is a safe and stable material for collecting rainwater. However, it’s worth noting that the adhesives used for installation can release gases during the first few years.

If you have a newly installed asphalt shingle roof, it’s best to avoid watering edible plants for the first few years until the off-gassing is complete.

• Organic shingles: Made from recycled felt paper

• Fiberglass shingles: More fire-resistant than organic ones

Clay Tiles

Clay tiles are another viable option. While they may not collect as much water due to their rough texture, they are environmentally friendly.

• Terracotta tiles: Fired at high temperatures for durability

• Concrete tiles: Cheaper alternative to terracotta

Remember that the type of roofing material can significantly impact the quality of the collected rainwater. Therefore, it’s essential to choose wisely based on your specific needs and local climate conditions.

Risks of Incompatible Roof Surfaces

Surface Material Matters

The best roofing for rainwater collection demands careful consideration of the surface material. Not all roof surfaces are suitable for this purpose:

• Asphalt shingles may leach harmful chemicals into the water.

• Metal roofs, while durable, can be problematic if they’re coated with substances that might contaminate the water.

• Clay or concrete tiles are generally safe but could break under heavy rainfall.

Contamination Risk

The risk of contamination is a significant concern with incompatible roof surfaces. For example:

1. Bird droppings on the roof can contaminate collected rainwater.

2. Leaves and other debris could cause blockages in the collection system.

3. Airborne pollutants can settle on the roof and mix with rainwater.

Roofing Age and Condition

Roofing age and condition also play a part in rainwater collection:

• Older roofs may have worn-out materials that can affect water quality.

• Damaged roofs might not efficiently channel water to your collection system.

Role of Metal Roofs in Collection

Metal roofs play a significant role in rainwater collection. They are ideal for this purpose due to their smooth, hard surfaces.

Types of Metal Roofs

Different types of metal roofs can be used for rainwater collection:

• Enameled metal roofs: These have a durable and glossy finish that aids in water collection.

• Steel roofs: Known for their strength and durability, they provide long-term efficiency in rainwater collection.

The material choice impacts the quality and quantity of the collected water. Enameled metal and steel are popular choices due to their longevity and resistance to weather conditions.

Maintenance Tips

Proper maintenance is key to optimizing a metal roof’s performance in rainwater collection:

• Regular cleaning: This prevents debris accumulation, which can affect water quality.

• Inspection: Regularly check for signs of wear or damage that could impact efficiency.

Materials to Avoid

When choosing materials for rainwater collection, it is crucial to avoid certain types. Some materials can cause debris or even contaminate the water.

Certain roofing materials may not be suitable for rainwater harvesting. It’s important to be aware of them. Here’s a short list of materials to be cautious about:

1. Cedar Shake: These are wooden shingles that are usually treated with fire retardants. It’s advisable to test a sample to make sure you’re comfortable with it in your water. This water might be suitable for watering plants.

2. Copper: Copper roofs, while luxurious, have a natural resistance to the growth of algae and moss because copper acts as an herbicide. However, it’s worth noting that copper can seep into your rainwater. If you plan to use the harvested water for garden irrigation, copper might not be the best choice.

3. Lead: In certain parts of the USA, lead flashing is still used. If you’re collecting rainwater for drinking purposes, it’s crucial to test for lead.

4. Biocides: Some rooftops are treated with substances known as biocides. Shingles treated with zinc or copper are common in the Pacific Northwest to prevent the growth of mold, moss, and algae on the roof. If you’re harvesting rainwater for irrigation, ensure that the levels of biocides are low enough not to harm your plants. You can check where your downspouts drain onto the existing landscape to get an idea of whether biocides are concentrated enough to potentially harm the grass or other plants in that area.

Being mindful of these materials will help ensure the quality and safety of the harvested rainwater.

Roof Coatings

Roof coatings play a crucial role in rainwater collection. A special kind of roof coating made to collect rainwater is called elastomeric paint.

This is a choice worth considering, especially for roofs that might not otherwise be safe for water collection because they may be more expensive and typically require several layers.

For systems that collect rainwater for drinking, the National Sanitation Foundation (NSF) has a list of roof coatings that they have approved.

Roof coatings have a significant impact on the quality of the collected water. It’s essential to consider your area’s climate and local regulations when choosing a roof type.

Wrapping Up Optimal Roofing Choices

When it comes to rainwater collection, optimal roofing material choices depend on your climate and individual needs.

Be sure to take into account the age and condition of the roof, surface material compatibility, contamination risks, and maintenance requirements. Metal roofs are generally a safe choice for harvesting rainwater, but be aware that certain metal surfaces can leach contaminants into the water.

Elastomeric roof coatings can also be used to protect roofs and create a safe surface for collecting rainwater. Be sure to check the NSF list of approved products if you plan to use the collected water for drinking purposes.

With proper research and maintenance, your rainwater harvesting system should be able to provide you with clean, safe water for years to come.

If you’re considering a new roof for rainwater collection, Big Easy Roofing is here to help. Our team of experts can guide you through the process of choosing the optimal roofing material based on your specific needs and local climate conditions.

We provide a range of services, from installation to maintenance, ensuring your roof is always in top shape for efficient rainwater harvesting. Don’t compromise on the quality of your collected rainwater; contact Big Easy Roofing today and secure a sustainable water source for years to come.