Sustainable Solutions: Cement Roof Tiles for Eco-Friendly Roofing Systems

The search for sustainable building materials has intensified as we strive to reduce our environmental impact. One innovative solution is the use of cement roof tiles for eco-friendly roofing systems. For this feature, we discover how cement roof tiles are paving the way for a more sustainable future in construction.

What is a cement roof tile?

The primary components of cement roof tiles are Portland cement, sand, water and mineral pigments for colouring. Some tiles also incorporate reinforcing fibre materials, such as polypropylene or fibreglass, to enhance their strength.

The composition makes them an eco-friendly choice. This is because they can incorporate recycled materials such as fly ash or slag. There are several different types of cement roof tiles.

• Flat tiles: Also known as slate or shingle tiles, cement flat roof tiles are one of the most common types. They are rectangular and offer a sleek, modern look. Flat tiles are suitable for various roofing styles and are often used in residential and commercial settings.
• Barrel tiles: Barrel tiles have a semi-cylindrical shape that creates a distinct, curved profile. These tiles are commonly associated with Mediterranean or Spanish-style architecture. They are well-suited for warm climates because of their excellent heat reflection properties.
• Interlocking tiles: As the name suggests, cement interlocking roof tiles are designed to overlap and interlock with each other. They create a seamless and watertight roof with tiles. These tiles are often used in areas with high wind or tough weather conditions, as they offer superior resistance to uplift and water infiltration.
• High-profile tiles: High-profile tiles feature a raised central portion that creates a distinct, dimensional appearance. These tiles are often used in traditional or historic building styles and add a distinctive look to a roof.
• Shake tiles: Shake tiles are designed to mimic the rough, rustic appearance of traditional wood shakes. They are often used in residential settings for a warm, natural aesthetic to a building's exterior.

6 sustainable benefits of cement roof tiles

Cement roof tiles offer various benefits that make them a sustainable choice for roofing systems. Fitting cement roof tiles can contribute to achieving credits under the Building Research Establishment Environmental Assessment Method (BREEAM). Here are 6 key eco-friendly benefits of fitting cement tiles.

1. Reduced carbon footprint

The manufacturing process of cement roof tiles is relatively less energy-intensive than other roofing materials, resulting in a lower carbon footprint. Concrete tile production emits approximately 0.2 metric tons of CO2 per tonne of product. This is significantly lower than the emissions associated with asphalt shingles (0.5 metric tons of CO2 per tonne) or clay roof tiles (0.4 metric tons of CO2 per tonne).

2. Durability and long lifespan

With proper installation and maintenance, they can last for 50 years or more. This greatly reduces the need for frequent replacements and waste generation. Conducting the right maintenance techniques, cement tiles can have a lifespan of up to 100 years, depending on climate and exposure conditions.

3. Low maintenance requirements

Cement tiles are relatively low-maintenance, requiring minimal upkeep and repairs throughout their lifespan. Generally, cement tile roofs require re-roofing or significant repair work every 50-70 years. This is compared to asphalt shingles which may need replacement every 15-20 years.

4. Energy efficiency

Cement tiles can contribute to the overall energy efficiency of a building. Light-coloured cement tile roofs can reflect up to 65% of solar radiation. It reduces energy consumption by up to 22% compared to dark-coloured asphalt shingles.

5. Water management

Properly installed cement tiles effectively manage rainwater runoff, reducing the risk of erosion and minimising the strain on stormwater management systems. Cement tile roofs can reduce stormwater runoff by up to 20% compared to other roofing materials. This is because of their ability to absorb and slowly release water.

6. Fire resistance

Cement roof tiles are naturally fire-resistant. They provide an added layer of safety and reduce the risk of fire-related damage. Cement tiles have a Class A fire rating, which is the highest level of fire resistance for roofing materials.

Can you recycle cement roof tiles?

Yes, cement roof tiles are highly recyclable. Their primary components are easily separated and reused in various applications. This makes cement tiles an environmentally friendly choice. They can be diverted from landfills and given a new life after their initial use on roofs. Below are some examples.

• Concrete aggregate: The crushed tile material can be used as an aggregate in new concrete mixes. This minimises the need for newer aggregate and offers a sustainable alternative. Recycled aggregate can be used in various concrete applications, such as foundations, floors or walls.
• Road and construction base: Recycled tile rubble can serve as a base material for road construction and provide a stable foundation for paving. It can also be used as a base for other construction projects, such as building foundations or retaining walls.
• Landscape and hardscape elements: Larger pieces of recycled tiles can be repurposed as decorative landscaping elements, such as pathways, borders or mulch alternatives. They can also be used in hardscape applications, such as paving stones or retaining wall blocks.
• Soil amendment: Finely crushed tile material can be used as a soil amendment, improving drainage in garden beds or lawns.

Do cement tiles offer better sustainability than concrete?

When it comes to cement vs concrete roof tiles, there are notable differences in their composition and manufacturing processes. These differences impact their sustainability and eco-friendliness. Below, we explore them in detail.

How to lay cement roof tiles

Proper installation is crucial for ensuring the longevity and sustainable performance of cement roof tiles. Here are the steps on how to lay roof tiles, including techniques and considerations to keep in mind throughout the process.

Step 1 - Gather tools and materials

Below are the tools and materials you will need to successfully carry out each step.

Step 2 - Preparation and setup

Ensure the roof deck is properly prepared, with adequate underlayment and moisture barriers in place. Calculate the number of tiles needed, factoring in waste and overlap requirements. To do this, you first need to measure the size of your roof using this calculation: Roof width (m) x roof slope height (m) = half roof area (m²). The following calculation determines how many cement roof tiles you will need: Roof width (m) x roof slope height (m) = half roof area (m²). 

Step 3 - Setting the first row

Start at the eaves or the bottom edge of the roof. Lay the first row of tiles with the appropriate overhang, typically 1-3 inches. Use a chalk line to ensure a straight line. Secure each tile in the first row with the recommended number of nails or screws, ensuring they penetrate the roof deck properly.

Step 4 - Overlapping and staggering

For the following rows, overlap the tiles by approximately 75mm - 100mm (3-4 inches). Stagger the joints between tiles in adjacent rows by at least 150mm (6 inches) for a more secure and aesthetically pleasing installation.

Step 5 - Cutting tiles

Use a tile cutter or wet saw to cut tiles as needed for proper fit around vents, valleys or other obstacles. Mark the cut line with a chalk line or straightedge and make clean, straight cuts to ensure a tight fit.

Step 6 - Securing tiles

Secure each tile with the nails or screws, ensuring they penetrate the roof deck properly. Be sure to use roofing nails or screws specifically designed for securing roof tiles, with appropriate length and corrosion resistance. Drive nails or screws in a straight line, avoiding angled or skewed installations that could compromise the tile's integrity.

Step 7 - Ridge and hip tiles

Install hip and roof ridge tiles on roof peaks, using appropriate ridge closure pieces or sealants for a watertight finish. Ensure proper overlapping and secure installation of ridge and hip tiles to prevent water infiltration and wind uplift.

How to maintain a sustainable cement-tiled roof

Proper care is essential to ensure longevity and optimal performance. Here are the key eco-friendly and sustainable practices for maintaining your cement tile roof.

Regular inspections and cleaning

• At least once a year, conduct visual inspections of your roof to check for any damaged, cracked or missing tiles.
• Remove any debris, such as leaves, branches or dirt, from the roof surface and valleys. This prevents moisture buildup and potential damage.
• Use a soft-bristle brush and eco-friendly cleaning solutions, such as a mixture of water and vinegar or mild detergent, to gently clean the tiles without harsh chemicals.

Moss and algae removal

• Moss and algae can grow on cement tiles in shaded or damp areas, potentially causing damage if left unchecked.
• Use environmentally friendly solutions, such as a mixture of water and baking soda or a specialised eco-friendly roof cleaner, to remove moss and algae.
• Avoid using harsh chemical cleaners or pressure washers. They can damage the tiles and contribute to environmental pollution.

Repairing damaged tiles

• Replace any cracked, chipped or broken tiles quickly to prevent further damage and water infiltration.
• Use cement-based patching compounds or special tile adhesives to fill crack areas or secure loose tiles. This ensures a tight and durable repair.
• Consider using recycled or salvaged replacement roof tiles. It reduces the environmental impact of new tile production.

Maintaining proper ventilation

• Ensure adequate roof ventilation by keeping vents and ridge caps clear of debris and obstructions.
• Proper ventilation prevents moisture buildup, which can lead to mould, mildew and premature tile deterioration.

Sealants and coatings

• Use eco-friendly sealants, stain solutions or coatings specifically designed for cement tiles. This protects them from environmental factors and extends their lifespan.
• Look for low-volatile organic compound (VOC) or water-based products that have minimal environmental impact.
• Avoid sealants or coatings containing harsh chemicals or solvents. They can be harmful to the environment.