The Durability and Sustainability Benefits of Clay Roof Tiles

Clay roof tiles have stood the test of time as one of the most trusted roofing materials, prized for their durability and eco-friendly characteristics. In an era where sustainability is paramount, the benefits of clay roofing tiles extend beyond their timeless appearance.

This article examines the inherent durability and sustainability of clay roofing tiles. From longevity to reducing energy consumption, tiling a roof with clay tiles offers a compelling solution for those looking to build eco-conscious structures.

What is a clay roof tile?

Clay tiles are made from natural clay that is moulded into various shapes and then fired in a kiln at high temperatures. Common shapes include flat shingles, barrel tiles and interlocking clay roof tiles.

The manufacturing process plays a crucial role in determining the quality and durability of clay tiles. High-quality tiles are made from dense, well-purified clay that is free from impurities and fired at optimal temperatures to achieve strength and weather resistance.

Clay tiles are installed in an overlapping pattern. Each tile slightly covers the one below it. Combined with the natural properties of clay, this overlapping design offers excellent protection against water infiltration and other environmental elements. Tiles are typically secured to the roof with a drill using nails, screws or wire ties.

5 types of clay roof tiles

Clay roof tiles are widely available in 5 distinct styles and profiles. In addition to shared properties including fire resistance, each offers unique characteristics suitable for different applications.

Are clay roof tiles sustainable?

When it comes to sustainable roofing solutions, clay tile roof materials are among the best options available. Clay tiles offer various environmental benefits over their lifespan. 

1. Longevity and durability

With proper installation, clay tiles last approximately 30-50 years or more without replacement. This is significantly longer than asphalt shingles which typically only last 15-30 years. The longevity of clay eliminates the recurring embodied energy and waste created by having to frequently reshingle. 

2. Natural and renewable materials

Clay tiles contain no synthetic or petroleum-based components. The clay and shale used to make the tiles are available from surface mines and quarries. Clay can often be sourced within fairly close proximity of where the tiles will be installed. This allows tiles to be produced from fully natural, renewable raw materials.

3. Low embodied energy

The firing of the clay tiles in kilns at temperatures between 980-1148°C (1800-2100°F) accounts for most of the energy required. However, this energy is balanced by the long lifespan. In contrast, concrete tiles need higher kiln temperatures of around 1204°C (2200°F). They also require more complex industrial processes, resulting in higher embodied energy.

4. Recyclable and reusable

At the end of their life, broken clay tiles can be crushed down and recycled into cement or as a base material for manufacturing new tiles without losing quality. Tiles that remain in good condition after removal are commonly reused on new roof installations.

5. Cool roof performance

The natural red and terracotta colour tones give them a solar reflectance of 30-50%. This compares to darker roofing materials like slate or asphalt. Both may only reflect 5-25% of solar radiation. By absorbing less heat from the sun, clay tiles can help reduce energy costs.

6. Improved indoor air quality

Roof clay tiles contain no volatile organic compounds (VOCs) that could potentially off-gas and reduce indoor air quality. Tiles also do not absorb or release other chemicals or contaminants. The fired clay material is hypoallergenic and will not create an environment for mould, bacteria or other allergens to grow. This promotes better indoor air quality.

7. Water permeability

While underlayment is required, the porous nature of clay allows any moisture penetration to slowly evaporate and release from underneath the tiles over time. This avoids trapping the moisture against underlayment and roof decking where it can cause deterioration. It helps increase the longevity of the full roof system.

How to maintain a clay-tiled roof

Clay tile roofs last a long time with proper installation and maintenance. However, neglecting maintenance will lead to issues like broken tiles, deteriorated underlayment and even structural damage. To keep your clay tile roof in top condition, follow these maintenance tips.

Annual inspection

Conduct a visual inspection of the full roof at least once per year. Be sure to look for the following.

• Cracked, broken or missing tiles.
• Deteriorated sealant around ridge caps, vents, skylights, etc.
• Debris accumulation in valleys or around protrusions.
• Damaged or deteriorated underlayment visible from underneath.
• Loose nails or fasteners.
• Fungus and mildew growth.

Cleaning

Clay tiles accumulate grime, moss and debris over time. This holds moisture and damages tiles or the underlayment. Occasional cleaning is recommended every 3-5 years.

• Use a roof brush or air blower to remove loose debris.
• Mix a solution of mild detergent and warm water.
• Scrub tiles gently with a soft-bristle brush and the detergent solution.
• Rinse thoroughly with clean water.
• Avoid harsh chemical cleaners which can damage tiles.

Repair or replace tiles

Broken or cracked tiles should be replaced promptly. Replacement will prevent water intrusion and damage. 

• Locate and remove any damaged tiles, setting them aside.
• Scrape away old sealant from the area.
• Apply a generous amount of roofing sealant to the area.
• Set and secure the new tile in place, pressing firmly into the sealant.
• Apply additional sealant around edges as needed.

Sealant maintenance

Roofing sealants used around spaces such as vents, chimneys and skylights will deteriorate over time. Check sealants annually and reseal as needed.

• Remove any cracked, dried, or failing sealant.
• Clean and prep the area per the sealant manufacturer's instructions.
• Apply a high-quality polyurethane or silicone-based roofing sealant.
• Tool the sealant for a smooth finish and proper adhesion.

Underlayment repair

If areas of the underlayment are damaged, they should be repaired quickly to maintain a waterproof barrier. However, the underlayment should not need full replacement more often than every 20-30 years on a well-maintained roof.

• Remove any damaged tiles to access the area.
• Cut away any deteriorated underlayment down to the sheathing.
• Install new self-adhesive underlayment and overlapping seams.
• Re-install tiles, setting them in a generous amount of sealant.

Clay tile roof vs concrete tile roof: What is the difference?

While both clay and concrete are popular materials, there are several key differences to be aware of. Below is a detailed comparison examining clay vs concrete roof tiles.