The most popular roofing materials for domestic buildings are clay, ceramic or concrete tiles, natural or man-made slate, asphalt shingles, aluminum, coated steel, timber, reeds and long straw. The latter two are used in thatched roofs.
Sustainable roofing materials should be able to insulate your home well and prevent heat loss; protect your home from the elements, particularly water while minimizing environmental impact at the same time.
Sustainability is determined by a number of environmental factors such as the amount of energy that goes into the production of the material, the availability of the resources to produce them, the pollution caused during manufacture and supply as well as the durability and recyclability of the roofing material.
Below are a few tips that will help you choose the right materials for you:
1. Carbon footprint
Consider the amount of energy required for production and the toxicity in emissions during production. Natural materials such as natural slate, timber and reeds have a lower carbon footprint than man-made materials. Their extraction requires low amounts of energy and does not cause any pollution apart from extraction and transport.
Check that the material can be recycled at the end of your roof's lifetime. Apart from asphalt shingles all other materials cited above can be recycled well although coated steel poses more of a problem because of its PVC coating.
3. Recycled content
Find out if the roofing material contains any recycled material. Obviously, the higher the percentage the better as this lessens the environmental impact. Also consider buying second hand roof tiles.
4. Metal coatings
Avoid materials with metal coatings like copper and zinc. Coatings can wash into nearby water sources over time and the metals are poisonous for aquatic life.
The longer a material lasts the better as you will not have to replace your roof so often. Clay, concrete, slate and aluminum can all last for 100 years. Asphalt will be struggling to reach 30 and timber and thatched roofs can last for about 50 years.
6. Renewable resources
Consider renewable resources. Timber is renewable and so are materials like reeds and long straw.
Your choice of roofing material will depend on many factors not least your budget, however, it is worth considering sustainability as one of them.