Ceramic tile is one of the world’s oldest flooring materials. Tiles are a natural clay (earth) product baked at very high temperatures. Generally considered a sustainable material, ceramic tiles are inert and usually odorless. They are recyclable and available with recycled content.

Tiles are available in many varieties, glazed and unglazed, mosaic and quarry tile and in various sizes, surface textures and colors. Unglazed, often called Mexican pavers, are all clay usually requiring a coat of protective sealant before or after installation to prevent soiling and bacterial growth. They are usually less expensive than glazed.
The glass-like surface on glazed tiles is derived from sand. Some manufacturers offer glazed tiles containing recycled content of glass light bulbs, bottles, automobile windshields and waste from feldspar mining. Some glaze pigments are obtained from heavy metals and some conventional tiles can have radioactive glazes, particularly cobalt blue and some yellows. Radiation detectors are available to test the levels. Glazed tiles are water-resistant, require no sealant and permanently retain both their hard quality and their surface color.
Ceramic tiles are growing in popularity for many reasons, including offering good sustainable characertistics. They are highly durable, freeze-proof and easy to clean and maintain. They also have a high thermal storage capacity which means they retain their heat and emit it slowly — especially good in applications where climates are warm during the day and cool at night.
Although relatively abundant resources, clay and sand are nonrenewable. Sustainability issues include the mining of these raw materials which can produce soil erosion, pollutant runoff and habitat loss. Tile manufacturing is energy-intensive, but the industry is making many improvements in this area.
To ensure getting the most sustainable tile for your project, specify recycled content tile from a manufacturer using energy-efficient processing methods.
Installation involves adhesives and grout which are typically derived from petrochemicals and can contain plastic additives, considered inert when cured, but can emit VOCs while curing.
LEED points: MR Credit 4 for recycled content materials where appropriate.