Polished concrete floors are low-maintenance, as they are more durable and easier to clean than many flooring options. Its relatively high coefficient of friction can make it non-slippery. Polished concrete reduces dust mite and allergen problems, and does not support mould growth. Anecdotal evidence suggests highly reflective polished concrete reduces lighting needs and improves natural lighting, but as yet there has not been a study to confirm this. Polished concrete flooring is hard wearing and will not chip or dent like softer surfaces such as timber. Mopping with warm soapy water once a week is the only maintenance required. A concrete floor that has been hardened and polished will have an extremely long life expectancy compared to other flooring. Polished concrete floor that has been properly maintained may give 100+ years of service.