The bathroom is the hardest room in the house to light: little space, plenty of moisture, a low ceiling, and jobs as different as precise make-up in the morning and a relaxing bath at night. No wonder the flush-mounted bathroom ceiling light has been the most popular choice for years – it hugs the ceiling, stays out of the way of the shower, and its sealed construction copes with steam. In this guide we explain everything worth knowing before you buy: what IP44 really means and when you need IP65, where a ceiling light may sit relative to the shower and the bath, how many lumens a bathroom needs, which colour temperature won’t lie about your make-up, and how round fittings differ from square ones.