Planning a terrazzo floor
Terrazzo is a familiar floor in railway stations, airports and hospitals, and it suits a home just as well. People choose it for its speckled look and its long life. This page explains the choices you make when you plan one, so you can talk to a specialist with confidence.
What terrazzo is
Terrazzo is made of chips of marble or other stone set in a binder of cement or resin. The surface is then ground and polished smooth. A typical mix is about two parts chips to one part binder.
The name comes from the Italian word for terrace. The craft began in the Friuli region of north-east Italy, where people paved the ground by their homes with river stones. Printed references to it go back to 1581.
Choosing poured, tiled or precast
Terrazzo can be laid in place on site, which is called in-situ terrazzo. The specialist lays the screed and the terrazzo, and any shape can be formed. In-situ terrazzo can use a cement or a resin binder.
It also comes as tiles. Tiles made in the UK are square, in sizes from about 300mm to 600mm across, and can also be made rectangular. They are usually laid, grouted and then polished on site. Laying them straight onto a concrete base can save the need for a screed.
Precast pieces cover the rest. Stair treads, risers and skirting can be made to measure in the workshop, which saves time on site.
Picking the look you want
The chips decide most of the look. Marble, granite and quartz are common. Mother-of-pearl, and recycled glass, porcelain or mirror, are used too.
Tiles can be made to a colour you choose, or to your own mix of chips and binder. A sample is made for you to approve before the full order.
Planning for grip
A polished floor is lovely to look at, and grip matters where it may get wet. Slip resistance is measured with a pendulum test. A pendulum test value of 36 or more means a low slip potential. Ask for that figure for the finish you are considering.
Stair treads and in-situ work can include anti-slip inlays, which help on steps.
Caring for the finished floor
The stone chips are hard-wearing, but the binder is more porous, and cement most of all. A sealer helps the floor resist stains. It needs stripping and reapplying from time to time.
Wax is not recommended on terrazzo. It can make the floor dangerously slippery and dull its shine.
A newly laid cement floor takes days or weeks to cure. It may look patchy at first, and the colour evens out as it cures. Try any cleaning product on a small, hidden area first.
Finding a specialist
In the UK, the National Federation of Terrazzo Marble and Mosaic Specialists was formed in 1933. It gives technical advice on specifications for free, and keeps a list of members. Its technical inspection service is used by architects, contractors and clients when there is a dispute.