Granite composite sinks are tough and good-looking, and they don't need much looking after. A few simple habits keep them that way. This guide covers a daily, weekly and occasional routine, what never to use, and how to deal with the problems that do come up: limescale, stains, scuff marks and heat.
What a granite composite sink is
A "granite" or "quartz" composite sink isn't a solid block of stone. It's made from finely ground stone, such as granite or quartz, bound together with a resin. That gives a hard-wearing surface with a matt, stone-like finish. The finish is what you're looking after. Most problems come either from things building up on it, such as limescale and residue, or from things that wear it away, such as abrasives, harsh chemicals and heat.
A simple care routine
| How often | What to do | Time |
|---|---|---|
| Every day | Rinse, wipe and dry | About a minute |
| Every week | Wash the whole sink, plughole and drainer | About five minutes |
| When you notice a dull or chalky film | Remove limescale | About ten minutes |
Every day
After the last washing-up, rinse the sink with clean water to remove food and soap, then dry it with a microfibre cloth. If it's greasy, wipe it first with a soft cloth and a drop of washing-up liquid, then rinse. Drying matters most of all: water left to evaporate is what leaves limescale and water marks behind. Don't leave damp sponges, cloths or a washing-up bowl sitting in the sink overnight.
Every week
Give the whole sink a proper wash with warm, soapy water and a soft sponge or nylon brush. That includes the drainer grooves, the overflow, the plughole rim and around the base of the tap. Lift out the strainer or plug basket and clean it separately. Rinse everything thoroughly and dry. While you're doing it, look for the first signs of limescale: a dull or chalky film near the plughole or under the tap.
When you spot limescale or water marks
Use a limescale remover that's suitable for composite sinks. With Astraclean, put on gloves and eye protection, make sure the room is well ventilated, spray it undiluted over the affected areas (do not breathe spray), spread it with a soft cloth, sponge or brush, and leave it for 2–5 minutes. Then scrub lightly in circles, rinse thoroughly with warm water and dry. Keep it off the tap, because it isn't suitable for plated metals. For the full method, see How to remove limescale from a composite sink.
Dealing with common problems
Food and drink stains
Tea, coffee, red wine, beetroot, turmeric and tomato are the usual culprits. Rinse them away quickly rather than leaving them overnight. For a stain that's set, fill the bowl with warm water and washing-up liquid, leave it to soak, then scrub lightly with a nylon brush. Limescale gives stains something to cling to, so if a stain keeps coming back, remove the limescale first. Some manufacturers also suggest particular stain treatments for their sinks, so check your care guide before trying anything stronger.
Grey scuff marks from pans
Grey or black lines in the bottom of the bowl are often metal rubbed off pans and cutlery, sitting on the surface rather than in it. Manufacturers' advice varies here. Some suggest a paste of bicarbonate of soda and water with a soft sponge, so check what yours recommends. A sink grid or mat helps prevent new marks.
Whitening or patchy colour
If a dark sink is turning white or grey, it's usually limescale, but it can also be heat or chemical damage. See Why is my black composite sink turning white or grey? to work out which.
What never to use on a composite sink
- Wire wool, metal scourers, abrasive pads, scouring powders and abrasive creams
- Neat bleach or chlorine-based cleaners
- Oven cleaner, paint stripper, paint-brush cleaner, and solvents such as acetone or white spirit
- Drain unblockers poured over the sink surface. If you need one for a blocked drain, follow the instructions and rinse off any spill straight away.
- Any cleaner left on for longer than its label says, and never two cleaners mixed together
Heat, knocks and the tap
- Heat: let pans cool or put them on a trivet, not straight on the bowl or drainer. Don't pour hot fat or oil down the sink. It's bad for the waste and blocks drains.
- Knocks: composite is tough, but dropping a heavy cast-iron pan into the bowl can still chip it.
- The tap: most kitchen taps are chrome-plated. Clean them with a soft cloth and washing-up liquid, and keep sink and limescale cleaners off them unless the product says it's suitable.
Frequently asked questions
What's the best everyday cleaner for a granite composite sink?
Warm water, a little washing-up liquid and a soft cloth, followed by a rinse and a dry. Save stronger products for limescale and stains.
Can I use bleach on a granite composite sink?
It's safest not to. Many composite sink makers warn that bleach can discolour the surface, and some allow only a weak, diluted solution for a short time. Check your care guide, rinse thoroughly if you do use it, and never mix bleach with other cleaners.
Can scratches be removed from a composite sink?
Fine scratches are in the surface, so cleaning can't remove them, although cleaning out the dirt and limescale that collects in them makes them less noticeable. Ask your sink maker whether they recommend a care or restorer product, and use a sink grid to prevent new scratches.
Can I use Astraclean on quartz and granite sinks?
Yes. Astraclean is formulated for composite, granite and quartz sinks. Don't use it on unsealed natural stone or acid-sensitive surfaces such as marble, terrazzo, enamel or plated metals, and test a small hidden area first if you're unsure.