The short answer is no, quartz worktops do not need sealing, and anyone trying to sell you an annual sealing service for quartz is worth questioning. That said, the reasons why matter, because they affect how you clean the surface and what can still damage it. Here is what we tell customers across London when they ask.
Quartz worktops are engineered stone, typically around 90 to 93 percent ground natural quartz bound together with polymer resins and pigments. The resin fills the microscopic pores that exist in natural stone, so the finished slab is non porous. There is simply nowhere for a sealant to soak in, and nothing for spills to soak into either.
Compare that with granite or marble, which are quarried natural stones with tiny capillaries running through them. Those genuinely benefit from an impregnating sealer every one to three years depending on use. It is one of the main reasons quartz has become so popular in busy family kitchens: red wine, coffee and turmeric sit on the surface rather than sinking in, provided you wipe them up within a reasonable time.
Non porous does not mean indestructible, and this is where some owners get caught out. The resin content is the weak point. Direct heat is the biggest risk: a pan straight off the hob can scorch or discolour the resin, and unlike natural stone the mark cannot be polished out easily. Always use a trivet, even for a kettle that gets moved around.
Strong chemicals are the other culprit. Bleach, oven cleaner, drain unblocker, paint stripper and anything with a pH far from neutral can dull or etch the resin binder over time. UV light is worth mentioning too: quartz is not recommended for outdoor kitchens or directly in front of large south facing glazing, as some colours can yellow or fade over several years.
Warm water, a drop of washing up liquid and a soft cloth cover almost everything. For dried on food, let a damp cloth sit on the spot for a few minutes rather than scraping with anything metal. A plastic scraper or the edge of an old bank card will shift stubborn residue without scratching.
For greasy film near the hob, a purpose made quartz cleaner or a diluted glass cleaner works well. In hard water areas, which covers most of London, limescale spotting around the tap and drainer is common. A cloth dampened with a 50:50 white vinegar solution, left on for no more than a minute or two and rinsed off thoroughly, will deal with it. Do not leave vinegar sitting on the surface for long periods.
A few situations blur the rule. Some fabricators apply a one off protective dressing at installation, which is a polish rather than a sealer, and it does not need renewing. If your worktop is actually quartzite, that is a different material altogether: it is a natural metamorphic stone, it is porous, and it does need sealing roughly every one to two years. The names get confused constantly, even by kitchen showrooms, so check your paperwork if you are unsure.
Very cheap engineered stone with a lower quartz content and more filler can be slightly more absorbent, and honed or matt finishes show marks more readily than polished ones, though they still should not be sealed. If a worktop sold to you as quartz is genuinely staining from water alone, speak to the fabricator, as that points to a product or manufacturing issue rather than something a sealant would fix.
Check your invoice or the brand name, as quartz is sold under names like Silestone, Caesarstone and Compac. As a rough test, quartzite feels colder and shows crystalline veining all the way through, while quartz patterns tend to be more uniform. A stonemason can identify it on sight if you are still unsure.
It will not harm the stone, but it cannot penetrate the surface, so it sits on top and may leave a hazy or streaky film. That residue can usually be removed with a suitable stone safe stripper or careful cleaning, and it does not need reapplying.
Usually yes. Most marks on quartz are surface residue rather than true stains, and a paste of bicarbonate of soda and water, or a specialist quartz cleaner, will lift them. Genuine discolouration from heat or harsh chemicals is resin damage rather than a stain and generally cannot be reversed.
Free survey and quote across London and 50 miles out. We will come and template once you are ready to commit.