Worktops and stone
Five surfaces that look alike under a kitchen light and share almost none of their rules — including one whose maker warns against the cleaners sold for the others.
What this area turns on
The engineered quartz manufacturer prohibits oven and grill cleaners, dishwasher detergent, floor strippers, oil soaps and paint strippers on its surfaces, and then warns specifically against cleaners sold for granite, marble and other natural stones — a distinction most owners do not know exists. Meanwhile the stone trade divides stone by chemistry rather than by appearance: calcareous stone is calcium carbonate and is etched by any acid, siliceous stone is not, and a sealer is an impregnator that is repellent rather than stain-proof.
Where the obvious answer is wrong
Cases where the treatment that removes the problem is the treatment that ruins the surface it is on.
How do I remove limescale from a marble shower without ruining the marble?
Marble is also calcium carbonate. The acid cannot distinguish between carbonate deposited by hard water and carbonate that is the stone itself, so it dissolves both. The result on the stone is etching: a dull, slightly rough patch where the polished surface has been chemically removed. It is not a stain and there is nothing left on the surface to clean off.
Assessed and found wanting
Widely repeated techniques in this area that the evidence does not support, or supports only in part.
Sealing stone makes it stain-proof
Does not workThe stone trade's own guidance is unusually blunt about this: a sealer is a repellent, not a seal, and sealing does not make stone stain-proof.
The stone genuinely resists kitchen acids. The worktop is not only the stone, and the trade still does not recommend acidic cleaners on it.
Using a stone cleaner on a quartz worktop
Does not workIt looks like stone, it is sold as stone, and the manufacturer explicitly tells you not to use the products made for stone on it.
Oven cleaner for a stubborn worktop mark
Does not workReaching for the strongest thing in the cupboard when a mark will not shift. On engineered quartz the manufacturer prohibits it outright.
The records
Kitchen worktop
Thing to cleanThe surface most likely to be cleaned with the wrong product, because five materials that look similar have five incompatible rule sets.
Engineered quartz
Material or surfaceGround quartz bound in resin. Non-porous and acid-tolerant where marble is not — but the resin is the weak point, and the products sold for real stone are wrong for it.
Granite
Material or surfaceA silicate stone that resists kitchen acids where marble does not — and on which acidic cleaners are still not recommended, for reasons that are not about the stone.
Polished marble
Material or surfaceA calcium carbonate stone with a polished finish. Chemically attacked by acids, including household ones, and the damage is permanent.
Limestone
Material or surfaceCalcium carbonate like marble, but softer and more porous. Everything that damages marble damages it faster, and it absorbs more.
Travertine
Material or surfaceA calcium carbonate stone with open pores running through it, so it is acid-sensitive and absorbent at the same time — the worst pair of properties in a bathroom.
Sandstone
Material or surfaceA siliceous stone that mostly shrugs off acid — except where its own iron content reacts, and then acid washing turns the paving orange.
Slate
Material or surfaceThe stone that survives what the others do not. A paving manufacturer names it among the materials acid washing leaves unaffected.
Laminate worktop
Material or surfaceA printed decorative layer over a chipboard core. The surface is tough and the edge is not, and almost every failure starts at a joint.
Unglazed ceramic tile
Material or surfaceDefined by a number rather than a look: more than half a per cent water absorption. That figure is how a stain gets in, and it is why sealing matters here and not on porcelain.
Sealing
MethodBuying time rather than building a barrier. The stone trade corrects the name itself: these are impregnators, and they are repellent rather than stain-proof.
Etching versus staining
ScienceA stain sits on a surface and a mark from etching is a hole in it. They look similar, they need opposite responses, and cleaning harder makes one of them worse.
On a hard surface, contamination sits on top. In a porous one it goes in — and the regulator's own answer for porous material is sometimes to throw it away.