Paths, patios and driveways

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 get a grease mark off suede without ruining the nap?

  Suede is the porous lower split of the hide with nap on both sides, dyed like aniline and uncoated. The trade guide states that cleaning agents will immediately darken nude leather — there is no cautious first application, because the first application is the result. Water is not a safe alternative either: the guide specifies deionised water because hard water containing minerals may cause rings. And the guide separately prohibits alcohol, strong solvents, high-pH cleaners and dish detergent on leather generally, as incompatible with modern finishes.

• How do I get a greasy mark off a leather sofa arm?

  The leather trade body prohibits both by name, and the reason is the finish rather than the hide. Modern leather finishes are WATER-BASED, and its banned list is built around what attacks them: any high pH cleaner, cleaners containing alcohol, strong solvents, and caustic household cleaners such as soap or dish detergent. The stated consequence is cracking or other damage to the surface. It is the same reason saddle soap and mink oil are on the list beside glass cleaner - traditional leather remedies formulated for finishes no longer used.

• There is a greasy mark on my aniline leather sofa. Can I use a leather cleaner on it?

  Aniline leather is not finished leather. The trade body describes it as porous and DYED rather than coated, and states plainly that cleaning agents will immediately darken nude leather. There is no surface film between the cleaner and the hide, so the liquid goes in rather than sitting on top, and the darkening is absorption into the leather rather than a residue that can be wiped back off. The prohibition list this catalogue carries for finished leather is about protecting a water-based FINISH; aniline has no finish to protect, which makes it more vulnerable rather than less.

The records

• Patio and driveway paving

  Thing to clean

  The most-asked outdoor cleaning question in this register, and the manufacturer's own guidance spends more words on how NOT to pressure wash it than on how to clean it.

• Driveway

  Thing to clean

  The largest hard surface most households own, and the one where the standard cleaning method removes the jointing along with the dirt.

• Concrete and stone paving

  Material or surface

  A hard outdoor surface whose weak point is not the slab but the JOINTS between slabs — which is why the standard advice to blast it with a pressure washer is fenced by an angle.

• Sandstone

  Material or surface

  A 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 surface

  The stone that survives what the others do not. A paving manufacturer names it among the materials acid washing leaves unaffected.

• Cement and mortar

  Material or surface

  Alkaline, porous and carbonate-bearing — which means acid dissolves it, and it damages an aluminium finish if allowed to dry on one.

• Moss and lichen

  Stain or problem

  Three different organisms treated as one green problem. Where they grow tells you more about the fix than any product does.

• Algae

  Stain or problem

  The green film outdoors, and NOT the same organism as the mould indoors. Where it grows is the diagnosis: shade, overhanging trees, or paving that does not drain.

• Oil and grease on textile

  Stain or problem

  The stain where the trade guidance switches from water to solvent — and the switch brings a warning the water route does not have.

• Pressure washing

  Method

  Permitted and fenced. A manufacturer's own guidance gives the angle, the setting and the check afterwards — and says excess shortens the life of the surface.

• Pressure washer

  Equipment

  Mechanical energy delivered by water alone. It removes what nothing else will and takes the surface with it more often than any other domestic tool.

• Jet-washing the patio every spring

  Claim or technique

  The manufacturer permits it and fences it — and the fence is about the angle of the lance, which is the part nobody follows.

• Cornflour or talc to draw out an oil mark

  Claim or technique

  The gentlest thing you can do to a porous surface, and two trade bodies name it as the first step rather than the last resort.