Porcelain paving is vitrified ceramic — fine clays fired above 1,200 °C until the body fuses into a near-glass density with water absorption below 0.5%. That single property drives every practical difference from concrete and natural stone slabs.

Because almost no water enters the slab, frost cannot flake it, moss and algae find no purchase, and spilt wine, oil, and barbecue grease sit on the surface instead of soaking in — cleaning is a wash-down rather than a chemical treatment. Colour and pattern are fired through or printed under a dense wear layer, so a porcelain patio keeps its day-one appearance where concrete fades and stone weathers.

The structural format for ground use is the 20 mm slab, engineered for external loads; 10 mm interior porcelain is not a paving substitute. The trade-offs are workability and cost: porcelain demands diamond-blade cutting, specific primers or pedestal systems for laying, and a higher price per square metre than concrete — repaid over the years you spend not sealing, scrubbing, or replacing it.

Not when the correct grade is specified — outdoor porcelain is manufactured with textured, matt surfaces specifically rated for wet exterior use, and slip resistance is one of its published numbers rather than a guess.

Look for the slip rating on the datasheet: the common European scale is the R rating (R9 to R13), and external paving should be R11 or better, with barefoot wet areas like pool surrounds also carrying an A/B/C barefoot classification (aim for B or C). Equivalent pendulum test values (PTV 36+) appear in UK and other specifications. These ratings come from standardised tests, so two R11 slabs from different factories deliver comparable grip.

The practical cautions: interior-finish porcelain (polished or lappato) is genuinely slick outdoors and does not belong there — the classic error is extending indoor tiles onto a terrace for visual flow without switching to the matching 20 mm R11 external version, which most ranges now offer precisely for that continuity. Keep the texture working by keeping it clean; a film of algae on any surface defeats its rating. And at steps and pool edges, add the belt-and-braces details — nosing profiles and drainage falls — that no tile rating replaces.

Not the way concrete slabs forgive. Porcelain's near-zero absorption means a traditional wet mortar bed cannot suck into the slab and grip it — un-primed porcelain on plain mortar debonds, which is the single most common porcelain-patio failure.

The three accepted methods:

1. Full mortar bed + slurry primer — the standard garden build-up: compacted sub-base, a full (never spot-dabbed) semi-dry mortar bed, and a cementitious priming slurry brushed onto the slab back immediately before laying. The primer is not optional; it is the bond.
2. Pedestal systems — adjustable supports under each corner for roof terraces, balconies, and anywhere drainage, falls, or access to waterproofing matters. The 20 mm slab's stiffness is what makes this possible; joints stay open and water passes through.
3. Bound gravel/porcelain-specific adhesive systems on concrete bases for driveways and heavy duty, per the system maker's specification.

Complete the job like tiling, not like flag-laying: joints of at least 3–5 mm filled with a brush-in or flowable jointing compound rated for porcelain (dry sand washes out and stains), falls of about 1:80 away from buildings, and cuts made with a continuous-rim diamond blade, wet where possible. Laid this way, the patio is effectively maintenance-set for decades.

No — and this is one of its defining advantages. The vitrified body and dense wear layer are effectively non-porous as manufactured, so there is nothing for a sealer to fill: water, oil, and dirt stay on the surface, and slabs never develop the soaked-in staining that drives the sealing cycle on natural stone and concrete.

Routine care is correspondingly simple: sweep, and wash with warm water and a mild alkaline or pH-neutral cleaner as needed; a pressure washer on a moderate setting is safe (on wide fan, kept moving) for seasonal clean-downs. Stubborn marks — cement haze from installation, rust spots from furniture, barbecue fat — lift with the appropriate specialist cleaner rather than aggressive acid, which the tile tolerates but grout joints and adjacent materials may not.

Two honest footnotes. First, the joints are the maintenance item: brush-in compounds and grouts can discolour or grow surface moss in shaded corners, and an occasional joint refresh keeps the whole patio reading crisp. Second, some very textured finishes hold fine dirt in their grip pattern and reward an annual stiff-brush wash. Neither involves sealing the tile itself — money saved on sealants over a patio's life typically covers the porcelain price premium on its own.

Thickness is the defining spec: 20 mm is the outdoor structural standard, rated for pedestrian terraces on mortar, gravel, or pedestals. A growing 30 mm tier serves driveways and heavier loads (always on a bound base per manufacturer guidance), while 10 mm exterior-finish tiles are for bonded-to-concrete installations only — never loose-laid.

Formats run large by paving standards: 600×600 mm and 900×600 mm are the workhorses; 800×800 and 1,200×600 make contemporary statements; plank formats (1,200×300, 1,200×400) carry the wood-look ranges; and 2 cm 'slab' ranges reach 1,200×1,200 for pedestal decks. Coordinated pieces — bullnose step treads, copings, pool-edge grates — come from the better ranges, which matters at design time because matching trims from another source rarely matches fired colour.

Selection guidance by project: pedestal and roof work favours squares up to 600–900 mm for wind and handling; gardens laid on mortar handle any format, with larger slabs demanding flatter bases and two-person lifting (a 1,200×600×20 slab is ~35 kg); wood-look planks want a 1/3 stagger, not 50%, to keep any slight bowing invisible. Order 10% extra for cuts and future repairs from the same batch — porcelain shades vary subtly between production runs, and the spare box in the garage is the only guaranteed colour match.

Porcelain's printed-then-fired surfaces now cover essentially every paving aesthetic:

• Stone looks — limestone, sandstone, slate, travertine, and granite effects dominate the market, delivering the fossil detail and tonal drift of quarried stone with none of its sealing and staining life. The better ranges print dozens of unique faces per design, so repeats are hard to spot on a full patio.
• Concrete and cement looks — the minimalist grey palette from warm putty to anthracite, uniform enough for crisp modern schemes yet without concrete's blotchy weathering.
• Wood looks — plank-format slabs with grain texture underfoot as well as in print. The convincing ones pair high-variation printing with a structured surface; viewed at standing height on a laid deck, current-generation wood-effect porcelain passes for timber decking until touched — and unlike decking it never rots, greys, or feeds a single splinter. It has become the default for pool surrounds wanting timber warmth with barefoot-safe grip.
• Terrazzo, ceppo, and decorative looks for statement terraces.

Two judgement aids: always assess from at least three full slabs (single samples exaggerate repeat concerns) and view them wet as well as dry, since outdoor life is both. And match the look to the joint treatment — stone looks carry wider sanded-tone joints naturally, while concrete looks reward tight joints in a matching grey — because on a finished patio the joints are as visible as the print.

Pools — yes, it has become the premium standard. The chemistry survives chlorine and salt systems without etching; near-zero absorption means no waterline staining or frost damage in emptied winter pools; and barefoot-rated textured finishes (class B/C, R11+) give wet-foot grip that polished stone cannot. Coordinated bullnose copings and grating pieces finish the edge. Two specification notes: choose a colour tone tested for barefoot summer heat (deep anthracite gets hot in full sun in hot climates) and set falls so splash water drains away from the pool surround rather than ponding on the texture.

Driveways — yes, with the structural build-up. The slab itself is strong in compression but a paving unit is only as strong as its bed: vehicular porcelain means the 30 mm (or specified 20 mm system) product laid on a reinforced concrete base with porcelain adhesive or a bound bed, per the manufacturer's vehicular specification — never loose-laid on sand/gravel like block paving. Joints go in with high-strength jointing mortar. Done to spec, the result is a driveway immune to oil-drip staining (the family car's gift to concrete) and tyre-scuff marking, at a build cost above block paving but with a permanently-clean face block paving cannot hold.

The shared caveat: both duties depend on edge details — copings and step noses at pools, edge restraints at drives — from the same engineered range, not improvised in another material.