Veranda Paint Finishes

Of everything specified on a veranda, the frame colour is the choice people turn over the longest and the one that is hardest to revisit afterwards. Most of the structure is decided for you by circumstances — the wall dictates the brackets, the patio dictates the posts, the span dictates the depth of the beam. Colour is genuinely open. It is also the part you look at every day from the kitchen window, and because the coating goes onto the raw extrusion before anything is cut or assembled, it is fixed for the life of the structure.

At Roma Verandas the finish is specified alongside the frame rather than treated as a trim decision at the end. This guide explains what powder coating actually is and why it behaves nothing like paint on a timber fence, how RAL numbers and gloss levels translate into the way a frame reads in a British garden, and what caring for the finish involves in practice — including the short list of things that genuinely damage it.

What Powder Coating Actually Is

The aluminium arrives at the coating line as bare extrusion and is pretreated first: degreased, etched to remove the natural oxide layer and a little of the metal beneath, rinsed, then given a conversion coating that leaves a chemically keyed surface. Only then is the dry powder — usually a polyester formulated for exterior architectural use — sprayed on electrostatically, so charged particles are drawn evenly onto the earthed section, including the corners and returns that wet spray tends to miss. The section then passes through an oven at somewhere around 180 to 200 degrees, where the powder melts, flows out into a continuous film and cures.

What comes out is a film typically sixty to eighty microns thick, chemically bonded to the metal rather than sitting on top of it. No solvent evaporates and nothing skins over, so there is no brittle coat that eventually peels away in sheets the way paint on timber does. That is the whole reason an aluminium veranda has no repainting cycle. Where quality actually lives, though, is in the pretreatment, which you cannot assess by looking at a sample: rush it and the failure mode is filiform corrosion, a fine thread that creeps under the coating from a scratch or a cut edge, lifting the film as it goes.

RAL Numbers and the Colours People Choose

Colours are specified by RAL number, a European system of standardised shades identified by a four-digit code. It exists so a colour can be ordered, matched and reordered years later without anyone having to describe it, which removes the ambiguity of names like "charcoal" or "off-white". Several hundred shades exist, but British verandas cluster into a handful. RAL 7016 anthracite grey dominates, and there is no shame in it being the safe answer: it matches the windows, doors and rainwater goods now standard on UK homes, and it reads as near-black against a bright sky but as a soft grey in flat light, which stops it looking heavy.

The whites divide into RAL 9010, slightly warmer and softer, and RAL 9016, crisper and brighter. If you are matching existing white uPVC, note that uPVC white is not a RAL white and has usually aged a little, so a deliberate contrast often looks more intentional than a near-miss. RAL 9005 jet black is uncompromising and superb on the right house, but shows pollen, dust and water spotting more readily than anything else. One practical point on dark colours generally: an anthracite frame in full summer sun runs hotter and expands more than a white one, which is part of why glazing sits in gaskets rather than being clamped rigidly.

Gloss, Satin and Fine Texture

Gloss level is quoted alongside the RAL number and changes the character of a colour more than people expect. A high gloss finish reflects the sky and so shows every subtlety of the extrusion's shape — sharp on a crisp modern elevation, merciless along a three-metre beam — and it shows fingerprints and water spots most clearly. A true matt is forgiving of dust and looks very contemporary, but in dull weather it can read slightly chalky and it marks more easily when rubbed.

Most architectural aluminium therefore lands in the middle, on satin or fine texture. A fine-texture finish has a very slightly granular surface rather than a mirror-flat one, and it is the pragmatic choice for something living outdoors: the texture breaks up reflections and disguises both the light handling marks any frame picks up during installation and the fine scratching that posts beside a doorway inevitably accumulate. If you are undecided, look at a sample outdoors rather than under a showroom light, and look twice — once in sun, once on an overcast day, which is when the difference is most obvious.

Washing, and What Genuinely Damages a Finish

The routine is undramatic. Twice a year suits an ordinary inland garden: warm water, a mild pH-neutral detergent such as car shampoo or washing-up liquid, a soft cloth or sponge, then a rinse with clean water so nothing is left to dry on. Work in the shade, because detergent drying in direct sun leaves streaks more annoying than the dirt was. Frequency should rise where the environment is aggressive — within a few hundred metres of the coast, where airborne salt settles constantly, or beside a busy road, where brake dust and diesel soot form a fine acidic film. The parts needing attention are the ones rain never reaches: the underside of the beam, the sheltered face of a post.

What to avoid is a short list, but it matters. No solvents, since cellulose thinners, acetone and white spirit all attack a polyester film. No abrasive pads or scouring creams, which burnish a matt finish into a shiny patch that cannot be undone. No strongly alkaline or acidic cleaners, which includes several common patio products and brick acid. And no pressure washer close to the frame — the coating usually survives, but water is driven past gaskets into joints where you do not want it. The most common cause of permanent marking, though, is cement, mortar or render splash left on during other building work. Wet mortar is strongly alkaline and etches a coating if allowed to dry and sit; it needs washing off the same day, not the following weekend.

Scratches, Touch-Up and Guarantee Conditions

Deep damage is rare in normal use, and most of what looks like a mark is a surface deposit that washes off. Where there is a genuine scratch, matching touch-up paint is available in the relevant RAL from system suppliers. Be realistic about what it achieves: an air-dried lacquer is a different material from an oven-cured powder, so it sits slightly differently in gloss and weathers at a different rate. A touch-up on an edge, an underside or a post base disappears; one in the middle of a well-lit beam face tends to stay visible as a change in sheen. If a scratch has gone through to bare metal, sealing it promptly matters more than the cosmetics.

Finish guarantees are worth reading rather than assuming. Coating guarantees are generally conditional on reasonable cleaning, and typically exclude mechanical damage, cleaning with abrasives or solvents, damage from building materials, and prolonged contact with incompatible substances — fresh cement, some sealants, run-off from treated timber, direct contact with dissimilar metals. Coastal locations are usually treated separately, with a shorter interval between required washes. Nobody is going to audit your cleaning diary, but if a seafront frame that has never been washed blooms after a few years, that is the conversation you will end up having, and a bucket twice a year avoids it.

Choosing Something You Will Still Like

The best advice on colour is unglamorous. Judge it from a physical sample held against your actual brickwork, outdoors, at two different times of day — not from a screen and not from a rendered visual, both of which flatten the differences that matter. Remember too that the frame does not sit against the wall but stands away from it, so for much of the day you see it against the sky rather than the house. That is why anthracite works equally well on brick, render and stone, and why an exact match to existing joinery matters less than most people assume.

If matching an existing colour does matter to you, say so early: it is straightforward to allow for at specification stage and impossible once sections are coated. We would far rather spend part of a survey appointment talking about how a colour will look in your particular light than have someone choose in a hurry and live with a nagging doubt. It is one of the few decisions on a veranda that is entirely yours, and it deserves to be made properly.