The short answer
A properly prepped and sprayed UPVC frame using a UV-stable 2K coating like Kolorbond will last 15 to 25 years before the finish needs refreshing. Our written guarantee is five years. In practice, the work we've done in 2024 still looks identical to the day it was finished, and the same coating systems have a 20-year track record on commercial buildings.
What determines longevity
Three factors, in order of importance:
- Preparation. 70% of the work, 90% of the longevity. Frames that have been industrially degreased, sanded to break the surface glaze, and wiped with isopropyl alcohol will hold paint indefinitely. Frames that have been "given a quick wipe" will peel.
- Product choice. Kolorbond and other dedicated UPVC coatings are engineered for non-porous plastic substrates and UV exposure. Standard exterior paint or trade emulsion will fail inside two years no matter how good the prep.
- Application conditions. Above 8°C, under 80% humidity, no rain forecast for 24 hours. Cured to manufacturer spec. Sprayed wet-on-wet within the recoat window. Cure the same day, hardware refitted the next.
What kills a UPVC respray early
Five things, in order of how often we see them:
- Skipped degreasing. UPVC ships with mould-release compounds and quietly attracts a film of cooking smoke, road grime, and pollen. Paint over any of it and the bond fails.
- No sanding. UPVC is engineered to be smooth, which is the opposite of what paint wants. A 320-grit sand is non-negotiable.
- Acrylic exterior paint instead of a 2K system. Cheaper, faster, peels.
- Painting the gaskets. The rubber moves, the paint cracks. We mask gaskets and leave them.
- Painting in the wrong weather. Below 8°C or above 80% humidity means the lacquer cures wrong and the bond never reaches full strength.
What the five-year guarantee covers
The written warranty covers:
- Adhesion failure (paint lifting from the substrate)
- Peeling, cracking, or flaking
- Significant colour shift beyond normal weathering
It doesn't cover:
- Damage from impact, e.g. a kid with a bike against the front door
- Cleaning damage from harsh solvents
- Removal of overspray on adjacent surfaces (we mask, this doesn't happen, but it's noted)
- Pre-existing structural damage to the frames themselves
The warranty is in writing on completion and is fully transferable if you sell the property.
Maintenance over the years
Wash with warm soapy water and a soft sponge every six months. That's it. Don't use solvents, white spirit, or abrasive cleaners. Don't pressure-wash directly against the seals.
If you notice anything that looks like the finish lifting, send us a photo. Inside the warranty period, we come back and put it right at no cost. After the warranty, we'll give you an honest assessment, and most properly-sprayed jobs need nothing.
How our spec compares to other applicators
If you're getting multiple quotes, ask each applicator:
- What product are you using? (Should be Kolorbond, Tikkurila Aquaver, or equivalent.)
- How many coats? (Should be three, plus a primer.)
- How long is the guarantee? (Should be at least five years, in writing.)
- Is the guarantee transferable? (Should be yes.)
- What happens if it peels? (Should be: we come back and strip and respray at no cost.)
If any of those answers are vague, walk away. The cost of doing it twice is far higher than the cost of doing it right once.