Cladding Maintenance: How to Keep It Looking New
To clean external PVC cladding, wash it with warm soapy water using a soft cloth, sponge, or soft-bristle brush, working from the top of each wall downward to prevent dirty water running over clean areas. Rinse thoroughly with clean water and allow to air dry. For most UK properties, cleaning once or twice a year — ideally in spring after winter weather and again in autumn — is sufficient to keep PVC-U cladding looking fresh and well-maintained. No painting, staining, sanding, or specialist treatment is ever required.
PVC-U cladding is often marketed as “maintenance-free,” and while it is true that it needs far less attention than timber, metal, or render, some basic care extends its lifespan, preserves its colour, and prevents the small issues that can develop into larger problems if ignored. This guide covers everything from routine washing to stubborn stain removal, seasonal inspection routines, and long-term care.
Why Maintenance Matters (Even for PVC-U)
PVC-U cladding does not rot, rust, or need repainting — but it is not self-cleaning. Over time, external surfaces accumulate:
- General dirt and dust — airborne particles from traffic, construction, and garden activities
- Algae and green growth — particularly on north-facing and shaded elevations where surfaces stay damp
- Bird droppings — acidic and can cause localised staining if left for extended periods
- Hard water marks — limescale deposits from sprinkler systems, hoses, or splashback
- Pollution and traffic film — darker deposits in urban and roadside locations
- Oxidation and chalking — on older or lower-quality PVC-U, the surface may develop a powdery residue
None of these will damage the structural integrity of the cladding, but they affect its appearance. A clad house that has not been washed for five years will look noticeably dirtier than one cleaned annually, even though the underlying material is identical.
The Annual Cleaning Routine
What You Need
| Item | Purpose |
|---|---|
| Bucket of warm water | Base cleaning solution |
| Washing-up liquid or mild detergent | Gentle cleaning agent |
| Soft cloth, sponge, or soft-bristle brush | Apply cleaning solution without scratching |
| Garden hose with spray nozzle | Rinsing (adjustable nozzle preferred) |
| Step ladder or telescopic wash brush | Reaching upper areas safely |
| Dedicated PVC-U cleaner (optional) | For stubborn marks and brightening |
| Safety glasses and gloves | Personal protection |
Step-by-Step Cleaning Process
1. Prepare the area Move outdoor furniture, plant pots, and other items away from the wall. Close any nearby windows to prevent water ingress.
2. Pre-rinse Hose down the cladding from top to bottom with clean water to remove loose dirt and debris. This prevents gritty particles from scratching the surface during washing.
3. Wash each section Dip your cloth, sponge, or brush into the warm soapy water and wash the cladding in manageable sections (approximately 1–2 m wide strips), working from top to bottom. Use gentle circular motions rather than aggressive scrubbing.
4. Pay attention to joints and rebates Dirt tends to accumulate in the horizontal joints between boards and in the rebates where boards overlap. Work the cloth or brush into these areas to dislodge trapped grime.
5. Rinse thoroughly Rinse each section with clean water before moving to the next. Do not allow soapy water to dry on the surface, as it can leave streaks and residue.
6. Allow to air dry PVC-U dries quickly in open air. Wiping dry is not necessary and risks introducing lint or fibres onto the surface.
7. Inspect while cleaning Use the cleaning session as an opportunity to inspect the cladding for any issues — loose fixings, cracked trims, gaps in sealant, or boards that have shifted.
Seasonal Maintenance Calendar
| Season | Tasks |
|---|---|
| Spring | Full wash to remove winter grime, algae, and moss. Inspect for frost damage to sealants and trims. Check that ventilation gaps at the base are clear of leaf debris. |
| Summer | Spot-clean bird droppings and insect residue promptly. Check that dark-coloured boards on south-facing walls are not showing signs of excessive thermal movement (buckling or gaps). |
| Autumn | Light wash if needed. Clear leaves and debris from the base of the cladding and from gutters. Check that downpipes are not overflowing onto cladding surfaces. |
| Winter | No cleaning required. After severe storms, visually inspect for wind-lifted boards, damaged trims, or impact damage from debris. |
Dealing with Specific Stains and Problems
Algae and Green Growth
Green algae is the most common issue on PVC-U cladding, particularly on:
- North-facing elevations that receive little direct sunlight
- Walls shaded by trees, fences, or neighbouring buildings
- Lower sections of cladding near ground level where splash-back keeps the surface damp
Treatment:
- Apply a dedicated algae remover (available from most builders’ merchants and DIY stores) or mix a mild bleach solution (1 part household bleach to 10 parts water)
- Apply to the affected area using a spray bottle or sponge
- Leave for 5–10 minutes (do not allow to dry)
- Scrub gently with a soft brush
- Rinse thoroughly with clean water
Prevention:
- Trim overhanging vegetation to improve sunlight and air circulation
- Ensure gutters and downpipes are functioning correctly — overflowing water promotes algae growth
- Consider applying a proprietary anti-algae treatment after cleaning
Bird Droppings
Bird droppings are acidic and can cause localised discolouration if left on PVC-U surfaces for extended periods.
Treatment:
- Soak the affected area with warm water to soften the deposit
- Wipe away with a soft cloth
- If staining remains, apply a PVC-U cleaner and wipe clean
Tip: Clean droppings promptly — fresh deposits remove easily; dried-on deposits are harder and may leave a ghost mark.
Rust Stains
Rust staining on PVC-U cladding is almost always caused by ferrous (non-stainless) fixings — nails, screws, or brackets that have corroded. The rust leaches from the fixing and stains the board below.
Treatment:
- Apply a proprietary rust remover suitable for PVC-U (check compatibility first)
- Wipe with a soft cloth
- Rinse thoroughly
Prevention: Always use stainless steel or hot-dip galvanised fixings when installing cladding. Replace any corroding fixings with stainless steel equivalents.
Silicone Sealant Residue
Excess sealant from installation can leave a visible residue on the cladding surface, which attracts dirt.
Treatment:
- Allow the silicone to fully cure (typically 24–48 hours)
- Carefully peel or slice off the excess with a plastic scraper (never use a metal blade, which will scratch the surface)
- Clean any remaining residue with a PVC-U solvent cleaner on a soft cloth
Scuff and Impact Marks
Wheelie bins, garden tools, and bicycles leaning against cladding can leave scuff marks.
Treatment:
- Try warm soapy water first
- For stubborn marks, use a non-abrasive cream cleaner (such as Cif Original) applied with a soft cloth
- For deep scuffs on coloured or woodgrain boards, the mark may be permanent if the co-extruded cap or foil has been damaged
Annual Inspection Checklist
Combine your annual clean with a systematic inspection:
| Component | What to Check | Action |
|---|---|---|
| Board fixings | Are any nails or screws loose, missing, or corroded? | Tighten, replace, or add fixings as needed. Use stainless steel replacements. |
| Board alignment | Have any boards shifted, buckled, or dropped? | Re-align and re-fix. Check expansion gaps — buckled boards often indicate missing expansion allowance. |
| Trims and corners | Are external/internal corner trims secure? Any gaps or pulling away? | Re-fix or replace damaged trims. Apply sealant at persistent gap locations. |
| Sealant | Is sealant around windows, doors, and penetrations intact? | Re-seal any cracked, shrunk, or missing sealant with a compatible external-grade silicone. |
| Ventilation | Are base vents and top vents clear and unobstructed? | Remove leaf debris, cobwebs, and insect nests. Ensure airflow path is unblocked. |
| Moisture signs | Any signs of moisture behind cladding (staining, efflorescence on masonry below)? | Investigate the source. Check for blocked cavities, failed flashings, or gutter overflows. |
| Impact damage | Any cracked, split, or broken boards? | Replace damaged boards. PVC-U boards can usually be individually replaced without disturbing adjacent boards. |
Pressure Washing: Proceed with Caution
Pressure washers are tempting for their speed and effectiveness, but they carry risks when used on PVC-U cladding:
The Risks
- Surface damage — high-pressure jets (above 100 bar) can strip foil-wrapped finishes, erode the co-extruded colour cap, and roughen the surface, making it more susceptible to future dirt adhesion
- Water ingress — pressure washers can force water behind boards through joints and fixings, saturating the cavity and potentially causing moisture damage to the wall behind
- Board displacement — the force of the jet can lift board edges, especially on aged installations where fixings may have loosened
If You Must Pressure Wash
- Use the lowest effective pressure setting — typically under 80 bar for PVC-U
- Keep the nozzle at least 300 mm from the surface
- Use a fan nozzle (25° or 40°) rather than a pinpoint jet
- Direct the spray downward, not upward into joints
- Avoid directing the spray at joints, fixings, and board edges
- Test on an inconspicuous area first
In most cases, a garden hose with a spray nozzle attachment and a soft brush will clean PVC-U cladding perfectly well. Pressure washing is rarely necessary and introduces unnecessary risk.
Long-Term Care: 10+ Years
After 10–15 years of service, PVC-U cladding may show some signs of ageing:
- Colour lightening — gradual and even, particularly on south-facing elevations. This is cosmetic and does not affect performance.
- Surface chalking — a powdery residue on the surface, more common on older or white boards. Regular washing removes the chalky layer.
- Slight embrittlement — PVC-U loses some flexibility over decades of UV exposure. Boards become slightly more prone to impact cracking but remain structurally sound for cladding purposes.
- Seal deterioration — silicone sealant around windows and penetrations has a typical lifespan of 10–15 years and may need renewal.
None of these issues requires replacement of the cladding system. Continued annual cleaning, prompt replacement of any damaged boards, and renewal of sealants and fixings as needed will keep the system performing and looking good well beyond its 25-year design life.
What Not to Use on PVC-U Cladding
| Product | Why to Avoid |
|---|---|
| Abrasive pads and scourers | Scratch the surface, removing the co-extruded cap and creating a rough texture that attracts more dirt |
| Wire brushes | Deep scratches and surface damage |
| Acetone / white spirit / thinners | Attack the PVC-U polymer, causing softening, discolouration, and surface crazing |
| Oven cleaner / caustic soda | Far too aggressive — causes permanent chemical damage |
| Bleach at full strength | Can discolour pigmented boards — always dilute (1:10 ratio minimum) |
| Dark-coloured cleaning cloths | Can transfer dye to the cladding surface, especially in warm conditions |
Frequently Asked Questions
How often should I clean my PVC-U cladding?
Once or twice a year is sufficient for most UK properties. Properties in areas with heavy pollution, near the coast (salt spray), or surrounded by trees (leaf debris and algae) may benefit from more frequent cleaning — three to four times per year.
Can I use a steam cleaner on PVC-U cladding?
Steam cleaners can be effective for stubborn algae and grime, but the heat can soften PVC-U if held in one spot for too long. Keep the nozzle moving and maintain a distance of at least 200 mm from the surface. Test on an inconspicuous area first.
Will white PVC-U cladding go yellow over time?
Modern white PVC-U formulations include UV stabilisers and titanium dioxide pigments that resist yellowing. Older or lower-grade products may show some yellowing after 15–20 years of UV exposure. Regular cleaning helps maintain the white appearance.
Can I replace a single damaged board without removing the surrounding boards?
In most shiplap and weatherboard systems, yes. Release the fixings on the damaged board, disengage it from the rebated joint, and slide it out. Slide the replacement board into position and re-fix. Some systems may require lifting the board above to disengage the joint, which is straightforward.
Is there a protective coating I can apply to PVC-U cladding?
Some proprietary PVC-U restoration products claim to protect and rejuvenate the surface. While these can temporarily improve the appearance of faded boards, they are not a substitute for proper cleaning and are not typically endorsed by cladding manufacturers. The best protection is regular washing and prompt attention to any damage.
