Composite & PVC Cladding: Installation, Clips, Prices

Timber cladding may be the reference for contemporary homes, but it demands regular maintenance and visibly ages. For anyone seeking a zero-maintenance facade for 30 years, composite or PVC cladding is the modern alternative: boards in wood-plastic composite, fibre cement, expanded cellular PVC or aluminium composite, fixed to an aluminium subframe with hidden clips. The result is clean, the colour stable, and a garden hose once a year is all the upkeep needed. But everything hinges on two technical points: managing thermal expansion (enormous on composite and PVC) and ventilating the rainscreen cavity. Poorly installed composite cladding buckles, bangs or detaches within two summers. This guide covers the families, the aluminium subframe, fixing clips, expansion gaps and prices per m2.

What is composite or PVC cladding?

The term “composite” is a commercial catch-all grouping four technically very different families. Before choosing, you need to understand what is in the board.

The 4 families of non-timber cladding

• WPC (Wood-Plastic Composite) — A mix of 50 to 70% wood fibre and 30 to 50% polymer (PVC or polyethylene). Timber-like appearance but rot-proof. Common brands: Silvadec, Fiberon, Cedral WPC, UPM ProFi. This is the modern “fake wood”.
• Fibre cement — Portland cement (85%) reinforced with cellulose fibre and sand. Mineral or timber-imitation appearance, non-combustible A2-s1,d0, stable over time. Brands: James Hardie, Eternit, Cedral Click, Swisspearl. This is the durable, fire-safe choice.
• Cellular expanded PVC — Rigid PVC with a cellular core, very lightweight and affordable. Smooth or false-clin board profile. Brands: Freefoam, Vinyplus, Kerrafront, VOX. This is the entry-level renovation option.
• Aluminium composite panels (ACM, Alucobond panels) — Two 0.5 mm aluminium sheets sandwiching a mineral A2 core. Used in commercial buildings, public buildings and architect-designed houses. Beyond self-build budget and skill level, included for general knowledge.

Why choose composite cladding over timber

The unbeatable argument: zero maintenance whatsoever. No oil stain, no wood stain, no uncontrolled greying, no wood-boring insects, no algae on the north elevation. One rinse with a garden hose once a year is enough.

Key benefits

• Zero maintenance for 25 to 50 years depending on the family
• Stable colour guaranteed 10 to 30 years by the manufacturer (except cellular PVC)
• Rot-proof — no decay, no fungal attack, no insect damage
• Favourable fire class — fibre cement is A2 (non-combustible), useful in urban areas or close to boundaries
• Dry installation — no drying time, work in any weather except frost and strong wind
• Impact resistance — fibre cement leads, composite and PVC are more vulnerable
• EWI compatibility — ideal for renovation with external wall insulation

Limitations to know

• High thermal expansion — up to 3 mm per metre for WPC and PVC between winter and summer
• Industrial look — even the best composites do not fool the eye at 2 m from the wall
• Mixed environmental record — plastic content, difficult end-of-life (except fibre cement)
• Sometimes high cost — premium fibre cement and ACM exceed quality Douglas fir
• Specific technical requirements — aluminium subframe, clips, expansion gaps: not the same logic as timber
• Noise under hail — ACM and PVC “drum”, less noticeable on WPC and fibre cement

Anatomy of a ventilated composite cladding system

Like timber cladding, composite cladding is always installed as a ventilated rainscreen, never fixed directly to the wall. The layer order from inside to outside:

1. Loadbearing wall (concrete block, aircrete block, timber frame)
2. EWI insulation (mineral wool, EPS, wood-fibre board) fixed to the wall
3. Breathable membrane (HPV) over the insulation — stretched, stapled, taped
4. Adjustable aluminium fixing brackets (taking up wall-flatness defects)
5. Vertical aluminium rails (T-section or omega-section profiles)
6. Ventilated rainscreen cavity (40 to 80 mm) created by the subframe
7. Stainless steel fixing clips on the aluminium rails
8. Cladding boards interlocked onto the clips, never screwed face-on

The key difference from timber cladding: the subframe is aluminium, not timber. Aluminium is mandatory for two reasons — it withstands permanent moisture without rotting, and its thermal expansion coefficient is close to that of composite boards, so it moves with them. A timber batten cannot do this.

The critical point: thermal expansion

This is the trap that ruins badly planned projects. A 3 m composite board on a south-facing elevation goes from -10°C in winter to +60°C in summer sun (surface temperature, not air temperature). That 70°C delta causes:

What this means on site

• End gaps — 3 to 5 mm at the corner trim and end profile, depending on material and board length
• “Floating” clips — clips must grip firmly enough to hold, but allow longitudinal sliding of the board
• One fixed point per board only — at the centre, a through-screw into the subframe; all other clips allow sliding
• Open vertical joints of 3 to 5 mm between boards end-to-end, with a ventilated joint flashing
• Shorter boards rather than longer — boards over 3.60 m are rarely used on composite cladding, even if the manufacturer offers them

The aluminium subframe: brackets and rails

Fixing brackets

They are used to correct wall flatness (tolerance: 10 mm over a 2 m straightedge). On a new, flat wall, one bracket every 80 cm to 1 m vertically. On an older, deformed wall, reduce to 60 cm.

• Material: 6060 aluminium or stainless steel — never galvanised steel (rusts in contact with damp EWI)
• Thermal break: plastic washer or thermal-break bracket is mandatory in an insulated wall (otherwise a linear thermal bridge)
• Fixing: hammer-in anchors in concrete block, or expansion anchors in poured concrete. Pass cleanly through the insulation without crushing it.

Vertical rails

• Aluminium profiles: T-section (50×50) or omega-section — stiffer than timber battens
• Standard spacing: 600 mm for 190-200 mm wide boards, reduce to 400 mm in highly exposed areas or for thin boards
• Cutting: mitre saw with a metal blade, file the cut edges
• Fixing to brackets: A2 stainless self-drilling screws, moderate torque to allow adjustment

Fixing clips

This is the main difference from timber cladding: on composite, no screws are visible on the face. Boards are held by stainless steel clips that hook into the upper groove of the board and screw onto the aluminium rail.

Three types of clip

• Manufacturer-matched clips (supplied by the cladding brand) — designed for a specific rail spacing, perfectly dimensioned
• Universal clips — more flexible, compatible with several ranges, but check manufacturer compatibility
• Concealed direct screws — some systems (for example Cedral Click fibre cement) use a screw in the upper tongue, covered by the next board

Installation steps, in order

Step 1 — Prepare the substrate

Wall clean, dry and free of algae. If EWI: insulation boards glued and plugged, breathable membrane stretched and taped. Tolerance: 10 mm flatness over a 2 m rule. If worse, correct with packers or re-think the subframe.

Step 2 — Install the breathable membrane

Roll out horizontally from bottom to top, 100 mm overlap downward (in the direction of water flow), staple to rigid insulation or double-sided tape on EPS. Joints sealed with HPV adhesive tape. No random punctures.

Step 3 — Mark out and fit brackets

Snap chalk lines and use a laser level to mark vertical lines at the chosen spacing (600 mm standard). Drill and plug brackets through the membrane — sealing tape around the anchor sleeve is recommended on exposed elevations.

Step 4 — Aluminium rails

Fix vertical rails to the brackets, at least two brackets per rail. Check plumb with a plumb bob or laser. Rails must be perfectly co-planar — the whole geometry of the cladding depends on them.

Step 5 — Starter profile

The starter profile (aluminium drip flashing) is fixed perfectly level at the base of the wall, at least 200 mm above finished ground level. It incorporates a ventilated vermin mesh (5 mm mesh) at the cavity air inlet.

Step 6 — First board and clips

The first board sits in the starter profile, then clips are screwed to the rails gripping the upper groove of the board. Never over-tighten: the clip must allow the board to slide for thermal movement.

Step 7 — Building up the boards

Board by board, tongue-and-groove interlocking. Each board is placed, levelled, then clipped. Check alignment every 4-5 boards (a 1 mm error accumulates quickly).

Step 8 — Vertical joints

Between two boards end-to-end, leave a 3 to 5 mm gap and fit a ventilated joint flashing (supplied by the manufacturer). This flashing incorporates an air filter and drains water into the cavity.

Step 9 — Corner and end trims

Projecting corners: lacquered aluminium angle trim matching the cladding colour, fixed first, boards butting against it with a 3-5 mm gap. Returning corners: U-profile providing the required gap on both sides.

Step 10 — Top finish

Coping flashing at the top of the cladding to close off the ventilated cavity outlet neatly (under the roof overhang). 5 mm insect mesh integrated.

Critical details: where problems occur

Window reveals

• Aluminium sill flashing with drip edge and upstand under the breathable membrane
• Aluminium return profile at the back of the reveal, cladding butting up with expansion gap
• MS polymer sealant between the frame and the return profile — never between cladding and frame

Floor-level junctions

Z-flashing in aluminium with continuous cavity. Ventilation must pass through this level. Check that the insect mesh does not restrict airflow.

Projecting corners

Pre-formed 90° aluminium angle trim (the cleanest option), or two individual corner profiles. Fixed to dedicated vertical brackets, never into the board itself.

Prices for installed composite cladding

2026 price ranges (labour included)

For a house with 140 m2 of facade

• Cedral Click fibre cement installed by a contractor: 17,000 to 22,500 €
• Cedral Click as a self-build (boards + clips + aluminium subframe + membrane + accessories): 9,500 to 13,000 €
• Self-build saving: 7,500 to 9,500 € on this item

Decision tree: which non-timber cladding to choose?

Common mistakes to avoid

1. Timber batten subframe under composite cladding — clips pull out, boards blister within two summers
2. Forgetting the end expansion gap — board bows or splits
3. Over-tightening clips — board cannot slide, same result
4. Galvanised steel fixings instead of stainless — rust streaks down the facade
5. Gluing boards with sealant to “reinforce” — expansion is blocked, the system fails
6. No breathable membrane because “it’s waterproof anyway” — condensation in the insulation, rot in the timber subframe under EWI
7. Rails not plumb — cumulative error, boards misaligned by several cm at the top
8. Cavity inlet blocked by landscaping backfill after completion — no ventilation, mould within a year
9. Choosing cellular uPVC on a south-facing elevation with a dark colour — guaranteed warping within one summer
10. Buying clips from one brand for boards from another — incompatible dimensions, cladding rattles

Standards and references

• French DTU 41.2 / RAGE rules (equivalent to UK BS 8000-8 or BBA certification) — Covers timber-based and WPC rainscreen cladding
• French RAGE 2015 professional rules (equivalent to BBA certification) — References for fibre cement and metal rainscreen cladding
• NF EN 12467 — Flat fibre-cement sheets for exterior cladding
• CSTB Technical Approvals — Every composite system sold in France must hold a CSTB ATec (request it from the manufacturer). CSTB (French technical approvals body, similar to BBA in the UK)
• SNFA — French facade industry association: technical resources for rainscreen cladding

Checklist before you start

Useful links

• Warm traditional alternative: our guide to timber cladding — boards, battens and breathable membrane
• Mineral alternative without cladding: monocouche render for a through-coloured finish
• Composite cladding is often installed over external wall insulation — the two combine naturally
• For opening details under cladding, see window sills and external thresholds
• Understanding membranes: breathable membranes, vapour barriers and vapour retarders — the roles explained