All systems
Technical sheet
A.01A.02
SystemS-41

Cork ETICS

External insulation with expanded cork (ICB) boards: a natural closed-cell insulant, water-repellent and rot-proof, bonded and anchored to the wall, base-coated with mesh and finished with mineral render. Unlike fibrous insulants it neither fears water nor distorts with humidity: it is dimensionally stable, breathable and of renewable plant origin, suited even to the plinth and the most exposed zones. It is the most durable and robust bio choice.

Isolamento a cappotto (ETICS)Hydrophobic bio-based external insulation
B.01
System build-up6 layers
INTERNOESTERNO1. Parete2. Collante3. Pannello in sughero4. Rasatura + rete5. Intonaco minerale6. TinteggiaturaTassello

Technical section of the system, from inside (left) to outside (right).

Hydrophobic bio-based external insulation
Spessore dell'isolante
6-16cm
Conduttività λ
0,040-0,045W/mK
Densità del pannello
110-160kg/m3
Sfasamento termico
8-12h
Reazione al fuoco
E
Assorbimento d'acqua
molto basso
Descriptive memo

External insulation with expanded cork (ICB) boards: a natural closed-cell insulant, water-repellent and rot-proof, bonded and anchored to the wall, base-coated with mesh and finished with mineral render. Unlike fibrous insulants it neither fears water nor distorts with humidity: it is dimensionally stable, breathable and of renewable plant origin, suited even to the plinth and the most exposed zones. It is the most durable and robust bio choice.

Cork ETICS is an external insulation system in which the insulant is a board of expanded cork (ICB), made from the bark of the cork oak expanded and bound by its own resin, with no glues. The laying follows the system's logic — bonding, anchoring, reinforced base coat, finish — but the material brings two rare qualities: water resistance and dimensional stability.

Water-repellent and rot-proof

Cork's closed cells, impregnated with suberin, repel water: the board does not absorb moisture, does not rot and is not attacked by mould or insects. This is why cork is used even where fibrous insulants fear getting wet — the plinth, splash zones, risky details — staying efficient over time.

Stable and breathable

Cork is dimensionally stable: it does not swell with humidity nor shrink, so the base coat above cracks less at the joints. It also stays vapour-open, letting the wall «breathe», and gives good acoustic insulation thanks to its cellular structure. The finish must remain mineral and breathable so its quality is not lost.

Laying and fire

Heavier and stiffer than synthetic boards, cork needs suitable adhesives and anchors and a careful reinforced base coat. It is a combustible material (class E): on façades, especially on tall buildings, the fire rules must be met with non-combustible bands and details. Otherwise it follows the system's rules: corner beads, drips, mesh embedded in the outer third.

Systems architecture

Why it works

Water-repellent and dimensionally stable
cork: sheds, stays stablefibrous: soaks, swellscork’s closed, waxy cells repel water: it does not rot or swell— stable under the render, usable even at the plinth

Cork’s quality lies in its closed cells, impregnated with waxy suberin: water does not get in. Where a wetted fibrous insulant soaks up water, swells and may eventually rot, cork repels it, keeps its volume and stays sound — which is why it is used even at the plinth and in rain-beaten zones. Being dimensionally stable it does not «push» on the base coat, which then cracks less at the joints; and staying vapour-open it lets the wall breathe.

Water resistance of ETICS insulants

Comparison · insulants
Cork
negligible
XPS
very low
EPS
low
Fibrous (wood / mineral)
hygroscopic

Longer bar = the less water it takes up, the more it can work in damp and exposed zones. Cork barely absorbs and does not rot, so it can run down to the plinth.

Nodal details

Critical junctions · sections
123456
D.01
Water-repellent plinth

The system starts on a starting profile with a drip; because cork is water-repellent the boards can run right down to the plinth, where a reinforced band (double mesh) takes the knocks and the splashing. No separate moisture-sensitive plinth board is needed.

  1. Wall
  2. Starting profile (with drip)
  3. Cork board
  4. Reinforced base coat
  5. Reinforced plinth band
  6. Render + finish
123456
D.02
Anchoring and base coat

Cork boards are heavier than synthetic ones, so anchors matter: dowels are set after the adhesive has cured and capped with a flush cork plug, so they make no thermal bridge. Over them the mesh is embedded in the outer third of the base coat.

  1. Cork board
  2. Adhesive
  3. Concealed dowel (cork plug)
  4. Reinforcing mesh
  5. Base coat
  6. Finish render

Installation controls

Specification · checklist

01 · Substrate

Sound, clean, flat wall
Moisture content checked
Adhesion / pull-off test

02 · Bonding & fixing

Adhesive coverage
Dowels after curing, capped
Pattern to the wind load

03 · Base coat

Mesh in the outer third
Double mesh at openings
No mesh showing through

04 · Render & finish

Mineral, breathable render
Even thickness
Weather window respected

05 · Fire & plinth

Fire bands at floors (tall buildings)
Reinforced plinth band
Drips and corner beads

Recurring defects

Diagnostics · site
Meccanica
Cracking of the base coat
CauseThermal movement at board joints and openings, or a thin / badly placed base coat, opens cracks — even if the cork itself is stable.
PreventionMesh in the outer third, double mesh at openings, staggered boards, an elastic mineral base coat.
Adesione
Detachment of the boards
CauseCork boards are dense and heavy: a dusty substrate, too little adhesive or anchors set too early let them detach and bulge.
PreventionSound prepared substrate, adhesive coverage, dowels after curing, anchor number and pattern to the wind load.
Termica
Dowel ghosting (thermal bridges)
CauseMetal anchors left uncapped or set proud conduct heat and draw damp and dirt: a regular pattern of spots «maps» on the façade.
PreventionRecessed dowels with flush cork plugs, the right anchor type, enough base-coat cover over the heads.
Sicurezza al fuoco
Façade fire behaviour
CauseCork is combustible (class E): on tall buildings an unbroken organic insulation can spread fire up the façade.
PreventionNon-combustible fire bands at the floors, mineral details around openings, design to the fire code for the building height.

Component materials

The network · materials