Spray Cork Insulation in the UK — The Complete 2026 Guide

Spray cork insulation is a flexible 3–6 mm coating made from natural cork granules, water-based resins and mineral pigments. Applied by HVLP spray, it bonds to brick, render, pebbledash, timber, uPVC and concrete to form a single breathable thermal layer that doubles as a long-life external finish.

How spray cork insulation actually works

Cork's cellular structure traps millions of microscopic air pockets — the same physics that makes it the world's most efficient natural insulator. When sprayed in two cross-coats, it raises the wall's thermal resistance by up to 30%, bridges hairline cracks up to 2 mm, and lets water vapour pass through so the substrate behind stays dry.

What does spray cork cost in the UK?

As of 2026, accredited UK installers price spray cork exterior wall coatings at roughly £75–£120 per m² supplied and installed. A typical three-bedroom semi (around 110 m² of wall) lands between £8,500 and £12,000 including scaffolding, prep, two coats and warranty registration.

Is it cheaper than EWI?

External wall insulation (EWI) using EPS or mineral wool boards typically runs £140–£200 per m² before finish. Spray cork delivers a meaningful U-value improvement at roughly half the cost, in a fraction of the time, and without losing any window reveals or detailing.

Planning permission and building regulations

For most properties, spray cork is treated as a redecoration and does not require planning permission. Listed buildings and conservation areas need consent, and local authorities are generally supportive because the coating is breathable and reversible. Building regulations are not triggered unless the coating is part of a wider thermal upgrade scheme.

Warranty and lifespan

Installed by an accredited applicator, the CorkSol system carries a 25-year manufacturer warranty against cracking, flaking and colour fade. Independent test data and Spanish in-service buildings suggest a working life of 40+ years before recoating.