Composite and insulated cladding panels
Composite sandwich panels combine a pre-finished steel outer skin, an insulation core, and a steel liner in a single factory-made unit. They are the standard cladding choice for UK portal frame buildings where thermal performance, build speed, and weathertightness are critical. Data is sourced from manufacturer technical data sheets and public product information.
| Product | Core | λ (W/mK) | Width (mm) | Min pitch (°) | Use | Fire reaction | |
|---|---|---|---|---|---|---|---|
|
Kingspan QuadCore KS1000RW | QuadCore PIR | 0.018 | 1000 | 4° | Roof / Wall | B-s1,d0 (BS EN 13501-1), Class 0 … | |
|
Kingspan QuadCore KS1000 LP | QuadCore PIR | 0.018 | 1000 | 1.5° | Roof | Broof(t4) to BS EN 13501-5 | |
|
Kingspan KS1000 FF | K-Roc mineral wool | 0.043 | 1000 | — | Roof | A2-s1,d0 (non-combustible) | |
|
Kingspan QuadCore Topdek | QuadCore PIR | 0.018 | 1000 | 0.72° | Roof | — | |
|
Steadmans AS35 Multi | PIR | 0.022 | 1000 | 4° | Roof / Wall | C-s1,d0 to BS EN 13501-1 (indicat… | |
|
Tata Steel Trisomet | PIR or mineral wool | — | 1000 | 4° | Roof / Wall | — |
Common questions
What is a composite cladding panel?
A composite cladding panel (also called a sandwich panel) consists of two pre-finished steel facings bonded to an insulation core under factory conditions. The core is either PIR (polyisocyanurate) or mineral wool. The finished panel provides the outer weatherskin, thermal insulation, and inner liner as a single installed element, which reduces site labour compared with built-up systems.
What is the difference between PIR and mineral wool core panels?
PIR panels achieve lower U-values at thinner overall depths — typically lambda values of 0.018–0.022 W/mK compared with 0.038–0.043 W/mK for mineral wool — making them the dominant choice where thermal performance or headroom is important. Mineral wool panels have non-combustible A2 fire classification under BS EN 13501-1, which is required for buildings above 18m and certain other fire engineering situations.
What U-value is required for portal frame roof cladding?
UK Building Regulations Part L (2021 edition, effective April 2023) sets maximum U-values for non-domestic new builds. Roof U-values are typically limited to 0.25 W/m²K and wall U-values to 0.35 W/m²K, though notional building calculations may require tighter values. Panels in the 80–100mm core range typically achieve roof U-values of 0.20–0.25 W/m²K with PIR core. Always confirm against the current approved document or your SAP/SBEM assessment.
What does UKCA marking mean for composite panels?
UKCA (UK Conformity Assessed) marking replaced CE marking for construction products placed on the Great Britain market from 1 January 2025. It covers structural performance, thermal properties, fire reaction, and air permeability. Products sold into Northern Ireland still require CE marking. Always request the current Declaration of Performance from the manufacturer.