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SOFFITCLAD® Plain stone wool insulation board

SOFFITCLAD®Plain

Soffit Applications

A high-performance, unfaced A1 stone wool insulation board for concealed soffits, built-up ceiling assemblies, and core structural decks.

100
Nominal density
0.0364
W/mK conductivity
50–220
Thickness range (mm)
A1 Fire Rated — Euroclass A1 Non-Combustible
BBABDA AgrémentKiwa

Product description

Soffitclad® Plain is an unfaced, non-combustible stone wool insulation board designed for use within concealed soffits, core structural decks, and built-up ceiling applications. Manufactured from volcanic basalt rock, Soffitclad Plain provides reliable thermal insulation, fire resistance, and acoustic absorption within enclosed ceiling zones and structural service areas. The raw, unfaced finish is ideal for applications where the insulation layer will be covered by secondary cladding or decorative ceiling panels. With a structural nominal density of 100 kg/m³ and a declared thermal conductivity of λ = 0.0364 W/mK, Soffitclad Plain delivers high-performance thermal protection along with exceptional acoustic performance. This insulation board carries a premium Euroclass A1 fire rating, rendering it entirely non-combustible and certified for multi-story residential and commercial building configurations requiring maximum safety compliance.

Euroclass A1 (non-combustible) in accordance with BS EN 13501-1 reaction to fire
Declared thermal conductivity 0.0364 W/mK
Nominal density 100 kg/m³

Application

SOFFITCLAD®Plain is specified across Soffit Applications constructions. Typical application areas include:

Concealed concrete soffits and hidden core structural floor slabs
Enclosed ceiling voids and structural interstitial service zones
Built-up ceiling assemblies requiring a secondary finished panel layer
Core thermal floor linings behind decorative cladding or suspended grid systems
Hidden structural configurations requiring raw high-density thermal cores
Buildings of any height requiring unseen A1 non-combustible overhead insulation

Documentation

Datasheets, Declarations of Performance, BIM files and certificates for SOFFITCLAD®Plain are available on request from our technical team.

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Product properties

NameValueUnit
Reaction to fire (Euroclass)A1 — non-combustible
Classification standardBS EN 13501-1
Nominal density100kg/m³
Declared thermal conductivity (λD)0.0364W/mK
Thickness range50–220mm

Full property schedule (water absorption, vapour resistance, compressive strength, dimensional stability) available on request.

Product variants

Product codeThickness (mm)Width (mm)Length (mm)Pieces / pallet (pcs)m² / pallet (m²)
TWSP100050 50 6001200 40 57.6
TWSP100130 130 6001200 20 21.6
TWSP100160 160 6001200 16 17.28
TWSP100180 180 6001200 16 11.52
TWSP100200 200 6001200 12 8.64
TWSP100220 220 6001200 12 8.64

Case study

Project references and case studies featuring SOFFITCLAD®Plain are available on request.

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Speak to an expert

Our technical team can help you specify SOFFITCLAD®Plain for your project.

Phone: 020 3949 8826
Email: [email protected]

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Find a stockist

Locate your nearest Thermawool stockist or distributor for availability and lead times across the UK.

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Our locations

Head Office
1 Bedlam Mews, London, SE11 6DF

Warehouse
Unit 1, Mirravale Estate, Dagenham, RM8 1YY

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Specifying SOFFITCLAD®Plain on your project? Our technical team is here to help.