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A high performance, dual-density, fleece-faced stone wool insulation board for warm flat roofs. Suitable for use with most types of roof deck, and all roof covering types – torch, pour-and-roll, single ply, EPDM, liquid applied, and green roofs. Suitable for new build and refurbishment, Hardrock Multi-Fix Dual Density roofing boards are strong enough to bear normal foot traffic associated with installation and routine maintenance inspections of the roofing system. ROCKWOOL Hardrock is CE and Key marked in accordance with BS EN 13162. Non-combustible, achieving a classification of A1 in accordance with BS EN 13501-1. ROCKWOOL insulation products do not contain blowing agents with an ozone depletion potential (ODP) or global warming potential (GWP), are CFC-HCFC-HFC free and 97% recyclable. They will not react with metal components or cause loss of plasticizer from PVC cables and pipes.


  • Euroclass A1 non-combustible.
  • Both LPCB approved (LPS 1181: Part 1 Ext A) and FM approved.
  • Excellent acoustic reduction, absorption and impact (rain noise) performance.
  • Dimensionally stable providing a long term, consistent thermal performance.
  • Can be recycled and reprocessed reducing landfill costs, zero ODP and GWP.
  • Compatible with numerous roof finishes.

General information
Specification data
Product Reference

ROCKWOOL Hardrock Multi-fix DD





60 mm

85 mm

105 mm

115 mm

150 mm

170 mm

185 mm

Standard product features

Slab size:

1200 x 1000 mm.

Thermal conductivity:

0.039 W/mK.

Reaction to fire class:

A1 to BS EN 13501-1.

Product Options

Standards and approvals:

HARDROCK® Multi-Fix (DD) roofing boards have been assessed by the British Board of Agrement to UEAtc technical guidelines MOAT No 50: 1992 ‘Thermal insulation systems intended for supporting waterproof coverings on flat and sloping roofs’.

They have also been tested for the effects of mechanical stress, and have achieved classification C ‘Roof accessible to pedestrian traffic and may be used where frequent maintenance of equipment is envisaged’.

Factory Mutual:

Approval report JI 3015604: Approved for Class 1 insulated roof deck constructions.


  • BS 476: 21 – 60-120 minutes load-bearing fire resistance (depending on thickness) (cert. 022a).
  • BS EN 13501-1 – Class A1 Non-combustible (cert. 022e).
  • LPS 1181: 1 EXT-A60, A90 or A120 (depending on thickness) and EXT-B (cert. 022g).

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