Rockwool Hardrock Multi-Fix Recovery Board

The Rockwool Hardrock Multi Fix Recovery Board, manufactured for flat roofs refurbishment in both commercial and domestic building projects. The Hardrock Multi-Fix Recovery Board is non-combustible, has a thermal conductivity of 0.039w/mK, has a water vapour resistance of 5.9 MNs/gm and is compatible with all commonly-used flat roof membranes including, bitumen, EPDM, single ply, and liquid-applied systems.

*Always Refer Back To The Manufactures Specification Document 

Download Specification

HARDROCK® Multi-Fix Recovery Board has been specifically developed for use on flat roof refurbishment projects.

HARDROCK® Multi-Fix Recovery Board is manufactured with an integral mineral coated glass fibre fleece, which for adhered membranes, secures a strong bond between membrane and insulation whilst limiting the amount of adhesive required.

HARDROCK® Multi-Fix Recovery Board is compatible with all commonly used flat roof membranes including.

• Single-Ply & EPDM
• Bitumen membranes
• Liquid membrane systems

Applications HARDROCK® Multi-Fix Recovery Board is suited to:-

• Domestic refurbishment
• Commercial refurbishment
• Up stand details

HARDROCK® Multi-Fix Recovery Boards are completely fire safe and can be used to provide an effective acoustic barrier  to external noise pollution.

Acoustic performance

When tested in accordance with BS EN ISO 10140-2:2010 HARDROCK® MultiFix Recovery Board has proven that it can improve the acoustic performance of a typical flat roof system by up to 25%.

When installed above a typical warm flat roof system consisting of 100mm PIR onto a 0.7mm profiled steel deck, the airborne sound reduction performance was increased from *Rw 28dB to **Rw 35dB.

When tested as an individual 30mm layer within a single ply flat roof system, onto a 0.7mm profiled steel deck, the system performance achieved ***Rw 33 dB.

HARDROCK® Multi-Fix Recovery Board is the ideal solution for flat roof refurbishment on schools and supports the current acoustic refurbishment standards as listed in Table 1 of the Building Bulleting 93 document, “Acoustic Design of Schools: Performance Standards.”


Warm roofs and cold ventilated roofs HARDROCK® Multi-Fix Recovery Board has been specifically developed for use on flat roof refurbishment projects.

• Remove any loose debris.

• Mechanically fix or bond HARDROCK® Multi-Fix Recovery Board through/to the existing roofing membrane and/or insulation, into the roof deck, always ensuring that the existing deck is in a reasonable condition. A compatible adhesive must be used for bonding the insulation to the existing surfaces.

• 4N° fixings per m² are required (5N° per board) for all bonded and torch applied membranes (see recommended installation section containing fixing pattern, below).

• For all applications the boards should be laid in a staggered pattern with the mineral fleece facing upwards.

• Apply the new membrane to HARDROCK® Multi-Fix Recovery Board (see fixing guidelines overleaf).

• The existing cross ventilation of cold roof systems must always be maintained.

Health & Safety

The safety of ROCKWOOL stone wool is confirmed by current UK and Republic of Ireland health & safety regulations and EU directive 97/69/EC:ROCKWOOL fibres are not classified as a possible human carcinogen.

A Material Safety Data Sheet is available and can be downloaded from to assist in the preparation of risk assessments, as required by the Control of Substances Hazardous to Health Regulations (COSHH).


Made from a renewable and plentiful naturally occurring resource, ROCKWOOL insulation saves fuel costs and energy in use and relies on trapped air for its thermal properties.

ROCKWOOL insulation does not contain (and has never contained) gases that have ozone depletion potential (ODP) or global warming potential (GWP). ROCKWOOL is approximately 97% recyclable.

For waste ROCKWOOL material that may be generated during installation or at end of life, we are happy to discuss the individual requirements of contractors and users considering returning these materials to our factory for recycling.

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