Rockwool Installations

Rockwool stone wool insulation is one of the primary infill materials in the commercial dry lining and partition systems we install. It sits inside the cavity of a metal stud partition or behind a plasterboard lining, performing two roles simultaneously: limiting sound transmission between rooms (acoustic performance) and resisting the spread of fire and heat through the assembly (fire performance). The insulation is not a visible element in the finished interior, but it is the component that determines whether the partition achieves its rated EI and Rw performance.

Who is Rockwool?

Rockwool is a Danish manufacturer and part of the ROCKWOOL Group, established in 1937 and headquartered in Hedehusene, Denmark. The group is the world's largest manufacturer of stone wool, operating production plants across Europe, North America and Asia. Stone wool is produced by melting basalt rock and recycled material at high temperature and spinning the molten material into wool fibres, which are then compressed, bound and cut into slabs, rolls and boards of varying density and thickness.

The ROCKWOOL Group owns two principal product brands that we work with in commercial fit-out. Rockwool is the insulation brand, supplying stone wool products for partition cavities, ceiling voids, acoustic build-ups and thermal insulation applications. Rockfon is the acoustic ceilings brand, supplying stone wool ceiling tiles, free-hanging rafts, baffles and monolithic ceiling systems. The two brands share the same parent and the same core material but serve entirely different applications within a building.

Rockwool and Rockfon: a clear distinction

This point is worth making explicitly because the two brands are sometimes conflated. Rockwool products go inside the construction assembly, hidden within the partition cavity or above the ceiling tile, where they contribute acoustic absorption and fire resistance. Rockfon products are the finished ceiling surface, providing acoustic absorption at the room level and contributing to the aesthetic of the space. Specifying Rockfon acoustic ceiling tile and Rockwool partition cavity insulation on the same project is common and correct: they are complementary products from the same group performing different functions.

Our Rockfon manufacturer page covers the acoustic ceiling tile range we install. This page covers Rockwool insulation only.

Where Rockwool insulation sits in our assemblies

Partition cavities are the primary application. In a standard commercial metal stud partition, the cavity between the two plasterboard faces is filled with stone wool insulation to achieve acoustic separation between rooms. The Rockwool RW3 Flexi Slab is the standard infill product for non-rated and standard acoustic partitions. For partitions requiring higher Rw performance or specific tested assembly specifications, the RWA45 or Sound Slab products are selected from the system document for the target rating and assembly configuration.

Fire-rated partition assemblies require infill density and thickness that matches the manufacturer's tested system document. The Euroclass A1 fire classification of Rockwool stone wool means the infill makes no contribution to fire development, which is a requirement for products used in fire-rated compartment walls.

Ceiling voids are a secondary application. Where the acoustic brief for a room requires supplementary absorption above a suspended ceiling tile, Rockwool RWA45 in roll format can be laid on top of the ceiling tile within the void. This is most commonly specified where the ceiling tile itself does not provide sufficient acoustic mass for the room's reverberation target, or where flanking sound transmission through the ceiling void is a concern in high-performance acoustic assemblies.

Compliance

Rockwool stone wool achieves Euroclass A1 reaction-to-fire classification under EN 13501-1, confirming it is non-combustible and produces no contribution to fire or smoke in a fire. The product contributes to the tested fire and acoustic performance of partition assemblies when installed to the density, thickness and configuration specified in the manufacturer's system document. We confirm the Rockwool product specification against the tested assembly at pre-construction on every fire-rated and acoustic build.

Sectors where Rockwool is specified

Education environments require fire-rated compartment walls between teaching spaces, acoustic separation between classrooms, and often the highest levels of both: high-performance acoustic stud partitions rated EI 60 or above carry Rockwool Sound Slab in the cavity. Healthcare has equivalent demands, with acoustic consultation rooms, clinical compartmentation, and stringent fire performance requirements. Commercial offices use Rockwool RW3 as the default acoustic infill in meeting room, cellular office and open-plan demising walls. Industrial fit-out uses Rockwool in the office, welfare and control room partitions that sit within the wider industrial structure.

Get in touch

If you are specifying a project where partition acoustic or fire performance is a design consideration, we would be glad to discuss the brief. Send drawings or the acoustic consultant's target Rw values with the form on this page and we will come back with a clear next step within one working day. For urgent enquiries call 01332 757830 or email enquiries@eastledge.co.uk.