75mm Rockwool RWA45 Acoustic Sound Insulation Slab (4.32m2/Pack)

Product Overview

Stone wool insulation slab, measuring 75mm in thickness, designed for use in internal partitions, floors, and roof applications.

Manufactured from high-density stone wool, the slab combines excellent acoustic absorption with reliable thermal insulation and inherent fire resistance. 

Its rigid composition allows a close friction fit between studs or joists, preventing gaps that could compromise performance.

Non-combustible and classified as Euroclass A1, the slab contributes to improved fire safety within the building fabric. Its fibre structure also provides effective sound reduction, limiting noise transfer between rooms and floors.

At 75mm thick, the slab offers a versatile mid-range option within the RWA45 range. 

It is commonly specified in residential and commercial partitions where higher acoustic performance is needed than thinner slabs can deliver, but without the full depth of 100mm. 

Features & Benefits

• Euroclass A1 fire classification: Non-combustible in accordance with BS EN 13501-1.
• Stone wool mineral slab: Naturally resistant to rot, fungal decay, and insect attack.
• Square-cut edges: Butt together cleanly for continuous insulation layers.
• Porous fibre structure: Absorbs sound energy, reducing noise transfer through walls and floors.
• Semi-rigid slab: Simple to shape with a knife and friction-fit between studs or joists.
• Thermal conductivity 0.035 W/m·K: Helps maintain building energy efficiency.
• Sustainable manufacture: Made from natural volcanic rock, recyclable, zero ODP/GWP.
• 75mm thickness: For walls and floors requiring strong sound insulation alongside reliable fire and thermal benefits.
  
  

Applications

• High-performance stud partitions: Strong sound insulation for demanding builds.
• Separating floors in multi-occupancy housing: Significantly reduces airborne noise.
• Ceilings in noisy environments: Provides robust acoustic control.
• Drylined wall systems: Adds substantial acoustic and thermal upgrade.
• Home studio soundproofing: 75mm profile provides low-frequency absorption for deep-cavity wall installations in recording environments.
• HMO internal partitions: Mineral wool construction ensures higher sound attenuation within domestic stud walls to meet stringent residential privacy standards. 
• Home cinema rooms: Slabs provide dampening of low-frequency vibrations within wall cavities to prevent audio bleed into adjacent spaces.

Installation Guidance

• Precision cutting: Use a sharp insulation saw or broad-bladed knife to cut slabs slightly oversized to ensure a compressed friction fit.
• Seamless abutment: Butt all joints tightly together with no visible gaps to maintain the continuity of the fire and acoustic barrier.
• Mechanical support: Secure with appropriate netting or insulation hangers when installing in overhead applications to prevent gravity-induced movement.
• Environmental protection: Store slabs undercover and off the ground to ensure the material remains dry and free from contaminants prior to installation.
• Personal protection: Wear loose-fitting clothing, gloves, and safety goggles to minimise skin and eye contact with mineral fibres.

Soundproofing Guidance

• Mass Enhancement: Combine slabs with high-density soundproof plasterboard to significantly increase the total mass of the partition. 
• Decoupling Strategy: Use resilient bars or independent stud frames in conjunction with the slabs to prevent mechanical vibration from traveling through the structure.
• Acoustic Sealing: Apply acoustic sealant to the perimeter of the partition and around any penetrations to prevent "flanking" noise from bypassing the insulation.
• Cavity Management: Ensure the slab fills at least 75% of the cavity depth to provide optimal sound absorption and prevent internal resonance.

Compliance & Performance

• Thermal conductivity: Declared 0.035 W/m·K (EN 13162).
• Fire performance: Euroclass A1 non-combustible (BS EN 13501-1).
• Certification: CE and Key marked to BS EN 13162:2012 + A1:2015.
• Acoustic standards: Supports compliance with Building Regulations Approved Document E (England & Wales), Section 5 (Scotland), and BB93 (schools) for acoustic performance in internal and separating walls/floors.
• Sound Absorption Class: Achieves Sound Absorption Class A (aw 1.00). Delivers maximum acoustic absorption across the full frequency spectrum (NRC 1.00).
• Marine/offshore certification: Lloyd’s Register approved as non-combustible.