RWA45 Rockwool Slab Insulation- All Thicknesses

Description

Rockwool RWA45 is a semi-rigid stone wool slab at a density of 45kg/m³, used for acoustic, thermal and fire insulation in partition walls, floors, ceilings and roofs. It is the most specified acoustic slab in the UK: the dense fibre structure absorbs airborne sound between rooms and floors, while as a stone wool product it is Euroclass A1 non-combustible with a melting point above 1000°C. The semi-rigid slab friction-fits between studs and joists at 600mm or 400mm centres, so it stays put without fixings. In stock at our Rossendale warehouse for next-day UK delivery or trade counter collection.

Thicknesses and R-values

All slabs are 1200 x 600mm. RWA45 has a thermal conductivity of 0.035 W/mK.

Pack quantities and coverage vary by batch — check the option you need on the product page. All also available by the pallet.

What is RWA45 used for?

The name tells you what it is: RW for Rockwool, A for Acoustic, 45 for the 45kg/m³ density. That density is what makes it the go-to for soundproofing.

• Stud partition walls — the most common use. 100mm between the studs cuts airborne sound between rooms. 50mm and 25mm suit shallower partitions.
• Intermediate floors — between joists to reduce sound transfer between storeys.
• Ceilings and roofs — thermal and acoustic insulation above or below rafters.
• Fire compartmentation — as an A1 non-combustible slab, it helps maintain fire-resistant lines in walls and floors.

RWA45 is not designed for filling external brick-and-block cavity walls — use a cavity slab such as DriTherm or a cavity batt for that. If you are not sure which product the job calls for, call us and we will point you to the right one.

Which thickness do I need?

For soundproofing a stud wall or floor, 100mm gives the best acoustic performance and is the most specified. Where depth is limited, 50mm still makes a worthwhile difference. For thermal insulation between studs, thickness follows the U-value you are working to — send us the build-up and we will calculate it. Note that mineral wool needs more thickness than PIR to reach the same U-value, so if space is tight and sound is not the priority, a PIR board may suit better.

Specification

• Thermal conductivity: 0.035 W/mK
• Density: 45kg/m³
• Reaction to fire: Euroclass A1, non-combustible (BS EN 13501-1)
• Slab size: 1200 x 600mm
• Water-repellent, rot-proof and does not support mould or vermin
• CE marked to EN 13162, zero ODP and GWP
• Semi-rigid — cut to size with a sharp insulation knife

Buying from Pinks

Full range of thicknesses in stock, with pallet quantities at trade prices, next-day UK delivery and collection from our trade counter in Crawshawbooth, Rossendale. We also stock Rockwool RW3 for higher-density applications and the full range of acoustic partition rolls if you are soundproofing a larger area.