The Rockwool Full Fill Cavity Batt is a semi-rigid stone wool insulation slab designed for superior thermal, acoustic, and fire performance in masonry cavity walls. Fully filling the cavity without the need for air gaps, it provides consistent insulation, enhanced energy efficiency, and excellent moisture resistance.

Benefits

Delivers excellent thermal insulation with a low thermal conductivity of 0.037 W/m·K, helping to reduce heat loss and improve energy efficiency
Euroclass A1 non-combustible, providing the highest level of fire safety and peace of mind
Water-repellent yet breathable, allowing moisture vapour to pass through while preventing water ingress
Semi-rigid batts fit snugly between wall ties, ensuring a continuous insulation layer with minimal gaps
Provides effective acoustic absorption, reducing sound transmission through external and separating walls
Durable and dimensionally stable, maintaining performance throughout the lifetime of the building
Manufactured from natural volcanic rock and recycled materials, supporting sustainable and environmentally responsible construction

Good to Know

Suitable for use in new build external masonry cavity walls and party wall applications
Can be used in buildings up to and including 12 metres in height in England and Wales, and up to 25 metres in Scotland (check local regulations)
Available in a range of thicknesses
Easily cut using a utility knife; wear gloves and a dust mask when cutting in unventilated areas
Store under cover, off the ground, avoiding prolonged exposure to sunlight and rain
Specialist PPE is not required, though a dust mask is recommended if cutting in unventilated areas

50mm Wall Insulation

50mm Rockwool Full Fill Cavity Batt 1.2m x 455mm (6.55m2)