Rockwool Cavity Wall Insulation 1200mm x 455mm Pack

ROCKWOOL Full Fill Cavity Wall Insulation

ROCKWOOL Full Fill Cavity Wall Insulation is a high-performance stone wool insulation designed specifically for masonry cavity wall constructions. Suitable for new-build properties and extensions, the semi-rigid insulation batts provide effective thermal performance while also offering excellent fire resistance, moisture resistance and long-term durability.

Manufactured from ROCKWOOL stone wool, the cavity batts are designed to fit closely between the inner and outer leaves of a masonry cavity wall. The slabs are supplied at 455mm wide, allowing them to fit standard vertical wall tie spacings and helping create closely fitted joints between adjoining batts.

Effective Thermal Insulation

ROCKWOOL Full Fill Cavity Batts have a declared thermal conductivity of 0.037 W/mK, helping reduce heat transfer through external masonry walls and improve the overall thermal performance of the building.

Correctly insulating cavity walls can help reduce heat loss and create a more comfortable indoor environment. This makes ROCKWOOL cavity wall insulation an excellent choice for both new construction and extension projects where improved energy efficiency is required.

The semi-rigid stone wool construction allows the insulation to fit closely against brick and blockwork, helping minimise unwanted gaps that could otherwise reduce insulation performance.

Full Fill Cavity Wall Insulation

ROCKWOOL Full Fill Cavity Batts are designed to completely fill suitable masonry wall cavities. Their semi-rigid construction makes the slabs easy to handle while allowing them to be friction fitted closely together.

The 455mm slab width is specifically designed around common wall tie spacings, helping installers achieve neat joints and continuous insulation throughout the wall construction.

Unlike some rigid insulation materials, the flexible stone wool fibres can accommodate minor imperfections within the wall construction, helping maintain close contact with the blockwork and reduce gaps.

Non-Combustible Stone Wool

Fire performance is another major benefit of ROCKWOOL Full Fill Cavity Wall Insulation. The product achieves a Euroclass A1 reaction to fire classification, the highest level of non-combustibility under EN 13501-1. ROCKWOOL states that the stone wool material can withstand temperatures exceeding 1,000°C.

This makes it a suitable choice for projects where fire safety forms an important part of the overall wall specification.

Combining thermal insulation and non-combustible performance in a single product can help simplify the construction of high-performing masonry cavity walls.

Water Repellent Properties

Cavity walls can be exposed to moisture entering through the external masonry, particularly during prolonged periods of wind-driven rain. ROCKWOOL Full Fill Cavity Batts incorporate an additive designed to support the product’s water-repellent properties.

The insulation is designed to resist the transfer of moisture across the cavity when correctly installed as part of a properly constructed masonry wall.

ROCKWOOL Full Fill Cavity Batt is also BBA certified for full-fill applications, subject to the exposure-zone and construction limitations set out within the certification.

Durable and Easy to Install

ROCKWOOL stone wool is dimensionally stable and designed to retain its shape and thickness over time. This helps reduce the risk of insulation slumping or sagging within the cavity and contributes towards consistent long-term performance.

The slabs are lightweight and straightforward to handle on site, making them suitable for professional building and renovation projects. Their semi-rigid construction allows them to be cut where necessary and fitted closely around wall ties and other building details.

Reliable Cavity Wall Insulation

Whether you are constructing a new property or insulating the cavity walls of an extension, ROCKWOOL Full Fill Cavity Wall Insulation provides a reliable combination of thermal performance, fire protection, water resistance and long-term durability.

With a thermal conductivity of 0.037 W/mK, Euroclass A1 non-combustibility and a practical semi-rigid slab format, ROCKWOOL Full Fill Cavity Batts offer a dependable solution for creating well-insulated masonry cavity walls.

Product Specifications