Fixing and buying guide

What this product is and who it is for

Dritherm Cavity Slab 32 Ultimate is a rigid cavity wall insulation slab manufactured from glass mineral wool. It is designed for builders, contractors, and experienced DIY installers working on cavity wall insulation projects. The product is suitable for both new build construction and retrofit applications where cavity widths accommodate the 150mm thickness. It provides thermal insulation, fire resistance, and acoustic benefits, making it a standard choice for meeting current Building Regulations energy efficiency requirements.

Compatibility and sizing

This product is designed for cavity walls with a minimum cavity width of 150mm. Each slab measures 1200 x 455 x 150mm, allowing flexible placement within the cavity. The rigid format means slabs can be cut to fit around obstacles such as wall ties and cavity closers. Ensure your cavity width is adequate before purchase. For cavities wider than 150mm, you may need to use thicker slabs or combine products. Check your building design and cavity specifications before ordering.

• Slab dimensions: 1200 x 455 x 150mm
• Pack contains four slabs
• Total coverage per pack: 2.184 square metres
• Suitable for 150mm cavity widths
• Thermal conductivity: 0.032 W/mK

Pack contents and coverage

Each pack contains four rigid slabs of Dritherm Cavity Slab 32 Ultimate. The four slabs together provide 2.184 square metres of wall coverage. Calculate your total cavity wall area and divide by 2.184 to determine the number of packs required. Account for waste and cutting around openings such as windows and doors. Order slightly more than your calculated requirement to allow for fitting adjustments and site wastage.

• Four slabs per pack
• 2.184 square metres coverage per pack
• Rigid format for easy handling and placement
• Suitable for cutting to fit around obstacles

Pre-installation checks and preparation

Before installation, inspect the cavity to ensure it is clear of debris, mortar droppings, and obstructions. Verify that cavity width is a minimum of 150mm and that wall ties are in place and properly spaced. Check that the cavity is dry and free from water ingress. Ensure you have appropriate access and scaffolding for safe working at height. Wear suitable personal protective equipment including gloves and a dust mask when handling and cutting mineral wool. Store slabs in a dry location on site and protect from weather until installation. Follow the manufacturer's installation instructions and any specific requirements set out in your building control approval or design specification.