Full Fill Cavity Boards

Full Fill Cavity Wall Insulation Boards & Batts

Full fill cavity wall insulation is engineered to completely occupy the cavity space between two masonry walls—eliminating air gaps and maximising thermal efficiency. This approach helps achieve low U-values, improve airtightness, and comply with Part L of the Building Regulations.

At Insulation UK, we offer a full range of full fill cavity boards and batts, including solutions in phenolic, PIR, mineral wool, and glass wool. Whether your priority is ultra-low thermal conductivity, non-combustibility, or ease of installation, we stock leading systems trusted across residential, commercial, and industrial builds.

Key Products in This Collection:

Kingspan Kooltherm K106

• Phenolic board with foil and fleece facings
• Outstanding thermal conductivity: 0.019 W/m·K
• Square-edged and ideal for masonry full-fill cavities

Recticel Eurowall Full Fill

• PIR board with rebated edges for tight joints
• Thermal conductivity: 0.022 W/m·K
• Suitable for new builds and extensions

Knauf DriTherm Cavity Slabs 32/37

• Non-combustible glass mineral wool batts
• Friction-fit design, Euroclass A1 fire rated
• Ideal for full-fill masonry cavity walls

Ideal For:

• Masonry cavity walls in new builds or extensions

• Projects requiring high thermal performance with minimal wall thickness

• Sites in exposure zones or areas prone to wind-driven rain

• Installations needing non-combustible or BBA-certified insulation

At Insulation UK, all full fill products are available in a wide range of thicknesses and are ready for fast UK-wide delivery. We stock only top-performing brands to ensure your project stays compliant and energy efficient.