Kingspan Kooltherm K118

What is Kingspan Kooltherm K118 insulated plasterboard?

K118 is Kingspan's insulated plasterboard, a fibre free, rigid thermoset phenolic insulation core bonded directly to 12.5mm plasterboard on the front face, with a composite foil facing on the reverse. Because the insulation and the plasterboard arrive as one board, K118 is fixed straight to the wall in a single step, rather than fitting insulation first and boarding over it separately afterwards. It is designed for internal use, upgrading the thermal performance of solid walls, cavity walls and framed walls from the inside.

Why choose insulated plasterboard for internal walls?

Two jobs, one board: Insulation and plasterboard are bonded together, so you save a fixing stage compared with boarding over separate insulation.

• Premium phenolic performance: Kooltherm's phenolic core is one of the lowest lambda insulation materials available, so you can hit a target U value from a thinner board than PIR insulation or mineral wool would typically need.
• Keeps more of your room: A thinner board for the same performance means less floor and wall space lost, which matters in smaller rooms or period properties with box bay windows and skirtings to work around.
• Ready to finish: The plasterboard face is ready for skim plastering or direct decoration once jointed, so there is no separate lining board to source or fit.
• A trusted, familiar brand: Kingspan is one of the best known names in UK insulation, so you are specifying a board with a long track record on residential projects.

How is K118 fixed and finished?

K118 Insulated Plasterboard is suitable for two fixing methods, depending on the wall:

Mechanically fixed: Screwed through timber battens or a metal furring system, a good option on uneven walls or where a small additional service void is useful.

Plaster dab or adhesive bonded: Bonded directly to a reasonably flat masonry wall using dabs of dry wall adhesive, a faster fit on straight, sound walls without the need for a batten framework.

Boards are cut and fitted in the same way as standard plasterboard, then jointed and finished ready for skimming or decoration. If you’re deciding between a full skim finish or simply taping and filling the joints, our guide on plastering versus jointing and filling walks through which is right for your project.

For larger jobs or awkward reveals, boards can also be cut to size through our bespoke cutting service.

Kingspan Kooltherm thicknesses and sizes available

We stock Kingspan Kooltherm K118 Insulated Plasterboard as 2.4m x 1.2m boards, supplied per pallet, in the following thicknesses.

• 37.5mm
• 42.5mm
• 52.5mm
• 62.5mm
• 72.5mm
• 82.5mm

Pallet pricing starts from around £998 ex VAT and varies by thickness and the number of boards per pallet. If your project also needs phenolic insulation underfoot, Kingspan Kooltherm K103 uses the same low lambda technology in a floorboard.

Why choose Insulation UK?

• The full Kingspan Kooltherm range. K118 Insulated Plasterboard available across the full thickness range for fast dispatch.
• Free delivery on orders over £500 ex VAT. Competitive pallet pricing across the range, with no minimum order on smaller quantities.
• Over 50 years of industry experience. A specialist team with detailed product knowledge across the full range of insulation materials and applications.
• Trusted by 20,000+ customers. From homeowners and self builders to national contractors, we supply to projects of every scale across the UK.

Expert help when you need it. Not sure which thickness or fixing method suits your wall? Get in touch and we'll point you in the right direction.