Thin Internal Wall Insulation (TIWI)
Cork Plaster | Cork Spray
What is Internal Wall Insulation?
Internal wall insulation is a method of improving a building’s energy efficiency by adding an insulating layer to the inside of external walls. It helps keep heat in, reduces cold spots and condensation, and can cut down on noise and mould.
What is Thin Internal Wall Insulation?
Thin internal wall insulation, like TIWI CorkSpray’s internal cork insulation, uses a seamless 4–6mm natural cork coating applied directly to your walls - No bulky boards, no lost space.
Made from sustainable cork with zero VOCs, this breathable, carbon-negative layer shifts the dew point to help stop mould, locks in warmth, and creates a healthier, quieter living space.
Internal Wall Insulation
Save Space, Save Time, Save Hassle.
Choose Cork.
Keep Your Space: Our cork insulation doesn’t steal valuable room or require radiators and fittings to be moved, with its ultra thin depth.
Less Labour, Less Disruption: Our seamless spray or trowel application is quick and tidy, no demolition, landfill waste, or disruption.
Fast Installation: Most jobs are done in 1 - 3 days, so you get back to normal life sooner.
Smarter Investment: Save on hidden costs, no need hire an electrician or carpenter, to replace your fixtures and fittings, due it its ultra thin design.
Average estimated costs per property type
(Prices will vary on location, substrate condition and installer)
Terraced House
£2,000-£4,800.00
Semi-Detached House
£3,500-£7,200.00
Detached House
£5,000-£12,000.00
Average External Wall Area in a Bedroom
£400-£1,200
(Notes: These are rough averages; actual sizes vary by house age, design, and extensions. Victorian terraces may be smaller, while modern homes or larger detached properties can exceed these ranges. For more precise figures, a site survey or architectural plans are best.)
Energy Efficient
Our insulation effectively helps to prevents heat loss at just 4mm+ thick, eliminating cold ingress due its seamless application, ensuring consistent thermal comfort across your building.
Vapour permeable (breathable)
Vapour permeable natural material suitable for all solid wall, stone built or new build alike.
Low conductivity
It acts as a thermal corrector in thermal bridges, with a low conductivity of both heat and sound or vibrations. It has a good coefficient of thermal conductivity of 0,047- 0,076 W/mK.
Acoustic conditioner
Acoustic absorbent, minimises impact, exterior and air noises. Vibrations in the floors are reduced and new sound sources are eliminated in the receiving room.
Technical Specifications
Thickness: 4mm+
Fire Reaction
(UNE-EN 13501:2002):
Bs2d0 and Broof (t1)
Thermal Conductivity
(UNE-EN 12667:2002):
0.047–0.076 W/mK
Our cork-based insulating backing coat is applied before plastering, offering a strong, seamless, and ultra-thin internal wall insulation solution.
Performance Overview
Thermal Insulation
Reduces heat transfer and thermal bridging, maintaining indoor temperatures and lowers energy consumption.
Breathable
Protects from moisture infiltration, while allowing walls to breathe as needed.
Ecological
Made from natural, sustainable cork, non-toxic resins and pigments.
Get A Free Quote Today
Invest in a warmer, greener future with our thin internal wall insulation. Contact us now to learn more and transform your space with ease! Whether you're upgrading an existing property
or planning a new build, our cork insulation coating is the perfect choice for those who prioritise sustainability and efficiency.
