EWI-745 Insulating Cork Render is a lime-based thermal insulation mortar that combines the natural breathability of lime with the insulating performance of cork. Designed for both internal and external use, it provides a lightweight, vapour-permeable render that helps regulate moisture while improving thermal efficiency.
Its cork content delivers insulation without compromising adhesion or workability, making it particularly suitable for projects where breathable construction and improved thermal performance are required. Spray-machine compatibility also allows EWI-745 to be applied efficiently across large areas and complex architectural shapes, making it a versatile solution for both heritage and modern construction.
Intended Uses
EWI-745 Insulating Cork Render is suitable for internal and external applications on a wide range of mineral substrates, including:
- Brick and masonry
- Thermo-clay blocks
- Concrete blocks
- Lime-based mortars
It is suitable for use on both vertical and horizontal elements. Use on OSB panels is not recommended. Where insulation thicknesses greater than 80 mm are required, rigid insulation systems should be considered.
Key Benefits
- Combines breathable lime with natural cork insulation
- Improves thermal performance while maintaining vapour permeability
- Lightweight and easy to apply
- Helps regulate moisture and reduce condensation risk
- Highly breathable, supporting healthy building fabric
- Suitable for spray or hand application
- Adapts well to curved and irregular surfaces
- Durable, traditional lime appearance
- Suitable for both heritage and modern construction
Compatible Products
EWI-745 Lime & Cork Insulating Render must be finished with a compatible breathable lime coat and protected with vapour-permeable finishes to ensure correct curing and long-term performance.
EWI-748 Lime Basecoat NHL 5
EWI-748 can be applied over cured EWI-745 to provide a stronger, reinforced lime surface prior to decoration. The basecoat must be reinforced with alkali-resistant fibreglass mesh where specified.
EWI-749 Fine Finish Lime Plaster
For projects requiring a finer decorative lime finish, EWI-749 may be applied directly over properly cured and prepared EWI-745.
EWI-707 Lime Wash
Lime Wash provides breathable surface protection once the finishing coat has cured, supporting carbonation while maintaining vapour permeability.
EWI-705 Lime Paint
Once fully cured, Lime Paint can be applied to enhance colour consistency and durability while allowing the system to continue managing moisture naturally.
Lime Wash can be blended with Lime Paint to create bespoke, heritage-style finishes, offering additional creative control while maintaining full breathability and surface protection.
Substrate Preparation
Substrates must be solid, clean and dry, free from previous plasters, gypsum, cement residues, biological growth or any materials that could impair adhesion.
Before application, dampen the substrate with clean water, ensuring it is moist but not saturated. This promotes good adhesion, correct curing and helps prevent rapid dehydration and cracking.
For older or uneven substrates, a levelling parge coat is recommended to achieve a uniform background prior to application.
Product Preparation
EWI-745 is supplied as a 10 kg dry powder.
- Mix each bag with 4.5 litres of clean water
- Mix for 3-5 minutes until a homogeneous consistency is achieved
- For larger volumes, use an electric mixer at low speed
Once mixed, the mortar has a working time of approximately 60 minutes.
Application
EWI-745 can be applied by spray machine or trowel, depending on the application and required build-up.
Spray application:
- Apply in layers of 1-3 cm thickness
- For thicknesses greater than 3 cm, apply in multiple layers before the previous layer hardens
Trowel application:
- Apply in layers with a maximum thickness of 1-1.5 cm
- For thicknesses greater than 1.5 cm, apply in two or more layers before the previous layer hardens
Ensure even coverage across the entire surface.
Technical Data
|
Property
|
Value
|
|
Product Type
|
Lime & Cork Insulating Render
|
|
Appearance
|
Dry powder
|
|
Finish
|
Off-white (light beige)
|
|
Coverage
|
Approx. 2.6 kg/m² per cm
|
|
Thermal Conductivity
|
≤ 0.055 W/mK
|
|
Apparent Density (Hardened)
|
467 kg/m³
|
|
Adhesion to Substrate
|
≥ 0.2 N/mm²
|
|
Compressive Strength
|
CS I ≥ 1.2 N/mm² (28 days)
|
|
Water Vapour Permeability
|
μ ≤ 3.6
|
|
Water Absorption
|
≥ 0.07 kg/(m²·min⁰·⁵)
|
|
Working Time
|
Approx. 60 minutes
|
|
Minimum Thickness
|
10 mm
|
|
Maximum Thickness per Layer
|
80 mm
|
|
Packaging
|
10 kg bag
|
|
Shelf Life
|
Up to 12 months
|
Storage Conditions
Store in original, unopened packaging in a cool, dry location, protected from rain and moisture. Once opened, it is recommended that the entire bag be used. Shelf life is up to 12 months from the date of manufacture.
