EXTERNAL WALL INSULATION IN LONDON
Essex, Kent, Surrey, Woking, Cambridge & surrounding areas.
What is EWI (External Wall Insulation)?
External wall insulation (EWI) is an advanced system that significantly improves a building’s energy efficiency and comfort by forming a continuous thermal envelope around the structure. Rigid insulation boards are securely fixed to the exterior masonry and overlaid with a breathable silicone render. Together these layers create a seamless barrier that reduces conductive heat loss and eliminates cold spots that typically form at external walls and junctions.
A Warmer, Greener Home With External Wall Insulation
Key Properties & Benefits of EWI
Space saving: EWI is applied entirely to the exterior of the property which means you retain one hundred percent of your internal floor space. This eliminates the disruption of moving radiators or electrical sockets and avoids the need for internal redecoration.
Energy efficient: The system creates a continuous thermal envelope around the structure which significantly reduces heat loss. By wrapping the building exterior, EWI stabilises internal temperatures and reduces energy consumption throughout the year.
Advanced moisture control: By moving the dew point to the outside of the masonry, the system prevents condensation and dampness from forming on internal walls. This contributes to a healthier living environment and protects the structural fabric of the building.
Acoustic insulation: The combination of dense insulation boards and reinforced render layers provides a significant reduction in external noise. This creates a much quieter internal environment which is ideal for properties located near busy roads.
Weather resistant: The breathable silicone top coat acts as a protective shield against driving rain and frost. This advanced layer allows moisture to escape from the inside while preventing water penetration from the outside.
At JVG London, we are fully qualified and highly skilled insulation specialists, delivering a quick and precise installations that ensure a flawless, weather-tight thermal barrier.
We install our advanced systems by securely fixing high-density insulation boards to the exterior masonry, creating a continuous envelope that keeps your home warm and dry.
Our team then embeds a reinforced fibreglass mesh into the base coat to provide an essential flexible foundation, ensuring the system remains resistant to cracks and structural movement. Finally, we apply a vibrant silicone topcoat with expert floating techniques, achieving a clean, modern aesthetic that eliminates the need for any future painting while significantly lowering your energy consumption.
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We use the full Licata EWI system, which includes:
Licata insulation boards (EPS or Mineral Wool depending on the property)
Licata adhesive and base coats for secure bonding
Fibreglass reinforcing mesh for strength and crack resistance
Mechanical fixings for additional stability
Licata silicone render for a clean, flexible, weatherproof finish
All materials are fully certified for the UK climate, breathable and designed for long term durability.
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Licata Silicone Render Colours (Grain sizes: 1.0 mm, 1.2 mm, 1.5 mm)
Whites & Lights
Chalk, Starlight, Gardenia, Cotton, Feather, Bone, Mist, Frost, Cloud, Whisper, Vanilla, Champagne, Rice Paper, Linen, Lace, CosmicWarm Neutrals
Silk, Buttermilk, Marigold, SandGreys
Pearl Stone, Silver, Clay, Ash, Smoke, Titanium, AnthraciteGreens
Olive, EucalyptusPinks & Reds
Pink Lemonade, Salmon, Oak, Earth
Our Process
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![A man working on home improvement, measuring a door frame on a brick house with painter's tape, while standing on a protective blue tarp with tools and supplies around him.]()
Preparation & Masking
Before any material is mixed, the property must be protected. We mask off windows, doors, and pathways. If there is existing render, we check for "blown" areas; these are hacked off and repaired to ensure a solid foundation.
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![A construction worker installing siding on the foundation of a residential building.]()
Base Profile Installation
A specialised, continuous starter track is precisely installed horizontally along the foundation. This profile is mechanically anchored through the damp-proof course (DPC), ensuring it is perfectly true and level to create a robust, airtight foundation that prevents cold bridging and fire spread.
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![A construction worker installing a new window on the exterior of a house. The worker is kneeling on the ground, holding a window frame, with tools and materials scattered around.]()
Graphite EPS Board Installation
Once the foundation is secure, high-density, grey (Graphite) EPS insulation boards are adhesive-fixed, seating the bottom row perfectly within the continuous metal starter track. These boards create a seamless thermal wrapper across the entire property, ensuring all raw substrate is covered to prevent thermal movement and energy loss.
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![A construction worker installing insulation or siding on the exterior wall of a house during a renovation or construction project.]()
Base Coat
The first layer of the system is the application of a high-polymer base coat. This specialised resin-based mortar is applied directly to the insulation boards to create a powerful, waterproof bond. This layer serves as the structural foundation for the entire render system, evening out the surface of the building and providing the primary defence against water penetration.
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![A man working on house exterior insulation or siding, with construction materials and tools around him.]()
Mesh Reinforcement
While the base coat is still wet, we embed an alkali-resistant fibreglass mesh into the entire surface area. This mesh acts like "armour" for your home, providing the tensile strength needed to absorb the natural movement of the building. This is the secret to a crack-free finish, as the mesh prevents structural shifts from ever reaching the decorative surface.
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![A construction worker reviewing plans outside a residential building.]()
Smoothing & Leveling
A second pass of base coat is applied to fully encapsulate the mesh, ensuring no fibres are left exposed. The surface is then professionally flattened and "sponged" to create a perfectly level, smooth substrate. This stage is vital because the final silicone top coat is very thin, so the walls must be perfectly true at this point to achieve a flawless finish.
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![A person painting the exterior wall of a house using a roller brush, standing on a plastic sheet with paint buckets nearby.]()
Priming
Once the base coat has fully cured—usually 24 to 48 hours depending on the weather—we apply a colour-matched primer. This layer seals the base coat to control suction, ensuring the top coat doesn't dry too quickly or unevenly. It also acts as a colour foundation, ensuring the final silicone render appears deep, vibrant, and consistent across every elevation.
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![A man working on painting or decorating the exterior of a yellow house with blue windows, using a roller brush. There's a pile of white bags, a paint bucket, and painting tools nearby on the ground.]()
Top Coat
The final layer is the silicone render itself, hand-applied to the thickness of the grain (typically 1.5mm). Our experts then "rub up" the render using a plastic float in a specific circular motion. This technique brings the aggregate to the surface, creating the uniform, modern, and hydrophobic texture that silicone render is famous for.
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![A man cleaning the exterior wall of a house with a broom outside on a sunny day.]()
Curing & Clean Up
Silicone render is air-drying and becomes shower-proof within just a few hours. Within 24 to 72 hours, the system is fully cured and at maximum strength. We then remove all masking tape and protective films, clean the site thoroughly, and leave your property looking brand new with a finish built to last for decades.
Book a Free Home Visit for a Personalised Quote.
Our team is available to provide expert advice, transparent pricing, and prompt communication. Please send us a message, and we will respond within the same day.
