Graphenstone – GCS Exterior The Ultimate Lime Silicate Heritage Paint

Natural Lime Silicate Heritage paint, Breathable and Exterior Durable. High Coverage Rates low Applied Costs. Extensive Colour range in a Matt Finish. Perfect for Period homes, Cottages and restoration projects on lime rendered walls.

The colours depicted on the site are for guidance only. The displayed colour will depend on your monitor and browser. All products are manufactured on computer controlled tinting machines matched to the official colour standards. Once manufactured orders cannot be cancelled or refunded.

Graphenstone – GCS Exterior The Ultimate Lime Silicate Heritage Paint

GCS Exterior is a natural lime silicate breathable heritage paint for exterior and interior lime rendered walls with a durable 2% matt finish. Ideal for town houses, cottages, period homes and restoration projects. Based on lime silicate reinforced with graphene technology, it has excellent coverage (14m2/lt) and durability.  A breathable coating recommended for use on lime renders often found in period properties, reducing condensation. Exterior durable and Fire rated A2-s1,d0   it is the ultimate lime silicate heritage paint meeting high environmental standards, EPD Verified. Suitable on lime renders, plaster, modern plasters and previously painted surfaces. The economic alternative to Keim. Available in an extensive range of colours in 1lt, 4lt and 10lt recyclable containers for free delivery throughout the UK.

Environmental Credentials

  • Natural Lime Silicate Heritage paint, Exterior Durable. Breathable Class 1 Finish perfect for Period homes, Cottages and restoration projects on lime rendered walls.
  • High Environmental Standards. No Microplastics. Trace VOCs. Low GWP and Carbon Footprint. EPD Verified. Cradle to Cradle Silver, BREEAM, WELL & LEED. Global Green Tag Platinum.
  • Ultra Matt Exterior Durable Heritage Finish. Fire Rated A2-s1, d0. Excellent Coverage 14m2/lt. Economic alternative to Keim. Recommended on Lime Rendered Walls. Extensive choice of Heritage & NCS Colours. Free UK Delivery.

Technical Credentials

Excellent Coverage 14m2/lt per coat

Breathable Class 1, Sd <0.08

Wet Scrub Class 1 ISO 11998

Fire Rated A2-s1, d0

Alkaline pH 12

Volume Solids 52%

Overcoat 2-4hrs

Environmental Credentials

Cradle to Cradle Silver

LEED, WELL & BREEAM Accredited

Global Green Tag Platinum

EPD Verified

GWP 0.12 CO2e kg/m2 per coat

Low Carbon Footprint

No Microplastics. MIT Free

Ultra Low VOCs <1g/lt

Surface Preparation

Suitable for lime renders, lime plaster, gypsum, modern plasters, lime plasters, brickwork and previously painted surfaces. On new plaster apply a mist coat of Nevada Ultra to reduce costs.

Absorbent substrates such as concrete block and brick, it is recommended to prime with Ambient Primer . Ambient Pro primer can be thinned using 10-15% by volume with water to ease application.

For previously painted hard surfaces, ceramics or glazed tiles prime with Four2Four adhesion promoter.

Remove all loosely adhering material back to a sound edge, the surface must be dry and free of surface contamination.

Application may be by brush, roller or spray.

Apply two full coats of GCS Exterior. Allow 2-4 hours between coats. Full cure and properties will be achieved after 30 days.

Download the technical data sheet for more information.

Energy EfficientGCS Exterior  is a Lime Silicate Heritage paint which is Breathable  Class 1 rated with an SD value <0.08, reducing condensation. It is an ideal ecological sustainable heritage paint for interior and exterior walls on period properties, cottages and restoration projects. It can be applied to lime and modern renders and various types of masonry. It has an easy clean surface with a Class 1 Wet Scrub finish . It is fire certified not to spread surface flame meeting  BS476 Part 6 and 7 and  Fire Rated A2-s1, d0.

GCS Exterior is reinforced with graphene providing excellent durability, flexibility and adhesion it can be applied to most surfaces including lime rendered exterior walls, plaster, gypsum and brick.  It has excellent flexibility bridging hairline cracks on plastered surfaces, excellent adhesion to lime based renders, good colour and gloss retention in an exterior environment. It is perfect for use on period buildings, restoration projects, cottages, town houses and country homes.

GCS Exterior is a high solids (52%) water based paint easy to apply by brush or roller with high coverage rates 14m2/lt , twice the coverage rates of other lime silicate paints. Available in a bespoke range of 96  heritage and 226 NCS colours in an ultra matt 2% finish. Use Nevada Ultra as a primer mist coat on exterior & interior walls or Ambient Pro Primer on porous surfaces. Packed in 1lt, 4lt and 10lt recyclable containers with free UK delivery. Sample Pots (100ml) also available for selecting your preferred colour schemes.

Traditional building materials like lime and clay have been used to decorate and protect buildings inside and out for thousands of years. In the past this meant using a limewash or other more delicate materials such as distempers. These coatings, whilst allowing the substrate to breathe effectively, were often more difficult to apply consistantly , lacked durability and offered  a limited lifespan. Modern plastic based paints cannot be used as they do not allow the lime wall to breathe resulting in damp, mould and detachment. Clay paints have low coverage rates increasing the applied costs per metre and have not been verified with an EPD rating.
GCS Exterior is an ecological sustainable natural paint based on lime silicate blends enhanced with Graphene for extreme durability. It is an exterior durable coating with 20 Years colour and protection performance. Ideal for application on lime based renders and constructions often found in period properties.
It has a low Carbon Footprint verified by Environmental Product Declaration (EPD) with a Global Warming Potential  (GWP) of 0.012 kg/m2 CO2e per coat. A Carbon footprint 85% lower than Keim and significantly lower applied costs. A building project of 1000 sq metres, requiring two coats  could result in a carbon saving of 950kg of CO2.

As we strive to reduce embedded carbon in our buildings, it is important to check the GWP rating of the materials used, independently verified by EPD. Some materials claim to be compliant coatings yet have no EPD data.


Asthma FriendlyGCS Exterior has been certified Cradle to Cradle Silver. It contains No Microplastics which is a major source of pollution in our rivers and oceans. With only Trace VOCs (<0.1g/lt)  it meets high environmental standards, Global Green Tag Platinum and certified by LEED, BREEAM and WELL building standards. Available in a unique range of heritage colours and 226 NCS colours in an ultra matt 2% finish, ideal for restoration projects, historic period buildings, town houses, cottages and country properties.

We are committed to the environment using only natural raw materials. Awarded Cradle to Cradle Silver Certificate, representing rigorous achievement across five critical categories: material health, material recycling, renewable energy and carbon management, water stewardship and social fairness, requiring continual improvement. The material health category uncovers every single chemical component and tests to 100ppm to ensure products are made using materials that are safe for humans and the environment. Products with a whole green life cycle complying with Reuse, Reduce and Recycle philosophy, guaranteeing the most efficient use of materials.

Order GCS Exterior online for free next day delivery throughout the UK. Alternatively for pallet quantities please email with your product requirements, quantities and delivery address, our customer service team will respond with our quotation.

Please note sample pots are based on GrafClean and are for colour selection only, they will not exhibit the properties above. For all orders of 4 or more Sample pots (100ml) the delivery is free and will include a free Graphenstone Colour card. Orders for only one sample pot will carry a small order carriage charge.

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