Graphenstone GCS Exterior Paint

Graphenstone GCS Exterior Paint is suited to restoring and redecorating heritage buildings, older properties and contemporary masonry façades. Choose it for projects where a traditional mineral appearance is required, particularly on buildings with lime-based construction.

For renovation work, check the condition and compatibility of existing coatings before painting. Use Graphenstone Ambient Primer L42 where the surface needs stabilising or its absorption needs regulating. GCS Interior provides an alternative for decorating rooms within the same property.

Suitability

Suitable for correctly prepared exterior mineral surfaces, including lime and cement render, brick, concrete and compatible mineral plasters. Existing paintwork must be firmly adhered and compatible with the chosen coating system. Complete a test area where suitability is uncertain. Not suitable for surfaces in permanent contact with water.

Explore these Graphenstone preparation products and alternative finishes for your project.

Product Use Graphenstone GrafClean Matt Paint Washable matt paint for interior walls and ceilings. Graphenstone GrafClean Eggshell Washable low-sheen finish for interior walls, ceilings and suitably primed woodwork. Graphenstone GCS Interior Paint Breathable flat matt paint for interior walls and ceilings. Graphenstone Ambient Pro+ Air Purifying Matt Paint Lime-based matt paint with light-activated air-purifying properties. Graphenstone Ambient Primer L42 Stabilising primer for absorbent surfaces before applying compatible paints. Graphenstone Siena Decorative limewash for interior walls and ceilings, with natural tonal variation.

Ensure all surfaces are sound, clean, dry and free from dust, dirt, grease and other contaminants before applying Graphenstone GCS Exterior Paint.

Take special care when removing or disturbing pre-1960s paint, as it may contain harmful levels of lead. Seek specialist advice if you are unsure.

• Remove loose, flaking or poorly adhered paint and any unstable masonry to provide a firm surface for the new coating
• Clean away dirt, grease, atmospheric deposits and other surface contamination, then allow the area to dry thoroughly
• Remove mould, algae and other organic growth with a suitable treatment, such as Sandtex Fungicidal Wash, following the manufacturer's instructions
• Brush away efflorescence and other loose surface salts using a stiff, non-metallic brush, then investigate and address the source of moisture
• Repair cracks, holes and damaged masonry with a suitable exterior filler, like Sandtex Ready Mixed Masonry Filler
• Resolve leaking gutters, defective pointing and other sources of persistent water ingress before decorating
• Allow new mineral surfaces, including fresh render and masonry repairs, to cure for at least 28 days before painting
• Apply Graphenstone Ambient Primer L42 to absorbent, powdery or unevenly porous mineral surfaces where required
• Use Graphenstone Filler where a compatible textured silicate primer is needed to even out surface texture or cover hairline cracks
• Mask and protect adjacent glass, metal, stonework and other surfaces that are not being painted

Always test the product on a small area before starting the project to confirm its suitability, adhesion and final appearance. Follow the manufacturer's instructions on the container at all times.

As this is a natural mineral paint, minor variations may occur between different containers or batches. If more than one container is required, mix them together before use to maintain a consistent colour across the surface.

• Apply when the air and surface temperature is between 7°C and 35°C and the relative humidity is below 80%
• Do not apply in direct sunlight, onto surfaces heated by the sun or when rain, frost or condensation is expected
• Shake the container and dilute the paint with 10-15% clean water
• Stir thoroughly before and during use, avoiding excessive mixing that could introduce air bubbles
• Apply 2 or 3 even coats by brush, roller or airless spray, maintaining a wet edge to reduce lap marks
• When using a roller, cut in and complete one wall at a time, rolling as close to the edges as possible to reduce picture framing
• Work the paint out evenly and avoid applying it too thickly, as excessive film thickness may extend drying times or cause micro-cracking
• For airless spraying, refer to the manufacturer's instructions and thin by approximately 15%
• Allow approximately 2-4 hours between coats under normal drying conditions
• Protect the freshly painted surface from rain, condensation and water for 4-5 days while the coating begins to cure
• Clean brushes, rollers and spray equipment with warm water immediately after use

Graphenstone GCS Exterior Paint takes approximately 30 days to fully cure. Avoid rubbing, washing or cleaning the surface during this period, and protect it from rain, condensation and direct contact with water for the first 4-5 days.

• Inspect painted surfaces periodically for dirt, organic growth, cracking or damage
• Remove light surface dirt using clean water, a soft brush or sponge and a mild, neutral cleaning solution where required
• Avoid abrasive cleaners, stiff wire brushes and high-pressure washing, as these may damage the mineral finish
• Remove mould, algae and other organic growth with a suitable exterior cleaner, following the manufacturer's instructions
• Repair cracks, defective pointing and sources of water ingress promptly to prevent moisture entering behind the coating
• Touch up damaged areas with the original paint after cleaning and preparing the surface

Store any remaining paint in its original container with the lid securely closed, in a cool, dry place between 5°C and 35°C. Protect it from frost, heat and direct sunlight.

What is Graphenstone GCS Exterior Paint used for?

It is used to decorate exterior masonry, lime render, walls and building façades with a breathable, low-sheen mineral finish. It is particularly suited to heritage buildings and traditionally constructed properties.

Which surfaces can Graphenstone GCS Exterior Paint be applied to?

It can be applied to compatible mineral surfaces, including lime and cement-based render, plaster, brick, stone and concrete. Surfaces must be sound, clean, dry and correctly prepared before painting.

Can it be applied over existing paint?

Yes, providing the existing coating is firmly adhered and compatible with the silicate paint, although a coat of Graphenstone Ambient Primer L42 is highly recommended. Remove loose or flaking material, lightly sand glossy areas and carry out a test application where compatibility is uncertain.

Does Graphenstone GCS Exterior Paint require a primer?

Graphenstone Ambient Primer L42 is recommended for absorbent, powdery or unevenly porous mineral surfaces. Wood, metal and non-porous surfaces require a suitable multi-surface primer such as Graphenstone Four2Four, although a test area should be completed before painting.

How many coats should be applied?

Apply 2 or 3 even coats, allowing approximately 2-4 hours between coats under suitable drying conditions. Avoid applying the paint too thickly, as this may extend drying times and cause micro-cracking.

Can Graphenstone GCS Exterior Paint be applied in all weather conditions?

No. Apply between 7°C and 35°C when relative humidity is below 80%. Avoid direct sunlight, heated surfaces and conditions where rain, frost or condensation is expected. Protect the finish from water for 4-5 days after application.

Why is this paint suitable for heritage buildings?

Its Class 1 vapour-open formulation allows moisture vapour to pass through the coating rather than trapping it within the wall. This makes it suitable for older and traditionally constructed buildings that require a breathable mineral paint system.