Casein Bound Limewash
A traditional natural permeable paint for the decoration of lime plaster, lime render, limestone, soft brick and porous building materials. Casein, a natural glue, is added to improve adhesion and ‘rain-shedding’ properties when used externally. Limewashes do not ‘dry’ like modern paints but ‘set’ by reaction with atmospheric carbon dioxide in the presence of moisture. For Interior and Exterior use.
Additional information
Casein Limewash is an exterior grade limewash but is also often used internally due to its superior adhesion properties and as it is less likely to brush off on clothes than Pure Limewash. Casein Limewash should be applied to damp surfaces: lime plaster and render, porous stone and brick must be thoroughly moistened with a mist spray prior to application. Casein limewash should be protected from drying too quickly, and from rain, wind and frost before carbonation. See our technical advice here.
Environmental Considerations
Limewashes are made with natural sustainable ingredients. They contain no VOCs, no petrochemical based ingredients, and no lead. Water-based. All Rose of Jericho paints comply with the latest environmental legislation. This product contains both a fungicide and an algaecide.
Usage/Purpose
Casein Limewash is an exterior grade limewash but is also often used internally due to its superior adhesion properties and as it is less likely to brush off on clothes than Pure Limewash. It can be used on less porous surfaces including hydraulic lime based plasters and renders, although sample trials should always be carried out to assess compatibility with substrate. Casein limewash is more compatible with ‘open-textured’ wood or sponge floated plaster and render surfaces than tight smooth steel-trowel polished surfaces.
Coverage
Approx. 6m2/litre/coat depending on texture and porosity of surface.
Shelf Life
At least 3 months shelf life when kept cool in sealed containers. Casein limewash must be stored in a cool frost-free environment, away from heat and direct sunlight. Tins and tubs must not be kept in the van in sunny weather and must be moved to a cool/cold environment. Protect from heat and frost.
Finish
Matt surface coating. Colours are darker in tone when wet.
Colour
Casein limewash is not available in plain ‘White’. Colour matching service available. Coloured limewash is made using natural powder pigments. Variations due to these pigments and differing porosity of surfaces are inevitable. Much of the charm of a traditional finish is its lack of uniformity with subtle variations of colour and tone.
Observations
Casein limewash cannot be used on previously painted surfaces unless the existing paint is limewash. Casein limewash should be protected from drying too quickly, and from rain, wind and frost before carbonation. Casein limewash is not suitable for use on 'sky-facing' surfaces or weathering details and is not to be used in unprotected exposed locations.
Preparation
Casein Limewash requires a surface that is firm, clean, and porous. It can be applied to new lime plaster and render before it has fully dried and carbonated as the permeable nature of a limewash permits carbonation of the plaster beneath to continue. Casein Limewash can be applied to previously limewash painted surfaces, although sample trials should be undertaken. Previously limewashed surfaces should be thoroughly brushed and washed with a wet sponge to remove dust, dirt and all loose chalky material that is removed readily. Any algae or mould must be treated with an algaecide or fungicide and thoroughly washed off with clean water. Do not use proprietary fungicides containing water repellents. Make good and fill with a compatible material. Casein Limewash should be applied to damp surfaces: lime plaster and render, porous stone and brick must be thoroughly moistened with a mist spray prior to application.
Application
Ensure limewash is within shelf-life period. Casein Limewash must be thoroughly mixed, preferably with a mechanical whisk, to ensure even distribution of pigments and ingredients immediately before and during use as it readily settles out. Protective clothing and goggles must be worn and great care taken especially when limewashing ceilings. Surfaces must be damp. Porous pre-wetted surfaces may need additional mist-spraying during application to ensure that the limewash does not dry too quickly. Casein limewash must not be applied to sunlit surfaces, and application must be delayed until the wall is in the shade. Apply the limewash to the damp surface using a brush, not a roller, working it into any cracks. It is applied in thin coats - limewash appears transparent on application and care must be taken to avoid thick build-up that will craze on drying out and may obscure detail. Normally, 3 coats are required, occasionally more. Each coat must be protected from drying too quickly by regular mist-spraying, and a reasonable time (at least 24 hours, often longer) allowed between coats. It is normal to mist-spray the previous coat prior to the application of the next coat. Newly applied exterior Limewash must be fully protected from rain, wind, direct sunlight, frost etc until it has cured and carbonated (normally about 4 weeks)
