Portland Stone Sheltercoat
Permeable lime-based materials for conserving or treating porous building materials including limestone, soft brick, and calcareous sandstone. Sheltercoats are individually designed to match the colour of the material to be treated, and are sacrificial coatings with the primary function of protecting the masonry beneath.
Available in 5 and 15 litres.
Additional information
Permeable lime-based materials for conserving or treating porous building materials including limestone, soft brick, and calcareous sandstone. Sheltercoats are individually designed to match the colour of the material to be treated, and are sacrificial coatings with the primary function of protecting the masonry beneath. Properly applied to appropriate materials they prove durable in sheltered locations. They comprise lime putty and fine stone-dusts, and occasionally natural pigments. Lactic acid casein, a natural glue, is added to improve adhesion and durability. Internal and external use.
Environmental Considerations
Sheltercoats 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
Sheltercoats are specialist materials intended for use by conservators or tradesmen with experience of the conservation of masonry. They are used primarily as a surface treatment to soft, friable or laminating porous limestone. They can also be used as a ‘surface finish’ to unify or homogenise the appearance of masonry, especially after lime-based mortar repairs have been carried out.
Coverage
Dependent on porosity and texture of surface to be treated (approx 2 to 3m2/litre/coat).
Shelf Life
At least 3 months shelf life when kept cool in sealed containers. Protect from heat and frost. Casein sheltercoat 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 environment.
Finish
Matt surface coating. Sheltercoats are darker in tone when wet.
Colour
Individually made to match the colour of the material to be conserved or treated.
Observations
Do not apply in temperatures of 50C or below, or if there is a risk of frost. Sheltercoats cannot be applied to painted surfaces. Sheltercoats must be protected from drying too quickly, and from rain, wind and frost before carbonation. Protection and regular mist spraying to prevent over rapid drying and to promote carbonation is necessary. Sheltercoats are not suitable for use on ‘sky-facing’ surfaces or weathering details and are not to be used in unprotected exposed locations. Sheltercoats carbonate and set by reacting with atmospheric carbon dioxide in the presence of moisture. Sheltercoating can be messy, and full protections must be provided to all vulnerable adjacent surfaces. In particular, any oak or oak flooring must be fully protected, as the alkali lime permanently stains hardwoods. Newly applied exterior sheltercoat must be fully protected from rain, wind, direct sunlight, frost etc until it has cured and carbonated (normally about 4 weeks).
Preparation
Any existing paint should be removed physically. If a chemical stripper is used, it must be properly neutralised as any residue of either stripper and/or neutraliser is likely to affect the performance of the sheltercoat. Sheltercoats require a surface that is clean and porous. Dusty, friable surfaces should be brushed free of loose particles. Heavily sulphated or salt-laden surfaces should be poulticed. Mould and algae must be treated with a fungicidal wash that includes an algaecide and does not contain a water repellent. Always moisten the surface thoroughly and again with a mist spray immediately before application.
Application
Ensure Sheltercoat is within shelf-life period. Thorough mixing preferably with electric whisk is necessary before and during application as the ingredients readily settle out. Experienced operatives familiar with the conservation of masonry should be employed. Application is determined by the condition and porosity of the material to be treated and the intended result. Sheltercoats are often applied in 2 or 3 coats, the first coat often diluted with clean water for very porous surfaces. Apply by brush, working in thoroughly. Second and third coats can be applied prior to the carbonation of previous coats. Dampen the surface with a mist spray between coats. Often, to avoid a completely homogenous finish, sheltercoats are wiped back from sound surfaces and ‘high spots’ whilst still damp leaving the material in the hollows and pores. Use a sponge, or soft paint brush and the minimum of water.
Availability
5 litre cans & 15 litre tubs. Sheltercoats are made to order and are normally supplied within 72 hours.
