Leatherstone Polished Plaster

Proprietary multicoat plaster system with a seamless finish combining lightly polished stone with distinctive pitting and surface movement. It is crafted from natural materials including hydrated lime and crushed marble.

Features and benefits:

• Self-finishing, with non-directional open texture and partial honed surface.

• Lightly polished stone with distinctive pitting and surface movement finish. Choice of applied colours available.

• British fire test result: Class 0 (as defined in paragraph a12(B) of Building Regulations (E&W) Approved Document B).

• Surface spread of flame (to BS 476-7): Class 1.

• System is water vapour permeable and is suitable as a finish for traditional plastered masonry, including historic buildings.

• Pencil hardness (to ASTM D 3363): 5H+, surface hardness increases with age and carbonation of the material.

• Impact resistance (to ASTM D 2794): Two inch pounds.

• Shore D hardness (using Elcometer 3120 Shore Durometer D): 60.

• Wet scrub resistance (to ASTM D 2486): Exceeding 10 000 cycles.

• Spread of flame (to ASTM E 84 - 98): Class 1.

• Compressive strength: 28 N/mm².

• Mould and mildew resistance (to ASTM D 3273 and ASTM D 3274): Resistant.

• VOC Content (to ASTM D3960): 0 g/L.

System:

- Substrate:

• Generally suitable for application to plastered or rendered masonry such as block, brick or concrete and to taped and skimmed boards such as Bluclad, plasterboard, glassfibre reinforced gypsum (GRG), primed medium density fibreboard (MDF) and with care on previously decorated (but not papered) surfaces. Consult manufacturer.

• Surface to be true, flat and even, free of curing compounds, dust and other impurities, such as oil, grease and salts.

• Substrate to be prepared by others. General information is available for selection or preparation of suitable materials. Detailed consultation with supplier is also recommended to ensure best results.

• Plaster beads to be installed by others. Prior consultation with supplier is recommended to ensure appropriate detailing.

• Will not obscure cracked or uneven substrates.

- Materials and number of coats:

• Selection of materials and number of coats determined by supplier to achieve required finish.

• Where surfaces are of uneven suction: One coat Armourcoat K40 Primer by brush or roller.

• Where surfaces are not uniformly flat or smooth: Two coats Armourcoat K124 or K149 Keycoat (each typically 0.5 mm) applied by trowel over primer.

• On unsealed plasterboard or gypsum plaster: one coat Armourcoat Anti Crack Skim Coat Plaster (typically 3–5 mm) applied by trowel. Can be combined with reinforcement mesh. Taped and filled joints not required. Top layer of plasterboard to be left by main contractor with 3–4 mm open joints prior to application of Armourcoat Anti Crack Skim Coat.

• Topcoat: Two/three coats Pitted finish (total approximately 2–2.5 mm).

• Partly self-polishing when trowelled.

• Allow plaster to dry for at least 24 hours under good drying conditions before application of colourwash.

• Colourwash to be applied by sponge float, acrylic decorators' sponge or a lint free cotton cloth. Consult manufacturer for information.

Programme:

• Time required on site varies with finish criteria and work conditions.

• Number of coats may vary with desired finish.

• Application time may vary with desired finish, as well as accessibility of the working area.

• Drying time for each coat varies with temperature, humidity, suction and airflow.

• Adjacent finishes may need to be protected during application, particularly during sanding of dark colours.

• May need to be protected during completion of adjacent building works.

Control joints:

• Joints are advised between each day's work. Maximum daywork area is determined by number of staff working together, accessibility, environmental conditions and finish required. Consult supplier.

• In addition to work joints, need for expansion joints may be determined by the structural engineer. Detailing to be agreed with supplier.

• Consistency of finish requires consistency of application. Special consideration is necessary for areas of constrained access.

Application:

Suitable for application to a range of substrates. For internal use (external use possible in sheltered locations in limited colour range). Not suitable for application to substrates with high water content.