Pitted Polished Plaster

Proprietary multicoat plaster system, supplied and applied by Armourcoat Ltd.

Features and benefits:

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

• Wide choice of integral colours.

• British fire test result: CLASS 0 as defined in paragraph a12(B) of Approved Document B, ‘Fire Safety’, to the Building Regulations 1991.

• BS476: Part7: 1997 Class 1 surface spread of flame.

• 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 when tested using Elcometer 3120 Shore Durometer D: 60.

• Wet scrub resistance exceeding 10000 cycles to ASTM D 2486.

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

• Compressive strength - 28 N/mm².

• Mould and mildew resistant. Tested to ASTM D 3273 and ASTM D 3274.

• 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, GRG (glassfibre reinforced gypsum), primed 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

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

• Partly self-polishing when trowelled.

• Applied coating, for higher sheen or increased protection against soiling: White wax, or Black wax.

• Applied coating, for breathable water repellence, frost resistance, mould inhibition: Armourcoat Armoursil.

- Thickness:

• Finished thickness of 1.5-2 mm.

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. Internal use. (External use possible in sheltered locations in limited colour range). Not suitable for application to substrates with high water content.