Natural Clay Plaster

The Gypsum Alternative

Description

• Natural clay plaster is a natural material which is created by composing rocks and minerals, mixed with sand and water to create a workable material for plastering.
• A more environmentally friendly choice than traditional gypsum plaster.
• The surface finish is typically matt, although some polished surface finishes can be created.
• Smooth or rough textures can be created when drying.

Uses

• Clay can be used as a plaster undercoat, medium finish and fine finish.
• Available as a general plaster that needs painting.
• Available as a pre-coloured plaster which does not need painting.
• A primer may be required when using on some surfaces.
• Suitable for both historic and modern interiors.
• Can be used in moist areas, unless in direct contact with water.

Advantages

• A 100% natural, breathable material which absorbs moisture.
• Material naturally absorbs odours.
• Natural properties are anti allergic.
• Plaster can be used with a range of absorbent backing surfaces; brickwork, board, gypsum, plasterboard and plaster undercoat.
• Excellent noise insulation properties.
• Natural fire resistant qualities.
• A good regulator of temperature (keeping warm in winter and cool in summer) and humidity levels.
• Can be left unfinished without surface paint.
• A non dusting finish.
• Plaster finish is easily maintained by soaking area with water and refilled.
• Can be treated the same as gypsum plaster using the same paint, fixtures and fittings.
• Plastering with clay is a quicker method than with traditional gypsum plastering.
• Long drying time means that it is workable for longer.

Disadvantages

• Water will penetrate the finish with direct contact and swell as it absorbs water.
• Constant flow of water will erode a clay finish e.g. drips.
• The drying time can take up to one week.

Embodied Energy

• Transportation will increase levels of embodied energy.
• Lower level of embodied energy during manufacture as material is not fired in a kiln at high temperatures as other clay products.

Source/Origin

• Readily available in most regions.

Renewable

• Sources of clay are not renewable, however they are abundant.

Environment and Health

• Extraction of raw material and quarrying can destroy natural habitats and landscapes.
• Water based sealants can be found to seal plaster.
• Natural clay plaster will only retain its breathable qualities if sealants and paints are non synthetic.
• No VOC emissions.

Performance

A durable and stable plaster, some types are comparable with concrete.

Recycled content

• n/a

Recyclable

• n/a

Disposal / Biodegradable

• Yes

To read more on plaster visit my article on Lime Plaster.