Plaster Surface Guide

Plaster walls are generally a smooth plaster finish applied to internal walls that dries hard. Plaster is also used for internal wall or ceiling mouldings. Depending on the region, plaster can be composed of set lime, as in Western Australia, or pink gypsum skim coat plaster, as commonly found in the UK.

There are also clay plasters and heritage lime plasters. If breathability is a concern, these types of plaster may have different considerations in their preparation methods. See above for more information.

Yes, Bauwerk Limewash is suitable for all types of plaster walls. View limewash application instructions for all types of plaster in our step-by-step guide at the top of this page.

To be sure of your colour, we always recommend testing using a Sample Pot of limewash.

If you are painting a plaster wall that's either already painted* or that you need to prime and prep, see the above step-by-step guide for preparation instructions. Then you can apply your limewash paint directly onto the primed and prep-coated wall. Once you have chosen your colour, apply another coat of Prep Coat over your samples, and then you're ready to start limewashing.

Another method that may be easier is to apply your samples onto a board that has been coated with Prep Coat. This enables you to carry the samples around the space and assess them in different lighting conditions, while also avoiding show-through of sample areas on your final finish. Use this method if you are painting naturally breathable walls like lime plaster, render or unpainted brick.


*If your plaster wall is previously painted with conventional paint, you will need to apply a coat of Bauwerk Prep Coat before applying the Limewash. This means that you are able to sample on the wall, as any sample patches will be covered with Prep Coat and will not show through on your final finish. 

It is very important that your raw plaster walls are correctly primed, as Limewash and Prep Coat won't mask, or seal over what is on your wall. For example, inconsistent materials within the plaster may ghost through as patches in the final finish.

Newly plastered walls can be very absorbent, making it a little tricky to achieve a consistent appearance. To achieve a uniform finish on raw plaster, we recommend sealing the surface. This ensures a consistent appearance, prevents the ghosting of micro-cracks, and helps minimise absorbency.

Note: If your walls are historic lime plaster or clay plaster and need to remain breathable, we don't recommend priming them. See above for alternative techniques.

Limewash applied directly to raw plaster, such as lime or clay plasters: 7-10m² (75–107 ft²) per litre, per coat (2 coats required)

Limewash over Bauwerk Prep Coat: 10–15 m² (107–161 ft²) per litre, per coat (2 coats required)

Bauwerk Prep Coat over Previously Painted/ Sealed walls: 6 m² (65 ft²) per litre, per coat (Only 1 coat required)

Note: Recommendations for coverage are to be used as a guide only; variation in quantity needed will depend on the porosity of the surface to be painted. We always recommend the use of Sample Pots for an accurate colour representation and consumption for your particular surface and light conditions. 

Step 1 : We recommend 2 coats of a water-based undercoat-sealer/primer –not a mist coat and non-diluted.*
Step 2: Apply 1 coat of Bauwerk Prep Coat. **
Step 3 Apply 2 coats of Bauwerk Limewash Paint.

* You can skip Step 1, if your walls are already correctly primed and without patches and repairs. If your walls are historic lime or clay plaster and need to remain breathable, we don't recommend priming, see considerations above.

**Do I need Bauwerk Prep Coat? We have specially developed our Prep Coat as a bridging layer to enhance the durability and ease of application of limewash. Bauwerk Prep Coat is not a primer; it’s a preparatory paint recommended for non-porous indoor surfaces to create the ideal conditions for applying limewash paint. Important: Bauwerk Limewash and Prep Coat have no capacity to mask what is on your wall.

View detailed instructions in our step-by-step guide above.

Yes, you can limewash a plaster wall that has already been painted with conventional paint, however the preparation is important.

Step 1 : If your previously painted walls have been patched/repaired you will need to apply 2 coats of a water-based undercoat-sealer/primer over these areas, to ensure a consistently sealed surface. *
Step 2: Apply 1 coat of Bauwerk Prep Coat. **
Step 3 Apply 2 coats of Bauwerk Limewash Paint.

* You can skip Step 1, if your walls are already correctly primed and without patches and repairs.

**Do I need Bauwerk Prep Coat? We have specially developed our Prep Coat as a bridging layer to enhance the durability and ease of application of limewash. Bauwerk Prep Coat is not a primer; it’s a preparatory paint recommended for non-porous indoor surfaces to create the ideal conditions for applying limewash paint. Important: Bauwerk Limewash and Prep Coat have no capacity to mask what is on your wall.

View detailed instructions in our step-by-step guide above.

• Apply 2 coats of Bauwerk Limewash using a Bauwerk natural fibre brush. Dip the brush into the bucket and flick off excess paint. The brush can hold a lot of paint, but should not be dripping. 
• Using loose, free strokes, stretch the paint as far as possible in all directions. Maintain a wet edge at all times to prevent colour overlays. Do not leave drips or runs. Continue to stir paint regularly while painting.
• Allow 1–2 hours between coats. When wet, the colour will appear darker and transparent. As the paint dries the colour will lighten and become opaque. 
• During construction or renovation, it is advisable to schedule Bauwerk painting as the final trade to prevent damage to the final finish caused by other trades or building equipment.
  
  
  View detailed instructions on limewash preparation and application in our step-by-step guide provided above.

High-quality, natural limewash needs adequate curing time. This will be longer in colder weather and in humid conditions. The ideal temperature for applying Bauwerk Limewash is 8°–30°C (46°F–86°F). Do not paint if the surface and/or air temperature falls below 5°C (41°F) during application or curing. 

Not at all—you can limewash your ceiling at any time. Just be mindful not to splash or overpaint the surrounding walls while doing so.

A great tip? Consider hiring a mobile scaffold to make the job easier.