Bauwerk Colour Prep Coat is a white water-based paint that has three main functions:

1. It provides a completely uniform matte white background colour
2. It has the right amount of absorbency to allow the limewash paint to anchor itself into
3. Allows for an easy application with enough time to brush out the paint the way you prefer

Bauwerk Prep-Coat is not a sealer to block out stains or equalise absorbency differences. Prep Coat is an ultra-low VOC water-based base paint with a higher-than-usual amount of absorbing material content for use on interior surfaces.

Bauwerk Prep Coat is a ready-to-use product and only needs to be stirred thoroughly. It can be applied with a brush, roller or spray gun.

Natural walls, such as unpainted render, brick, stone, masonry, mud brick & limewash.
Do not require any undercoat or primer. Limewash can be applied directly to the wall.

Previously painted render, brick, stone, masonry, mud brick.
Carry out any surface repair and remove all dust and loose particles. Sand well if previous paint has any gloss level

1. Surface Preparation
Consult our surface guide to see if you require a primer-sealer coating prior to Prep Coat.
Where required, use our 3 x P Formula:

01 Prime: Apply 2 coats of a water-based undercoat-sealer/primer for even absorption*
02 Prep: Apply 1 coat of Bauwerk Prep Coat to act as a bridge between the primer and limewash paint
03 Paint: Apply 2 coats Bauwerk Limewash Paint

*If your walls are already correctly primed and have not been patched or repaired, you can skip this step.

Surfaces must be dry and free of dirt or separating substances.

2. Prep Coat Preparation

Stir well.

3. Application

• Prep Coat can be brushed rolled or sprayed.
• Start at the window and paint away from the light. If painting the ceiling—paint the ceiling first, followed by the walls.
• To avoid visible lines, or 'picture framing' effect that may appear once limewashed, always paint wet on wet, even when cutting in to keep the finish consistent and even.
• Blend your vertical strokes with horizontal strokes without loading any additional paint.
• Finish one wall in a single application.
  

In a lot of cases, you can limewash paint onto a clean light coloured unblemished surface that has no gloss level to it and skip the Prep Coat for the sample application.

However, if that is not the case, or you will need repaint the wall that you use for your samples, it is recommended to use the Prep-coat even for the samples. The Prep-Coat does intensify some colours, as it provides a nice pure white backdrop the pigmentation of the paint can get hold of.

Bauwerk Prep Coat is not a sealer. It will not hide any repairs or if you install additional drywall, it will not mask the absorbency differences between the drywall panel and the gap-filling material. For that, you need to apply a water-based drywall primer before you roll on the Prep Coat.

It’s not either actually. We specially developed Prep Coat as a bridging layer to enhance the durability and ease of application of limewash paint. Pure limewash paints require a moderately absorbing surface. However many interior spaces are already decorated with a conventional paint that does not allow the Limewash to penetrate.

Bauwerk Prep Coat creates a matte white uniform background and allows the Limewash paint to be applied easily and creates a more durable surface. 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.

No, Bauwerk Prep Coat was designed to improve conditions where they were less than ideal for limewash painting.

Apply Bauwerk Prep Coat…

• When your surface is indoor AND is non-absorbent. For instance, surfaces that have been previously covered with conventional paint or sealer can hinder the proper absorption of limewash. This layer of Prep Coat gives the limewash paint something to adhere to and creates a more durable finish.
• If your surface is made up of different substrates (materials). For example, a wall that has had repairs using different substances or a wall with brick on the bottom and drywall on the top. The limewash will absorb and present differently on these two materials. By using Bauwerk Prep Coat you will have an even neutral base to start from.
  
  

You do not need to use Bauwerk Prep Coat if…

• You’re limewashing an exterior surface
• Your limewashing an absorbent material with a consistent finish, For example, raw render, lime paster, unpainted bro or stone will naturally absorb limewash effectively.

Bauwerk Prep Coat is designed for internal use only.

For external surfaces, we would consider other materials. See our FAQ section for more information on surface preparation for external walls.

Bauwerk Prep Coat for limewash has a VOC content of less than 1gr per litre. The EU limit value for VOC content for this product is 30gr per litre. Many products in the US are classified as low VOC content with a VOC level of 300gr per litre.

By comparison from those values alone, our Prep Coat has a super-super low VOC content. Even so, during the painting process of Prep Coat almost all of the VOCs will be released. Simply airing the room will get rid of that. 

Furthermore, because our limewash paint has a very high ph-value any remaining VOC emissions will be eliminated. So you can be assured that after you finish painting you have used a painting system that is safe for a bedroom or a living room application from an air quality perspective.

Generally, our Prep Coat should be used within 6 months of the purchase date.

Bauwerk Prep coat should be stored in an airtight container, frost-free, away from direct sunlight, and out of reach from children.

Most surfaces can be painted with Prep Coat like previously painted surfaces, concrete, ceilings, drywall + gypsum plasterboard
gypsum + lime plasters, wallpaper, previously painted brick and masonry, ply and pine wood.

Prep Coat Coverage per litre

• Smooth wall substrate: 6 m2 ( 64 ft2 )
  
• Rough wall substrate: 5 m2 ( 54 ft2 )
  
  

Values for coverage are to be used as a guide only. Variation in the quantity needed will depend on the porosity of the surface to be painted.

The surface will be dry 2-4 hours after Prep Coat is applied. Allow longer at lower temperatures and higher humidity.
Do not use below 5°C (41°F)

Bauwerk Prep Coat is designed to be a one-coat application.