Limewash can turn an ordinary wall into a surface with depth and soft tonal shifts. Whether it works out, though, is decided before you even open the tin.
Limewash does not form a film on the wall like conventional paint. It soaks into the surface and leaves a thin layer of limestone behind, which is why it does not peel and the wall keeps breathing. To bond properly, though, it needs a moderately absorbent surface. And keep in mind: limewash hides nothing, whatever is on the wall beneath it will show in the result.
- The surface must be free of dust, dirt and loose material, and evenly absorbent everywhere.
- Raw render, brick and stone need no primer at all.
- Drywall, plaster and painted interior walls need 1 coat of Prep Coat. New, repaired or stained surfaces also need 2 coats of water-based primer first.
- A painted facade needs a coat of thin acrylic render.
- Paint at 8 to 30 °C, never below 5 °C. Outdoors, allow for three days without rain.
Find your surface
Before you pick up a brush, work out what is on your wall. That tells you which route to take.
Every route ends in the same place, the only difference is how many steps lie ahead.
| Your surface | Preparation | Prep Coat? |
|---|---|---|
| Raw render (interior and exterior) | Clean, dampen if dry | No |
| Exterior brick, stone | Clean | No |
| New or repaired plaster | 2× water-based primer | Yes, 1 coat |
| Drywall | 2× water-based primer | Yes, 1 coat |
| Painted wall, no repairs or stains | Sand gloss, matt needs no sanding | Yes, 1 coat |
| Painted wall with repairs or stains | 2× water-based primer | Yes, 1 coat |
| Interior concrete, ceilings, wallpaper, wood | Depending on condition | Yes, suitable |
| Painted facade | Repairs, sand gloss, thin acrylic render | No, interior only |
Why absorbency matters so much
Most painted surfaces are not absorbent enough on their own. For an even finish, the entire surface must absorb equally, including repaired areas and filled cracks.
If absorbency is uneven, drywall joints or repairs can ghost through the final coat. Neither limewash nor Prep Coat will mask them.
Use a good quality water-based drywall primer, never a solvent-based one. Whether it is tinted or clear does not matter, what counts is that it evens out absorbency. Apply 2 full, undiluted coats and follow the manufacturer's drying time between them. Any building merchant can recommend a suitable product.
Prep Coat: the bridge between your wall and limewash
Lime Wash Prep Coat by Bauwerk is not a primer or a sealer. It is a preparatory paint with a higher share of absorbent material that creates a uniform matt white base with the right absorbency. It does not even out stains or absorbency differences, which is why repaired walls need a primer underneath it.
| Property | Detail |
|---|---|
| Use | Interior only |
| Coats | 1 |
| Application | Brush, roller or spray |
| Coverage | Approx. 6 m² per litre |
| Recoatable | After 4 to 6 hours at 20 °C |
| Storage | Airtight, frost free, out of direct sunlight, use within 6 months of purchase |
- Stir. Prep Coat is ready to use, it only needs a thorough stir.
- Start with the ceiling, then move on to the walls.
- Begin at a window and work away from the light.
- Work wet on wet, even when cutting in. Otherwise visible lines and a picture framing effect may appear once limewashed.
- Blend your strokes. Merge vertical strokes with horizontal ones without loading more paint, and finish each wall in one go.
Prepare the paint and test the colour
- Stir thoroughly, for example with a mixing paddle, and decant into a suitable bucket. No pigment should remain in the original container.
- Keep stirring regularly throughout painting.
- Do not thin the paint. If the surface is too dry and absorbent, dampen the surface, not the paint.
- Choose your brush. The 4 × 14 cm block brush is an all-rounder for every wall.
Test your colour on a board of the same material or a discreet spot, such as behind furniture. A sample painted straight onto the wall may stay visible, so give it an irregular shape with feathered edges. On a wall with Prep Coat you can sample directly, then cover the samples with another coat of Prep Coat once you have chosen.
When wet, limewash looks darker and more transparent. Do not add more paint to compensate, the colour lightens and becomes opaque as it dries.
Exterior: facades, render, brick and stone
Raw render, brick and stone are ideal for limewash. The porous surface absorbs it well and the wall stays breathable. No primer or Prep Coat is needed.
- Clean the surface with a brush, removing dust, dirt and loose material.
- Dampen a dry, very absorbent surface with clean water, using a brush or a light mist spray.
- A painted facade should be repaired, dusted, sanded if glossy and coated with thin acrylic render for the limewash to bond to.
- A sealed facade in a highly exposed location is not suitable for limewash.
| Conditions | Paint? |
|---|---|
| 8 to 30 °C | Ideal |
| Below 5 °C (air or surface, during application or curing) | No |
| Hot direct sun, strong wind | No |
| Rain within the next 3 days | No, or protect the surface |
Curing takes longer in cold and humid conditions.
How much you will need
| Surface | Product | Coverage per coat | Coats |
|---|---|---|---|
| Raw render | Limewash | 7 to 10 m² / l | 2 to 3 |
| Drywall with Prep Coat | Limewash | 10 to 15 m² / l | 2 |
| Painted or sealed wall | Prep Coat | 6 m² / l | 1 |
Figures are a guide only, actual coverage depends on how absorbent your surface is. We recommend a sample for an accurate estimate.
Checklist: are you ready?
Tick everything off before you dip the brush.
Frequently asked questions
Can I apply limewash over old paint?
Yes, as long as it is in good condition and properly prepared. Lightly sand gloss paint and apply 1 coat of Prep Coat. If there are repairs or stains, apply 2 coats of water-based primer first.
Is Prep Coat the same as a primer?
No. It is a preparatory paint that creates an absorbent base for limewash. It does not even out stains or absorbency differences, that is what a primer is for.
Do I need Prep Coat outdoors too?
No, it is for interior use only. Raw render, brick and stone need no primer, and a painted facade needs a coat of thin acrylic render.
How long does limewash take to dry between coats?
Allow 1 to 2 hours per coat, longer in colder weather.
Why are joints or repairs showing through?
Because different areas absorb differently and limewash hides nothing. Even out absorbency with 2 coats of water-based primer, then apply Prep Coat.
Will limewash fade in the sun outdoors?
The pigments in Bauwerk limewash are mineral based, colourfast and UV stable.
Your surface is ready. What next?
Now comes the fun part: application. We cover brush technique and layering in How to apply limewash.
Need advice on a specific wall? Send us a photo of your surface at info@epix.plus or call +420 775 312 258. Colour samples can be seen in our showroom by appointment.
Source: the technical information in this article is based on manufacturer guides by © Bauwerk Colour: