Brick Surface Guide

When working with an an unpainted, breathable surface like brick, it is best to apply limewash paint samples to a separate piece of the same material or a discreet, hidden area. Sampling directly on the surface may leave a visible patch.

For internal brickwork you have a few options:

Option 1:

Remove the existing paint layers through methods like sand or ice blasting, or chipping off. This is typically an expensive process and creates a lot of dust. If you don't need a paint-free surface consider exploring Option 2.


Option 2:

Leave the existing paint layers as part of the history of the wall. Glossy paint layers should be slightly sandpapered to remove the gloss, but it is not necessary to remove the paint entirely. Then continue the preparation steps as outlined in our Surface Preparation and Application guide above.

Things to consider: Limewash paint works best on absorbent surfaces. In situations where there's a mix of absorbent and non-absorbent areas, such as a wall with paint on some parts and not on others, the final color may show variations, appearing lighter or darker where it has been absorbed differently.

Additionally, most of the painted surfaces have no or very little absorbency. That may result in lesser adherence to the paint where people come in direct contact with the wall.

For better adherence and a more uniform finish, we would recommend preparing your walls with 2 coats of a water-based undercoat-sealer/primer and 1 coat of Bauwerk Prep Coat.

Historically, whitewash was a lime and water-based coating that was white in colour. However, more recently the term 'whitewash' is used more generically and often refers to painting with a watered-down conventional paint. So, if comparing generic 'whitewash' to Bauwerk's limewash paint there are many differences. Bauwerk paint is made from distinct materials (clay, minerals and natural pigments) compared to conventional paint which contains plastics. The result and benefits are therefore very different.

If we're speaking specifically about Bauwerk products and comparing our Whitewash to our Limewash...they are one and the same! Bauwerk Colour's Whitewash, is simply a pure white limewash paint colour in our palette. It's the same composition as the other 399 colours in our palette, other than of course its unique tone and value. It is one of our 8 'whites' alongside Chalk, Raw White, Bleached White which all have slightly tonal variations.

Bauwerk Colour's Transparent White is the only product in our range that does not contain pigment. This is the base limewash used together with pigments to create all of other limewash colours. This product is suitable for achieving a transparent wash with minimal texture, particularly for subtle effects over surfaces like brick.

Yes, Limewash is completely non-flammable, making it a great choice in fire-affected areas, and for use in and around chimneys and fireplaces. From a design perspective, you can apply limewash very subtly to tone down prominent brick colours, or cover the bricks all together with a more opaque finish. See our guide above for recommendations on colours and products when painting for purely decorative purpose. If the surface is exposed to heat and flames remove any pre-existing paint layers (if applicable) and paint the lime wash paint without any primers or sealers directly on to the masonry surface.

Yes! Cinder block is a very absorbent brick/block, which is great for limewash paint.

© Elle Critchley

Corrective instruction – uneven runoff marking on exterior limewash over brick

1. Identify and rectify the source of water run-off first.
   Check flashings, cappings, adjoining metalwork, soffit edges, window junctions and sealant details. Any recurring water path must be resolved before cosmetic rectification is attempted.
2. Allow the wall to dry fully.
   Do not assess or rework the finish while moisture is still present in the wall. The surface should be allowed to dry thoroughly and stabilise in appearance.
3. Clean the surface gently.
   Remove loose surface residue with a soft, dry masonry brush. If required, lightly wipe with clean water only. Avoid saturation, harsh scrubbing, pressure washing, acidic cleaners or detergents.
4. Carry out a small test area first.
   Trial the proposed cleaning and recoating method on a discreet section to confirm the visual outcome before proceeding across the full area.
5. Assess the substrate condition.
   Check for inconsistent absorbency, patch repairs, mortar residue, contamination, salts or other localised factors that may be contributing to uneven appearance.
6. Rectify the full affected section, not isolated stripes only.
   Limewash should be blended across the full wall section or natural break point. Localised spot correction alone is likely to remain visible.
7. Reapply limewash in thin, even coats.
   Once the substrate is sound, clean and dry, reapply in controlled, thin coats using a consistent application method. Avoid heavy build-up and avoid overworking partially drying areas.
8. Work only in suitable conditions.
   Do not apply in hot direct sun, strong wind, imminent rain or very cold conditions. Protect freshly applied work from early weather exposure during curing.
9. Review after curing.
   Final appearance should be assessed only once the limewash has dried and cured properly, as the finish will continue to settle visually during this period.

Corrective guidance and substrate absorbency checks prior to full application of limewash paint on exterior brick / masonry walls

1. Pre-start inspection

Before any new application or corrective work begins, inspect the wall and surrounding building details for conditions that may affect the finish:

• water run-off from flashings, cappings, soffits, window heads or metal edges
• leaking or failed junctions and sealants
• contamination, salts, tannins, dirt, mortar residue or patch repairs
• inconsistent background texture or previous coatings
• active dampness or moisture movement through the wall

Any source of recurring water entry or concentrated run-off must be rectified before limewash application proceeds.

2. Confirm substrate is dry and sound

Do not apply to damp or unstable surfaces.

The wall must be:

• dry through the face
• clean and sound
• free from loose material, dust and friable residue
• free from incompatible sealers or film-forming coatings

3. Clean down gently

Prepare the surface using gentle methods only:

• soft masonry brush
• light removal of loose residue
• minimal clean water only where required

Do not use pressure washing, acid cleaning, detergents, wire brushing or aggressive abrasion.

4. Carry out surface absorbency checks

Before full application across any elevation, test the absorbency of each substrate type and each wall area.

Simple site absorbency test

Apply a small amount of clean water by brush or light spray to several representative areas, including:

• main wall field
• repaired sections
• mortar-rich areas
• denser or smoother brick areas
• exposed and sheltered faces

Read the result

• Even, moderate absorption: suitable basis for consistent application
• Very fast suction: risk of rapid drying, lap marks and patchiness
• Very low or uneven suction: risk of flashing, poor bonding and visible variation
• Different behaviour between areas: divide into zones and adjust preparation/application method accordingly

Do not proceed with full application until absorbency behaviour is understood across all surfaces.

5. Prepare sample areas first

Complete a trial area on each distinct substrate or elevation before proceeding with the main works.

The sample should confirm:

• absorbency response
• brushing method
• coat rate
• drying behaviour
• expected finished appearance

Obtain approval of the sample area before full application.

6. Application requirements

Apply limewash in thin, even coats using a consistent technique.

Contractor to ensure:

• a uniform working method across the whole surface
• wet edges are maintained
• partially drying areas are not reworked
• heavy build-up is avoided
• application is taken to natural breaks where possible

Do not spot-apply isolated corrective patches unless specifically approved. Where correction is required, rework the full affected wall section or natural break point.

7. Suitable weather conditions

Do not apply in:

• hot direct sun
• strong wind
• imminent rain
• very cold conditions
• conditions causing excessively rapid or delayed drying

Freshly applied limewash must be protected from early rain and concentrated water exposure during curing.

8. Corrective action for streaking, runoff marks or uneven appearance

Where visible streaking, dark run marks or patchiness occur:

1. identify and rectify the water source or contributing building detail
2. allow the wall to dry fully
3. gently remove loose residue from the surface
4. test a small area before broader correction
5. assess whether uneven absorbency, salts, contamination or repairs are contributing
6. rework the full affected section, not isolated stripes only
7. reapply in thin, even coats under suitable conditions

9. Practical note for external work

Limewash is a natural mineral finish and will respond to variations in the substrate and the site environment. In exterior applications, weather exposure, water run-off and soluble substances such as salts or tannins may affect appearance over time. This is especially relevant on retaining walls, boundary walls and garden bed walls. Maintenance should be expected at intervals appropriate to the conditions on site.