Mixed + Repaired Surfaces Guide
Walls made of mixed materials, like half brick and half plasterboard, or those that have been repaired, may absorb limewash differently based on each material's absorbency. The correct surface preparation for your materials and setting will create a more consistent final finish.
This is the right guide for you if you want to learn how to:
- limewash a surface that has been repaired
- limewash a surface made up of different substrates
- prepare your surface before limewashing
- apply limewash paint
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.
The coverage of Limewash Paint over Raw Absorbent walls is 7–10 m² per litre, per coat, with 2 coats required.
Interiors Only
The coverage of Limewash Paint over Bauwerk Prep Coat is 10–15 m² per litre, per coat, with 2 coats required.
The coverage of Bauwerk Prep Coat over Previously Painted walls: 6 m² per litre, per coat, with 1 coat required.
Exteriors Only
The coverage of Limewash Paint over Previously Painted/Sealed walls is 15–20 m² per litre, per coat, with 2 coats required.
*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.
Materials used to fill or patch damaged walls will have varying absorbency levels compared to the rest of the wall. To ensure a consistent finish across the entire wall surface, we recommend sealing the patched or repaired areas. In cases where the wall has undergone significant repairs, it may be best to seal the entire wall. The primer prevents the "ghosting" of repaired areas from being visible through the finished paintwork and creates a more uniform look, especially if your walls are made of mixed substrates.
Interior Repaired Surface Preparation
Step 1: For internal walls, apply 2 coats of a water-based undercoat-sealer/primer to ensure a consistent surface.
Step 2: Apply 1 coat of Bauwerk Prep Coat
Exterior Repaired Surface Preparation
Step 1: We recommend applying a coat of a thin acrylic render product. For exterior render that needs patching or repairs, use a mineral render product. This will provide an absorbent layer for the limewash to adhere to on the wall. If limewash is painted over a sealed or non-absorbent exterior wall exposed to the elements, you can anticipate a shorter maintenance period.
When applying limewash on a wall made with mixed substrates/materials, you may notice variations in colour across the surface due to differences in absorbency levels of the various materials. While this can add character to the space, if you prefer a more consistent appearance, you can adjust your preparation steps accordingly. Select preparation steps based on your desired outcome and surface location:
To Embrace Variation
If your previously painted walls have gloss paint, lightly sand.
Previously Painted Interior Walls: Apply 1 coat of Bauwerk Prep Coat.
Previously Painted Exterior Walls: Apply a coat of a thin acrylic render product.
Raw Absorbent Masonry Walls: No sealer or primer is required, just dampen walls with clean water using a brush or light mist spray to ensure easy application of limewash paint.
For a More Uniform Look
Your surface should be free from any dirt and dust.
Interior Walls | Step 1: Apply 2 coats of a water-based undercoat-sealer/primer to ensure a consistent surface. Step 2: Apply 1 coat of Bauwerk Prep Coat.
Exterior Walls | Step 1: Apply a coat of a thin acrylic render product before applying limewash paint.
- Stir the limewash well and make sure all pigment is thoroughly mixed into the paint. Do not paint from a full bucket. Decant into a larger vessel and work with only around 8cm (3in) of paint in a bucket.
- Continue to stir paint regularly while painting. We recommend a machine stirrer, like a Bamix stick blender, or an egg whisk.
- Ensure you have the correct brush for the job. Our 4x14 limewash block brush is our most popular size, perfect for all applications.
Step 3: Limewash
Apply 2 coats of Bauwerk Limewash Paint
- Dip the brush into the bucket and flick off excess paint. The brush can hold a lot of paint, but should not be dripping.
- Start in a corner of the wall–holding the brush at a right angle to the wall. It may be best to hold the brush on the brush body, rather than the handle for more control.
- Using loose, free strokes stretch the paint as far as possible, varying the direction of strokes constantly. Let the bristles do the work. There is no need to apply too much pressure.
- Brush out the paint evenly in a thin coat, preventing runs or drips, while covering every part of the surface in the first coat. Maintain a wet edge at all times to prevent lines in your finished surface*. Finish each coat in one continuous application. Do not try and patch walls once the coat is finished, as missed areas can be covered in the next coat.
- When wet, the colour will appear darker and transparent. Do not compensate for this by applying more paint. As the paint dries, the colour will lighten to the chosen colour and become more opaque.
- Allow a minimum of 1-2 hours between coats. Apply a second coat faster, wet-in-wet and a lot looser. Missing spots is okay, as the first coat should have covered everything. Allow the paint to dry.
If you're painting with our 'whites', maintaining a wet edge is not required. These colours patch easily and are great for spot touchups.
- There is no need for a sealer or additional top coat over the limewash. A third coat of limewash can be applied, based on your colour and coverage preferences.
- All brushes, tools, and containers wash out quickly with minimal water and without harm to groundwater.
- Following these steps ensures a natural, dust-free surface with a fantastic texture, making it easy to repaint and maintain.
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