Fixing White Patches on Limewash Walls

White patches or spots usually appear when limewash paint is applied too thickly, preventing it from curing properly. This causes the lime to ‘bloom’ on the surface, leaving white patches and making it powdery, so it comes off easily when touched. For best results, apply limewash in thin coats using an absorbent bristle brush.  Spread the paint out as far as it will go, without overworking it. Curing takes about two weeks, so avoid rubbing the walls during this time to prevent marking.

Mineral-based limewash, like Bauwerk Colour, requires a moderately absorbent surface. When a surface is non-absorbent or absorbs too little, proper preparation must be undertaken to create the right conditions for the limewash paint to penetrate.

If painting over a sealed or non-absorbent surface, such as a wall previously painted with standard acrylic house paints, lime blooming is more likely to occur, as it is more difficult to avoid over-application of limewash. We recommend using Bauwerk Prep Coat as an important step in surface preparation when limewashing previously painted or sealed interior wall surfaces. 

For external surfaces that have already been painted or sealed, we recommend applying a fresh cement-based absorbent thin coat render (used externally or internally) to create a surface for limewash paint to penetrate.

Fix 1. To cover white patches from over-application, simply wait 24 hours and apply an additional thin coat of limewash paint. 

• Our paint must be applied by spreading it as far as it will go without overworking it. When painting your clouds, make sure to paint until it feathers out on the edges. This is a good indicator that the paint has been stretched.
• A quick tip to ensure your coats are consistent is to have a look side-on from where you have just painted. With the glare, you can see if there are areas with too much product.
• Be mindful to have the "right" amount of paint on your brush for the area or cloud you will be painting. Too little will also make it difficult to spread before it dries.  Dip the brush 2.5 cm into the limewash, flick it once with your wrist into the bucket, and then you are good to go. This amount of paint should cover around 1m² of wall over the Prep Coat.
• Please note that you may see less textural variation and a flattening of the wall colour with the addition of a third coat of limewash.

Fix 2. Using a bucket of clean water, dip your brush 1cm into the water, after every 3-4 times that you have taken limewash paint onto your brush. This helps stop the edge of your paint from drying too quickly.

Tip: Make sure your limewash brush is in good condition – not too dried out and clean of old paint etc.