Simple Water Absorption Test
How to test if a surface has the right absorbency for limewash paint
Why test Absorbency?
Limewash paint requires a certain level of absorbency to adhere properly. If a surface absorbs moisture unevenly—due to repairs, patches, or gypsum board panels—it can result in a patchy or inconsistent finish. A simple water absorption test helps determine what type of preparation your wall needs before applying limewash.
This is the right guide for you if you want to learn how to:
- Ensure your indoor surface has the correct absorbency for limewash.
- Identify and fix any uneven absorption before painting.
This test is not suitable for exterior surfaces or raw masonry. See our Surface Guides for more information.
How to Test Surface Absorption
What You'll Need:
• Clean water
• A brush or damp sponge
How to Test:
01 Brush or sponge water evenly across the surface you want to test.
02 If testing gypsum board, ensure you are applying water across repaired areas or joints.
What to Look For:
Water is not absorbed, or dries slowly but evenly:
The surface is sealed or has low absorbency. Your surface should be prepared with 1 coat of BAUWERK Prep Coat prior to limewashing.
Water dries Fast and evenly:
The surface has high absorbency. Apply 1 coat of BAUWERK Prep Coat followed by Limewash Paint.
Uneven drying (showing patches or visible repairs):
The surface has inconsistent absorbency and requires a water-based sealer/undercoat to even it out and prevent "ghosting" of repairs or panel outlines. Once this has been applied you can apply one coat of BAUWERK Prep Coat for proper adhesion.
View Surface Guides
for more application details based on the material you're painting