16/07/2026
Why does paint blister when decorating? There's silk under that thick matt paint and painting over silk paint can come with its issue this is a common one 🤔
This is a perfect example of why preparation is just as important as the finish.
The wall in the photo has blistered because it was previously coated in vinyl silk paint. Silk creates a smooth, almost plastic-like surface that doesn't give new paint anything to grip onto.
When fresh water-based paint is applied: 🔹 Moisture sits on the surface instead of soaking in. 🔹 The new paint begins to dry and shrink. 🔹 Because it can't bond properly to the old silk coating, air or moisture becomes trapped beneath the surface. 🔹 The result? Blistering and bubbling like you see here.
In some cases, heat, condensation, or poorly prepared plaster underneath can make the problem even worse.
This is why a professional decorator doesn't simply paint over the problem.
The correct process is to: ✔️ Identify the cause of the blistering. ✔️ Remove all loose and failed paint. ✔️ Sand the remaining silk to create a good key. ✔️ Apply the correct stabilising or adhesion primer. ✔️ Fill, sand, and prepare the surface before applying the final coats.
Skipping these steps might save time today, but it often leads to paint failure and costly redecoration later.
Preparation is what separates a finish that lasts for years from one that starts failing within weeks.
Have you ever started painting and found bubbles appearing on the wall? Let us know in the comments!
