Wall Putty Keeps Bubbling? 15 Causes + 11 Fixes to Save Your Project!

 Putty is a foundational layer in wall finishing systems, used to level the surface and ensure perfect paint adhesion. However, during construction, bubbling often occurs—damaging the appearance, weakening paint performance, and potentially releasing harmful substances. This article will give a complete overview of the 15 common causes of wall putty bubbling and 11 effective solutions to help you avoid or fix the issue like a pro.

Part 1: 15 Common Causes of Putty Bubbling

1. Uneven mixing, leaving undissolved powder particles in the putty.

2. Too much water or overly wet mixture prolongs drying time.

3. High moisture content or inconsistent base density causes poor ventilation, trapping air inside.

4. Micropores in the base surface, trapping air during application.

5. Overly dense substrates (e.g., high-grade concrete) with poor breathability.

6. Thick single-layer application doesn't allow air to escape fully.

7. Rough or unpolished surfaces, causing uneven application and trapped air.

8. Low absorption substrates like formwork tops—air can't escape.

9. High temperatures cause rapid drying and surface bubbling.

10. Excessively damp walls, delaying drying and increasing bubbles.

11. Overuse of cellulose additives, making the layer too airtight.

12. Low water absorption substrates, keeping putty wet for too long.

13. Incorrect or missing primer, resulting in poor bonding and sealing.

14. Delayed bubbling after drying due to undissolved particles swelling.

15. Improper tools or technique, failing to press and release air effectively.

Part 2: 11 Solutions to Fix Putty Bubbling

1. For small bubbles: Pierce them and reapply a thin coat of putty.

2. For large areas: Remove the bubbled layer and reapply suitable putty.

3. Rough bases: Use coarser putty for the first coat to fill gaps better.

4. Pre-clean the wall: Remove dust, grease, and loose material.

5. Apply primer or bonding agent: 1–2 coats to enhance adhesion.

6. Pre-wet dry walls: Especially under sunlight or wind; wait till no visible water before applying putty.

7. Proper mixing process: Mix well, let stand for 10 minutes, then remix before applying.

8. Firm application technique: Press and re-smooth to expel trapped air.

9. Pre-treatment for dense surfaces: Wet the surface first, apply primer, then rough gypsum before finishing with putty.

10. Thin application: Keep each layer under 1mm to avoid bubbling and delamination.

11. Avoid construction during high humidity: Stop work if RH >75% or wall moisture >10%.

Quality wall finishes start from the base. With correct material choice, careful base preparation, and professional application, bubbling can be easily prevented or fixed. Don’t let small mistakes ruin your big project.