Bubbling, blistering, and localized hollow areas are common problems encountered during gypsum plaster application. When bubbles appear on the wall, the first reaction is often: “Is there something wrong with the gypsum plaster?” However, in many real construction projects, bubbling is not necessarily caused by the gypsum material itself. In many cases, the actual causes are related to substrate absorption, substrate preparation, application thickness, and plastering techniques. This is especially important when working on concrete walls, aerated concrete blocks, or brick substrates. If the substrate is too dry or absorbs water too quickly, the water in the gypsum slurry can be rapidly drawn into the substrate, making it difficult for trapped air to escape. The result can be bubbling, blistering, or even hollow areas. So, how can gypsum plaster bubbling be reduced? Here are four practical steps worth paying attention to. Step 1: Moisturize and Seal the Substrate — The Most Importa...
One of the biggest challenges in gypsum plastering is: Bubbles, blisters, and even hollow areas appearing shortly after application. Many contractors immediately ask: “Is the gypsum material causing the problem?” However, based on real construction experience: Many bubbling issues are not caused by the gypsum itself, but by improper substrate preparation. A dry wall surface, excessive water absorption, and trapped air inside substrate pores can all lead to bubbling after plaster application. So how can we effectively reduce gypsum plaster bubbling? Remember these 4 important steps: 1. Moisturize and Seal the Substrate Proper substrate preparation is essential before plastering. For concrete walls, pre-wet the surface and keep it damp without visible water. Then apply a suitable bonding agent before plastering. For AAC blocks or brick walls, sufficient pre-wetting is required to prevent rapid water absorption from the gypsum plaster. 2. Keep the First Coat Thin Do not try to achiev...