1. What are the advantages and disadvantages of cement and gypsum as machine-sprayed materials?

Both cement and gypsum can be used as machine spraying materials. From the point of view of performance, the strength of gypsum matches the general base wall, and there will be no problems of cracking and hollowing of cement mortar. From the perspective of energy saving, the energy consumption of gypsum is only 1/3 of that of cement, and the carbon dioxide emission is only 1/10 of that of cement.
Then from the perspective of environmental protection, gypsum has many environmental protection features such as light weight, heat absorption, sound insulation, flame retardancy, and assisted breathing. And can be recycled infinitely. It is in line with the country’s strategic goal of developing energy-saving and environmental protection industries.
Gypsum mortar is used for 90% of interior wall plastering in developed countries, and gypsum mortar is also the development direction of domestic plastering materials. From the market price point of view, cement mortar is low, generally ¥200-300. Gypsum mortar is expensive, and the price of foreign machine sprayed gypsum mortar is around ¥2,000. Domestic machine-sprayed gypsum mortar is only about ¥1,000. Although the price of gypsum mortar is not as good as that of cement, comprehensive factors such as later maintenance costs and environmental protection benefits are considered. As an interior wall plastering material, gypsum mortar is superior to cement mortar in performance. It can improve the quality and grade of interior wall decoration.

2. What kind of wall is suitable for gypsum mortar? Where can it be used?

Gypsum machine blasted mortar is suitable for all types of masonry and concrete. It can also be plasterboard, insulation boards, and old plaster and latex paint coatings that have been treated during renovation work. However, it cannot be applied directly to wood, plastic, glass, and metal-based walls.
Machine-sprayed gypsum mortar is mainly used for plastering indoor partition walls, interior walls and ceilings, and can also be used as the bottom plastering of kitchen and bathroom. Because of its hygroscopicity and temperature-regulating effect, gypsum is generally not used on exterior walls.

3. Will the wall crack and hollow after spraying gypsum mortar?

The cracking and hollowing of the plaster on the interior wall is a problem that everyone is more concerned about. The gypsum mortar will not appear cracking and hollowing. Mainly because:
First, machine-sprayed gypsum mortar is generally produced with compound additives. So as to increase the adhesion between gypsum mortar and the base layer, change the elastic mold of gypsum. And make it match the aerated concrete block. Reduce the shrinkage rate of plastering gypsum, increase the water retention rate of gypsum, so as to prevent cracking and hollowing.
Second, machine-sprayed gypsum mortar is sprayed onto the wall after being accelerated by compressed air, which has a certain rebound force. This means that the wet mortar adheres very well to the substrate. Wet mortar is continuously sprayed onto the wall with good continuity. Effectively prevent the risk of hollowing and cracking of the wall.
Third, before spraying construction, it must be at the junction of the base wall material. And install alkaline mesh cloth one-third of the distance from the plastered surface to prevent hollowing and cracking.
Several questions about machine-sprayed gypsum mortar (2)
Several questions about machine-sprayed gypsum mortar (3)