What is the difference between skimming and plastering?
Skimming and plastering are both techniques used in wall finishing, but they differ in their purpose and application. Here are the main differences between skimming and plastering:
- Purpose:
– Skimming: Skimming is a technique used to achieve a smooth and even surface on an already existing wall. It involves applying a thin layer of finishing plaster, also known as skim coat, to cover imperfections, such as small cracks, bumps, or unevenness in the wall.
– Plastering: Plastering, on the other hand, involves applying multiple layers of plaster to create a new surface on bare walls or over a base material like brick, concrete, or plasterboard. Plastering is used to create a solid and durable wall finish, providing structural strength and aesthetic appeal.
- Thickness:
– Skimming: Skimming involves applying a very thin layer of plaster, typically around 2-3mm thick. The purpose is to create a smooth and level surface without adding significant thickness to the wall.
– Plastering: Plastering involves building up multiple layers of plaster, each typically around 10-15mm thick, to create a solid and substantial wall surface.
- Surface Preparation:
– Skimming: Skimming is typically done on already existing walls that may have minor imperfections. Before skimming, any loose paint, debris, or wallpaper is removed, and the surface is cleaned and repaired as needed.
– Plastering: Plastering is often done on new construction or when completely reworking walls. It requires a base material, such as brick, concrete, or plasterboard, which is properly prepared by ensuring a clean, stable, and suitable surface.
- Application Technique:
– Skimming: Skimming involves the application of a thin layer of finishing plaster using a trowel or a specialized skimming tool. The plaster is spread evenly across the wall surface, and any excess is smoothed out.
– Plastering: Plastering requires a more comprehensive application process. It involves applying multiple layers of plaster, allowing each layer to dry before applying the next. Each layer is applied with a trowel and then leveled and smoothed to create a uniform surface.
In summary, skimming is a technique used to create a smooth finish on existing walls, while plastering involves building up layers of plaster to create a new wall surface. Skimming is thinner, applied to fix minor imperfections, and requires less preparation, while plastering is thicker, applied to create a solid wall structure, and requires more extensive surface preparation and application techniques.