Plastering Thickness Guide

Plastering thickness refers to the amount of plaster applied to a surface during the plastering process. The thickness can vary depending on several factors, including the type of surface being plastered and the desired finish.

In general, the recommended thickness for traditional plastering is around 10 to 15 millimeters (0.4 to 0.6 inches). This thickness is suitable for most interior walls and ceilings. However, for areas with higher risk of impact or moisture, such as bathrooms or external walls, a thicker plaster layer of around 20 millimeters (0.8 inches) may be recommended.

It’s important to note that plastering thickness can also depend on the type of plaster being used. For instance, lightweight plasters may require a slightly thicker application to achieve the desired finish, while some specialized plasters designed for specific purposes may have their own recommended thickness.

Additionally, it’s crucial to follow local building codes and regulations, as they may provide specific guidelines on plastering thickness based on the intended use of the surface.

If you’re unsure about the appropriate plastering thickness for your specific project, it’s best to consult with a professional plasterer or a local building authority to ensure compliance with the relevant standards and requirements.

The thickness of plastering (plaster thickness) depends on the type of plaster, the surface being plastered, and the desired finish.

  • Interior plaster is typically applied in a single coat of 12-15mm thickness.
  • Exterior plaster is typically applied in two coats, with the first coat being 10-12mm thick and the second coat being 6-8mm thick.
  • Plaster of Paris is a type of plaster that is typically applied in a single coat of 2-3mm thickness.

The desired finish can also affect the thickness of the plaster. For example, a smooth finish will require a thinner coat of plaster than a rough finish.

In general, it is important to follow the manufacturer’s instructions when applying plaster. This will ensure that the plaster is applied correctly and that it will last for many years.

Here are some additional tips for plastering:

  • Make sure the surface is clean and dry before you start.
  • Use a sharp trowel to apply the plaster evenly.
  • Work in small sections at a time.
  • Allow each section to dry before moving on to the next one.
  • If you are using a two-coat system, allow the first coat to dry completely before applying the second coat.
  • Smooth out the final coat with a damp sponge.

With a little care and attention, you can easily achieve a smooth, professional finish with plaster.

What is plastering in construction? – Plastering is a process of applying one or more coats of mortar to a concrete surface, brickwork, stone masonry or lathing. It must be durable such that it resists the penetration of moisture and should be able to weather uniformly. It should also be pleasing in appearance. These properties depend upon materials used, composition of mix, and degree of mechanical bond between the plaster and the backing surface and workmanship.

The walls shall be prepared as above and rendered with a mortar of cement and fine sand in specified proportions. At suitable intervals, 15 cm x 15 cm mortar squares to full thickness of base coat shall be first laid to serve as a guide to ensure a plane, smooth layer of plaster over the entire surface of the wall.

The mortar shall be dashed against the surface to be plastered with considerable forced, and shall be thoroughly worked into all joints and other surface depressions, to ensure a permanent bond. The plaster surface will be roughened and not beaten.

Coats for plastering

  • Scratch coat: The thickness of this coat should approximately 10 mm to 12.5 mm and must be laid over the full length of the wall or the natural breaking points like doors and windows.
  • Base coat (In case of thick plaster): The surface of scratch coat should be dampened evenly before base coat is applied. This coat is about 10 mm thick depending upon the overall thickness and then roughened with a wooden float to provide bond for the finishing coat. The second coat must be dampcured for at least seven days and then allowed to become dry.
  • Finishing coat: Before this coat is applied, the base coat is dampened evenly. Joints should be avoided and the finishing coat should be applied in one operation with thickness not exceeding 6 mm.

External Plaster: The external plaster is made in richer cement mortar proportion than the internal plaster. It is usually done in two layers. First layer is of 10 to 12.5 mm and final layer is of 6mm thickness. Waterproofing compound may be added in case the plaster is exposed to severe wet conditions. The finish can be of the type specified.

Internal Plaster: The internal plaster is usually done in single layers of 12.5 mm.

Plastering Thickness – Thickness of Plastering (plaster thickness) is usually 12mm, i.e.; 0.5 Inch / nearly Half Inch. The recommended thickness of cement plastering is given below.

  • Recommended thickness of plastering for brick walls is 12 MM, 15 MM or 20 MM.
  • Recommended thickness of plastering for RCC surface is 6 MM and 10 MM.
  • 10 MM thick cement plaster is done underside of the RCC ceiling/ roof.
  • 12 MM thick cement plaster is done where the plain surface of brick masonry is plastered.
  • 15 MM cement plaster is required on the rough side of 9” and 4.5” wall.
  • 18 MM thick cement plaster with neat cement slurry is required for making ‘Dado’ with the cement concrete flooring.
  • 20 MM thick cement plaster is done in two coats in some cases on rough side of wall or according to the design requirement.
  • 6 MM thick cement plaster is done on the RCC surface where it is required.

This article is sufficient for all the following queries -:

  • what is the standard thickness of plastering?
  • what is the thickness of plastering?
  • how thick is plaster?
  • how thick is plaster on a wall?
  • how thick is wall plaster?
  • how much cement is required for plastering?
  • how thick can plaster be applied?
  • how thick can plaster be?
  • how thick is plaster wall?
  • how thick should plaster be?
  • what thickness should plaster be?
  • how thick are plaster walls?
  • how thick can you plaster?
  • how thick can you plaster a wall?
  • how thick is a plaster wall?
  • how thick should plaster be on walls?
  • what is plaster in construction?
  • what is plastering in construction?
  • what is the ratio of cement plaster?

Plastering Thickness F.A.Q.

what is the standard thickness of plastering?

The standard thickness of plastering is 12-15 mm (0.4 – 0.6 inch) for internal walls and 15-20 mm (0.6 – 1.0 inch) for external walls.

how thick is plaster?

The thickness of plaster can range from 6 mm to 25 mm, depending on the type of plaster and the surface being plastered. For internal walls, a thickness of 12-15 mm is common, while for external walls, a thickness of 15-20 mm is more common.

what is the ratio of cement plaster?

The ratio of cement to sand in cement plaster is typically 1:4. If you’re using 1 bag of cement than 4 bag of sand will be used for plaster.

what is plastering in construction?

Plastering is the process of applying a thin layer of plaster to a wall or ceiling to create a smooth, even surface. Plaster is a mixture of sand, cement, and water, and it can be applied by hand or machine.

About the Author
Er. Mukesh Kumar
Er. Mukesh Kumar is Editor in Chief and Co-Fonder at Civil Engineering Website. Mukesh Kumar is a Bachelor in Civil Engineering From MIT. He has work experience in Highway Construction, Bridge Construction, Railway Steel Girder work, Under box culvert construction, Retaining wall construction. He was a lecturer in a Engineering college for more than 6 years.