Specific weight of plaster and a table for calculating volumetric weight
Leveling walls inside and outside a building is a complex and labor-intensive process. Moreover, the final result directly depends on the material used by the worker. The construction materials market offers a wide range of plaster mixes. The most common are:
- Gypsum-based.
- Lime-based.
- Cement-based.
- Combined mixes (a combination of two or more types).
When choosing the right material, it is necessary to take into account the functional features of each type.
Calculating material costs for dry mixes.
At the very beginning of plastering work, both a professional and an amateur need to determine the amount of material required for successful work. A mandatory condition for achieving a quality final result is to follow all the features of the technological process. Calculations can be shown using such a parameter as the weight of dry plaster:
The average weight of one square meter of plaster is 15 kg. To calculate a more exact value, this weight must be multiplied by the layer thickness. An approximate calculation is shown below in the table.
| Plaster thickness | Weight of 1 m² (kg) | Specific weight (kg/m³) |
| 1 cm | 15 | 1500 |
| 2 cm | 30 | |
| 3 cm | 45 | |
| 4 cm | 60 | |
| 5 cm | 75 |
| Criterion / Plaster mortar | Gypsum-based | Lime-based | Cement-based |
| Vapor permeability | 0.11-0.14 mg/(m·h·Pa) | 0.10-0.12 mg/(m·h·Pa) | 0.09 mg/(m·h·Pa) |
| Consumption per 1 m² with a thickness of 1 cm | 8.5-10 kg | 12-20 kg | |
| Working setting time | 1.5 hours | 2 hours | |
| Working conditions | optimal conditions must be maintained | resistant to water and air exposure | |
| Need for puttying | not required | required | |
| Moisture resistance | none | present | |
| Bactericidal properties | does not have | has | |
| Strength | high | not high | |
| Versatility (interior and exterior work) | no | versatile | |
Based on the data provided, it can be said that all types of mortars have a number of advantages. They allow vapor to pass through well, without creating a “steam room” effect. There are also nuances during work: for example, gypsum has to be mixed more often and in small portions, because it dries faster. Cement plaster can increase the heat capacity of a room, which is a significant advantage. When working in damp rooms, a moisture-resistant mortar must be used.
As for cost, it varies depending on material consumption. Thus, the specific weight of cement-based plaster is twice that of gypsum plaster, so the weight of plaster per 1 m² will differ. The price of gypsum mortar is higher, which means there will be no significant difference in cost compared with a cement-sand mix.
Frequently Asked Questions
Can the density of plaster be used for precise calculations?
The density and weight values for plaster in this article are reference values. They are suitable for preliminary estimates, but design, construction, production and other critical calculations should be checked against standards, material datasheets or measurement results.
Why can the actual weight of plaster differ from the table?
The actual weight of plaster depends on composition, moisture, temperature, porosity, fraction size, material grade and measurement conditions. Because of this, real values may differ from the average table data.
How do you calculate the mass of plaster from density?
For an approximate calculation, use the formula: mass = density × volume. If the density of plaster is given in kg/m³ and the volume is in m³, the result will be in kilograms.