Acceptance of repair work: how to check the quality of plaster?

For any building or renovation project to have a smooth, long-lasting, and visually appealing finish, plaster work quality must be guaranteed. As a homeowner or project manager, understanding how to assess the quality of plaster can prevent future issues and extra expenses.

When evaluating plaster work, there are a number of important factors to take into account. Every little detail, from the surface’s levelness to the plaster’s adhesion to the walls, is vital to the final result. Effective workmanship evaluation can be achieved with the use of basic tools and techniques.

This post will walk you through the crucial procedures and advice for examining plaster work. Knowing what to look for will help you request or accept plaster work modifications with confidence and guarantee a high-quality finish for your space.

Requirements for the quality of various types of plastering work

Appendix No. 8 of SNiP No. 3.04.01/87 and GOST No. 28013/98 "Building solutions" both include these requirements. These documents state that the plastering mixture needs to fulfill the following requirements:

• the mixture used for spraying or priming is sifted through a sieve with cells no larger than 3 mm;
• mixture for covering or single-layer plaster – through a sieve with cells no larger than 1.5 mm;
• solution mobility – from 5 to 12 cm;
• delamination level – up to 15%;
• the water retention rate of the mixture is at least 90%;
• the strength of the coating is determined by the values ​​included in the project.

Should the plaster mixture be bought directly from the manufacturer, it must be accompanied by documentation attesting to its quality.

The following details are included in these papers:

• date, exact time of preparation of the solution;
• brand of plaster mixture;
• type of binder used;
• overall volume;
• mobility indicator;
• name of GOST to which the mixture corresponds;
• price per cubic meter of purchased batch.

Evaluation of the surface after plastering

Deviations listed in Appendices Nos. 9 and 10 of SNiP No. 3.04.01/87 are acceptable for superior plastering work:

• surface deviation horizontally and vertically – 1 mm per 1 meter, along the entire wall in the room – no more than 5 mm;
• on 4 sq. meter there should be no more than two irregularities with smooth outlines, the depth of which is up to 2 mm;
• deviation from the plane of slopes, arches and pillars must be within 1 mm vertically and horizontally;
• permissible error of curved elements from a given design – no more than 5 mm;
• the width of plastered slopes may differ from the design one by no more than 2 mm;
• the error in the deviation of the rods from the straight axis between the angles of their intersection and bracing does not exceed 2 mm.

It is more convenient to use a pattern and a laser level to perform all kinds of quality checks on plastering work.

Flatness

After plastering, the wall’s evenness is examined with a laser level and a rule. Method of measurement:

1. Applying the rule horizontally to the wall, check that there is no gap between it and the surface. To measure the size of the existing gap it is convenient to use a laser level.
2. To determine vertical evenness, you must turn on the vertical axis construction mode on the level. First, a vertical line is drawn on the surface. Then the device is applied at an angle of 45 degrees to the surface. If the laser line is straight, then the surface itself is smooth. When the laser deviates from the drawn one towards the level, there is an influx of plaster on the wall; when it deviates to the side from the device, there is a concavity. The size of the irregularity corresponds to the distance between the drawn line and the laser.

The quality of the solution and the correct application of layers

Three steps are involved in the plaster solution’s quality control process:

• preparatory;
• at the time of application;
• during acceptance of completed work.

During the planning phase, consideration is given to:

• the quality of the prepared solution;
• wall humidity, room temperature;
• cleanliness of the surfaces on which the plaster will be applied;
• priming walls, selecting a priming solution.

One or more layers of any kind of plaster mortar, whether it be cement or lime-cement, can be applied. The manufacturer specifies the acceptable amount in the solution’s instructions.

When using multi-layer solutions, each layer should be less durable than the one before it.

Plaster mesh selection and requirements are governed by SP 71.13330.2017 and the project itself. Working without a plaster mesh is permitted when working with gypsum mixtures.

We would like to offer you a video to watch on the subject of "Minimum and maximum layers of plaster":

Adhesion

GOST 31356-2007 contains the plaster adhesion requirements. With the use of a specialized tool called an adhesive meter, you can determine how strongly the layer adheres to the base. It is capable of computing clamping forces between 0 and 10 kN. The force required to rip off or separate the layer in a direction perpendicular to the base is indicated by this indicator.

When examining plaster work, begin by looking for any obvious defects such as bubbles, cracks, or uneven areas on the surface. These problems may be a sign of subpar application or deeper issues. It can also be helpful to run your hand over the surface to find any irregularities that might not be immediately apparent.

Next, check to see if the plaster is properly attached to the wall. Gently tap with your knuckles on the surface. A hollow sound could be a sign of improper plaster bonding, which could cause problems down the road. This is essential to guaranteeing the plaster’s long-term durability.

The plaster’s thickness is another crucial factor to examine. It ought to be uniform throughout the surface. Verify that the thickness complies with the contractor’s specifications by using a depth gauge or other straightforward measuring device.

Lastly, think about the plaster’s overall finish and drying time. Plaster that has dried properly shouldn’t exhibit any indications of moisture or discoloration. Smoothness and preparation for painting or other final treatments should be the order of the day.

These guidelines will help you achieve excellent plaster work, which will improve the overall durability and aesthetics of your walls. It will save you future headaches and extra expenses if you take the time to carefully inspect the plaster.

It’s critical to verify quality before accepting plaster repair work. This can be done by looking for even, smooth surfaces free of visible flaws or cracks, making sure the plaster adheres to the walls properly, and making sure the thickness of the plaster satisfies project requirements. Verifying the workmanship can also involve checking the edges and corners for neatness and tapping the walls to test for soundness.

Video on the topic

How to check the quality of plaster from a contractor. Apartment renovation in Tyumen.

Is this how they check the QUALITY of plaster?? Checking the quality of plaster according to SNiP.

Checking the quality of plastering work when accepting an apartment in a new building