What is putty for, how to prepare and apply it

In order to create a smooth and even surface that is ready for paint or wallpaper, putty is an essential step in wall decoration. Whether you’re finishing up new construction or remodeling an old wall, using putty correctly can have a big impact on how your room turns out.

You will learn the fundamentals of putty in this guide, including what it is, why it’s used, and how to get ready to apply it. We’ll also go over the best putty application methods so that your walls are ready for the next phase of your project.

Whether you’re an expert or a do-it-yourself enthusiast, knowing these basics will enable you to apply a beautiful finish to your walls. Let’s examine putty in more detail and discover how to make the most of this indispensable substance.

Purpose of Putty How to Prepare and Apply Putty
Putty is used to smooth out walls, fill small cracks, and create a flat surface for painting or wallpapering. Mix the putty with water according to the instructions until it reaches a creamy consistency. Apply it to the wall using a putty knife, spreading it evenly. Let it dry, then sand the surface for a smooth finish.

Before painting or applying wallpaper, putty is necessary to fill in tiny holes, cracks, and flaws on walls and create smooth, even surfaces. It’s critical to understand how to properly mix putty to the correct consistency and apply it in thin, even layers using the appropriate tools in order to achieve the best results. Achieving a professional finish requires careful surface preparation and patient application.

What is it

Putty is a building solution for leveling that consists of:

  • Fine-grained filler (sand, chalk, etc.).d.);
  • Binding agent (cement, gypsum, glue);
  • Optional – pigments and other functional additives (antifungal, decorative, surface structuring).

Application areas

What is the purpose of puttying walls? It should come as no surprise that puttying is the final step in surface pre-finishing. The aim is to achieve a flawlessly smooth wall or ceiling that is fully prepared for painting or wallpapering.

Why is puttying plasterboard walls necessary, considering their flawlessly smooth surface (see How to putty drywall qualitatively)?

It enables you to conceal the screw heads used to secure the drywall to the frame or lathing as well as the mounting seams at the joints between adjacent sheets. Furthermore, drywall is frequently puttied over the whole surface.

There are two objectives to this operation:

  1. To create a separating layer between kraft paper (the shell of the drywall) and the wallpaper. In this case, boring or worn-out wallpaper can be removed from the walls without damaging the drywall;
  2. Hide the seams at the joints between the drywall sheets cut on site (see. Puttying the seams of the drywall). If the factory edges PLUK (semicircular with thinning) allow you to hide the reinforcing seam material, then the joints of the additional sheets after reinforcement and puttying will stand out in thickness. However, it is worth applying a layer of putty about a millimeter thick over the entire area of ​​the drywall structure – and the seams will become absolutely invisible.

Furthermore, putty is frequently used to fix small holes and cracks in walls and ceilings. The resulting flawlessly smooth surface is prepared for additional finishing.

You can learn more about the uses and application of putty in this article’s video.

Putty or plaster

Mixtures for plastering are different from puttying mixtures in two ways:

  1. A larger filler, giving a much rougher surface;

  1. As a result – much less shrinkage during drying. After application, the plaster retains the original layer thickness. The shrinkage of the putty is especially noticeable when sealing seams and fasteners on plasterboard structures – they have to be puttied in 2-3 passes.

For this reason, these building mixtures’ application domains are distinct:

  • Rough leveling of the surface is always done with plaster. Its layer can reach 5 or more centimeters;

Nevertheless, the plaster needs to be reinforced with metal or fiberglass mesh if the thickness exceeds 30 mm.

  • Puttying involves applying a leveling layer no more than 5 mm thick, more often – 1-3 millimeters.

Types and features

A comprehensive inventory of every kind of putty available would be excessively lengthy, and in addition, the majority of the materials on this list—like wood or automotive putties—are not utilized in construction. As a result, we will only include the most widely used fixes.

Cement

Cement binder mixes are prepared right before use and are sold in dry form. After being mixed with water, the solution has a maximum shelf life of a few hours.

Crucial elements of cement putty:

  • High mechanical strength, allowing it to withstand abrasion and impacts;
  • Water resistance. Cement mixtures can be used in bathrooms, showers and for finishing the facades of buildings.

  • White cement mixtures deserve special mention. They do not require mandatory painting, and when painting, the base does not show through even when applying paint in one layer.

Gypsum

Gypsum binder inherently indicates that the mixture should only be used for interior design. Gypsum swells and softens in a humid environment, and it cannot claim to be water resistant. After mixing, it has a 30- to 60-minute lifespan.

Gypsum mixtures, however, can be used to finish bathtubs provided the finishing (wallpaper, paint, tiles, etc.) is waterproof. Furthermore, the space needs to have efficient ventilation.

Gypsum’s primary benefit—and the reason putties made of it became so popular—is how simple it is to grind. A hand float or a grinder fitted with a grinding mesh can be used to rectify puttying flaws.

Gypsum mixtures can be broadly classified into two categories based on the size of the filler fraction:

It’s interesting to note that the so-called universal putties have the same characteristics as finishing putties, but they can be applied in a slightly thicker layer—up to 1 centimeter per pass—because of their low shrinkage.

Acrylic

In contrast to the last two, acrylic putties are available for immediate use. When kept in sealed packaging, they have a minimum three-year shelf life. However, as soon as the packaging is opened, the acrylic binder starts to dry out and lose its usability.

Because the filler in acrylic is so finely ground, it has the advantage of having an exceptionally smooth surface. High-quality finishing has a pricey drawback: a kilogram of ready-made acrylic putty costs at least fifty rubles, while a kilogram of dry (we stress, dry!) gypsum mixture costs ten to fifteen rubles.

Acrylic putty can be universal (used for both interior and exterior finishing) or used for interior work, depending on the presence of functional additives.

Calculation

How much putty is required for finishing per square meter of surface?

Building mixture consumption information is always available on the package or, in the worst situation, on the manufacturer’s website. To calculate the amount of putty required per square meter, let’s use the German company Knauf’s "Fugen" universal gypsum mixture as an example.

The Knauf Company releases the following information: 0.25 kg/m2 of dry gypsum is consumed when filling drywall seams, and 0.8 kg of mixture is used for every millimeter of coating thickness when applying a continuous layer.

Let’s now focus on the local manufacturer and determine how much putty is required to finish a square meter of facade. A mixture on white Portland cement known as "Volma Aquastandard Light" will be the test subject. The Volma company’s official website has the information we require; the stated consumption is 1.8–2 kg/m2.

Using this information, determine how much putty is required for a room with known dimensions:

  1. Calculate the area of ​​​​the walls of the room;
  2. Determine the average thickness of the coating layer. If the walls were plastered along the beacons, it can be taken equal to 2-3 millimeters, if they were leveled with plasterboard – 1 millimeter;

Captain Obvious reminds us to consider the amount of mixture used to seal the screws and seams in the second scenario.

  1. Multiply the area of ​​the walls by the average thickness of the putty layer and by the consumption declared by the manufacturer, and you will get the volume of purchases in kilograms;
  2. To convert it into the number of bags of mixture, divide the result by the weight of one bag (usually 22-30 kg).

Let"s get started

Let us now put the theory into practice by learning how to putty a surface and doing it ourselves.

Tool

What you’ll need to caulk ceilings or walls:

  • A pair of spatulas – wide (30-40 cm) and narrow (10-12 cm). The first is used for the actual puttying, the second is for applying the putty to a wide spatula;

  • When finishing corners, use a corner spatula;
  • When using dry mixes – a wide container for mixing the mixture and a construction mixer or drill with a whisk.

Preparing the base

The required surface for puttying is:

  • Durable (that is, without peeling or crumbling coatings);
  • Clean – free of dust and grease stains. Dust is removed with a vacuum cleaner or brush, oils and fats – by degreasing (with a rag and any organic solvent);
  • Primed with penetrating primer. It will bind dust residues and strengthen the surface.

Mixing the mixture

The precise proportion of mixture to water when mixing is always specified in the manufacturer’s instructions. Avoid mixing putty by eye; a solution that is too thin will flow off the tool and the wall, and a solution that is too thick will lay unevenly.

There is a subtlety when combining gypsum mixtures that should be noted. Gypsum must be added to a container containing water, not the other way around. The gypsum mixture will solidify into nearly insoluble lumps at the bottom of the container if water is added to it.

The putty is mixed, then allowed to sit for three to five minutes before being re-mixed and put to use.

  1. Do not prepare the mixture in large portions. Mix as much as you can use within 30-60 minutes;
  2. Always wash the container and tools after using up the next portion. Otherwise, the seized lumps will fall under the spatula and spoil the finish with untidy grooves.

Application

Using sliding motions, the putty is applied to the wall or ceiling using a narrow spatula applied to a wide one. Applying multiple layers involves applying each one parallel to the one before it. It is preferable to putty in the brightest light possible that is shining at an oblique angle onto the work surface, as the shadows will highlight all of the imperfections.

  • When sealing the seams in plasterboard structures, the first layer is applied directly through the cells of the serpyanka (rolled fiberglass mesh) glued along the seam;
  • To align the external and internal corners, use an angled spatula;
  • If you are using putty to repair cracks in the walls, first widen the cracks with a chisel and hammer;
  • If there are a large number of small cracks in the plaster, putty it over a fiberglass mesh or fiberglass. Reinforcement will prevent cracks from appearing on the surface.

Post-processing

A day after applying gypsum or acrylic putty, the final layer dries, and the surface is sanded using a float or grinder. For the first pass, the author uses sanding mesh #80, and for the second pass, #120. The surface is vacuumed and primed for painting or wallpapering after sanding.

Keep in mind that cement mixtures require a minimum layer thickness of two to three days to dry completely.

In order to achieve even, smooth surfaces for painting or wallpapering, putty is essential. It repairs holes, cracks, and flaws to guarantee a perfect finish that improves the appearance of your walls as a whole.

Putty preparation is simple, but to get the proper consistency, pay close attention to the directions. Whether you use a pre-mixed putty or mix your own powdered putty with water, make sure it is lump-free and has a creamy texture for easy application.

Apply putty in thin layers and build it up gradually to the desired thickness. For a smooth and even application, use a putty knife or trowel, and make sure to let each layer completely dry before applying the next. Sanding in between coats will make the finish flawless.

Putty can significantly improve the quality of your wall surfaces when applied and prepared correctly, laying the groundwork for decorating projects that look professionally finished.

Video on the topic

THE simplest BUT correct METHOD of applying putty

13☼ How to prepare universal putty and how much

DIY CAR PUTTYING! RECOMMENDATIONS for beginners! FIRST EXPERIENCE in car puttying WITHOUT MISTAKES!

What interior style do you like the most?
Share to friends
Veronica Gerasimova

Interior designer, author of books on the design of residential premises. I will help you make your home not only functional, but also beautiful.

Rate author
Vash-Variant.com
Add a comment