Primer of drywall before puttying: is it necessary and how to apply it correctly

One of the popular questions among finishers is whether it is necessary to prime drywall before puttying. Often they answer positively, citing the fact that pre-treatment improves the adhesion of the base. To some extent this is true, but drywall has its own characteristics. Therefore, it is important to understand in which cases preparation is needed and in which it is not. This and much more is discussed in the material presented.

Do I need a primer?

The question of whether it is necessary to prime drywall before puttying does not have a clear answer. On the one hand, experienced finishers often respond positively to it, because the primer prepares the surface well and increases adhesion with the subsequent material.

When studying whether drywall needs to be primed, it should also be mentioned that the preparation disinfects the surface and protects it from rotting. In addition, the primer levels out minor irregularities, although the sheets are usually smooth and do not need such treatment.

But if we look at what a drywall primer does under putty, we need to understand in more detail how such a composition works. It penetrates deeply into the surface (paper) layer of cardboard and spreads further. As a result, the pores become clogged and dust particles stick together on the surface.Accordingly, adhesion decreases, and the putty adheres worse than on an untreated surface. In this case, the answer to the question of whether drywall can be primed is negative.

Thus, primer on drywall gives 2 opposite effects:

1. It clogs pores, which leads to poor adhesion to the putty.
2. It binds dust, which, on the contrary, is good, because dirt particles interfere with further finishing.

In this regard, doubts arise whether it is necessary to prime drywall before puttingty. It is worth recognizing that there is no ideal solution. Processing has its pros and cons. Therefore, you need to navigate the situation:

1. If there is little dust and it is possible to remove it, for example, with a damp sponge, it is better not to take additional measures.
2. If the surface is heavily contaminated, and it is difficult to remove dust from it, the benefit of the primer is obvious, and this step cannot be avoided.

Pros and cons of priming

Regardless of how to prime drywall before puttying, you can take into account the manufacturers' recommendations. Thus, the instructions for Knauf mixtures indicate that the edges of the sheets must be primed, i.e. edges where a lot of dust inevitably accumulates. After treatment, the composition should dry for 3-4 hours.

This method of preparation provides several advantages that allow you to have no doubt about whether it is necessary to prime drywall:

• protection against mold, rot;
• the ability to choose the appropriate color;
• protection from damage;
• environmentally friendly composition;
• affordable price;
• simple application technology - methods for priming drywall before puttying are available to everyone.

Although there are also disadvantages:

• the grip is not always strong enough;
• the composition fills the pores of plasterboard sheets and reduces adhesion;
• may lie unevenly - then there will be smudges on the surface.

Types of primer

Now it’s clear whether drywall is primed before puttying. In most cases, yes, because it gets rid of dust and prepares the surface well. Therefore, it is important to understand how to choose the right composition specifically for drywall. Most often used for processing:

1. Universal acrylic mixtures that dry in literally 2-3 hours. Affordable, suitable for exterior and interior use, non-toxic, available in a wide range.
2. Primer of drywall before applying alkyd putty is a very common type and is used on various surfaces.
3. Polyvinyl acetate (PVA) - based on glue of the same name. You can do it yourself or purchase a ready-made composition.

Other types are of little use. For example, you cannot prime gypsum board before puttying with phenolic or polystyrene compounds. They are toxic and give off an unpleasant odor and are suitable only for outdoor use.

There is another classification depending on the properties of the primer:

1. Deep penetration - not suitable for drywall, because it clogs the pores and interferes with adhesion to the putty.
2. Adhesive - increases adhesion on the surface, a universal option that can be used for plasterboard sheets.
3. Composition with water-repellent properties.
4. Fire-resistant primer - especially important for rooms with sources of open fire.
5. Antiseptic – prevents mold and rotting. Suitable for rooms with a humid microclimate, such as a kitchen.

Step-by-step instruction

Thus, it is necessary to prime the drywall before puttingtying. It remains to understand exactly how to do this.First you need to prepare the tools - this can be a brush or roller, as well as a container (bucket). You should proceed like this:

1. Dilute the composition with water strictly according to the instructions.
2. Mix thoroughly and dip the roller or brush.
3. It is clear whether drywall needs to be primed before plaster or putty. First, apply the first layer.
4. After it has completely dried, a second layer is applied.
5. The main way to apply primer to drywall is with a roller. Moreover, you need to strive to ensure that the layer is as thin as possible.
6. When the second layer has dried, they begin to putty.

From this article it is clear whether it is necessary to prime drywall before puttying. They act according to the situation - if the volume of work is large and the room is very dusty, pre-treatment is required. If it is possible to remove dust, for example, with a napkin, it is better to do just that, without priming.