Facade primer - its types and application

Gusevsky Andrey Anatolyevich

Facade primer will extend the life of walls and exterior

Have you ever seen a relatively new home, from which decorative plaster falls off? Or peeling paint? Or mold spots appear, and moss grows on the bottom?
All this is the result of neglecting such an important stage as preparing the surface for decoration. To avoid this, a simple and relatively inexpensive tool will help - a primer for the facade.

Types of facade primers

Primers in construction are used everywhere, both in rough and when finishingboth outside and inside buildings. Their main task is to ensure a reliable connection of materials with each other.
It does not matter what it is about: the device of the bulk floor, plastering, painting or sticker wallpaper. In order for each subsequent layer to be of high quality and hold well, the previous in most cases needs to be primed.
Perform these building mixtures and other important functions. What exactly should primers for a building facade have?

Destination

Since the facades of buildings are subject to constant influence of the atmosphere, the main thing that their primer should protect from is moisture. Even if the house is sheathed with siding or other material that is not susceptible to a humid environment, the main walls will suffer from it even under the sheathing.
That is why all facade primers must have water-repellent properties.

Note. This is a mandatory property for facade soil. If the product you have chosen does not possess it, it is not recommended to use it for outdoor work.

The presence of other properties is selected depending on the type of surface to be treated.
Take, for example, the following options:

• For wooden substrates, it is necessary to use compounds with fungicidal and antiseptic additives to protect them from fungi and insect pests (seePrimer wood - process features);
• For concrete and brick walls, under primers, primers are used to ensure good adhesion of materials. They should reduce the absorbent properties of the base and roughen it for better adhesion to the solution;
• A deep penetrating front primer will strengthen loose and crumbling substrates. Penetrating into their pores and cracks to a great depth, it polymerizes, hardens and thereby binds all particles of the material;

The principle of the deep penetration primer

• Primers with anti-corrosion additives are designed to protect metal surfaces. It is unlikely that they are in demand in individual housing construction, but utility buildings, sheathed with sheet metal, will last you longer after such treatment.

Structure

The properties of primer mixtures depend on their composition.
They are classified according to the base material:

• The basis of mineral soils are cement, lime or gypsum. Due to the rather thick consistency, they are able to smooth out small irregularities. They are used for processing walls made of bricks, expanded clay concrete and gas-silicate blocks, reinforced concrete panels.

Attention! The mineral primer is selected depending on the type of surface to be treated: for gypsum - based on gypsum, etc. Concrete substrates are allowed to be primed with any mineral composition.

You can apply such a primer with a brush or roller, or with a wide spatula

• Acrylic primers, as the name implies, are made on the basis of acrylic polymers. They are universal, suitable for any basis.
  Their main advantages are low price, ease of application, short drying time, the ability to dilute the mixture with water to the desired consistency.

Smooth surfaces for plastering are best treated with a primer with quartz sand, giving it a roughness

• Primers based on alkyd synthetic polymers are used only for wooden and metal substrates, they are categorically not suitable for gypsum or plaster. They are an ideal base for painting or ceramic tile lining.
  If the tree is not supposed to be finished somehow, it can be given the desired color using a tinted composition.

The wooden structures of the open terrace in the photo are covered with a tinted alkyd primer.

• On the basis of polyurethane, universal two-component primers suitable for different surfaces (including wet) are made. They have unique adhesive and strengthening properties, dry quickly, they are easy to work with, but they are quite expensive.

As you can see, you have plenty to choose from. It is difficult to make a mistake in choosing the right composition: the package always has instructions indicating the area and conditions of use, consumption per square meter and other useful information.

How to prime the facades

The production technology itself is simple, the video below will help to study it. But it will not be superfluous to remember several basic rules that must be followed necessarily.
So:

• The foundation before work must be carefully prepared. Preparation consists in mechanical cleaning of the surface from exfoliating particles, dirt and dust, removing oil stains;

Attention! Oil stains must always be degreased with gasoline, white spirit or other solvents. Otherwise, the coating in these areas will not hold, and will begin to fall off almost immediately after application.

• The walls prepared for processing must be dry. Only a mineral and two-component polymer primer may be applied to a slightly damp surface;
• Apply the mortar to the facade in strict accordance with the manufacturer's instructions. Some concentrated formulations require prior dilution with water or a solvent.
  For example, a facade deep penetration primer for applying the first layer is often made as fluid as possible so that the solution penetrates all microcracks and pores, and subsequent layers are applied undiluted;

The solution can be applied both manually and with a spray.

• The drying time specified in the instructions is not an empty sound, it must be maintained, not allowing the application of the following primer or finish layers ahead of time.

If you have chosen the “right” primer and strictly followed the technology when applying it, you can be sure that the walls of your house will not “bloom”, will not get wet and collapse under the influence of external factors, and the decorative finish will stay on them for a long time and reliably.

Conclusion

The information provided in the article is useful not only for those who are going to finish the facade with their own hands. This knowledge will help to competently control the contractors who undertook such work.
The primer is an intermediate stage that is invisible after final finishing. It can be included in the estimate and presented for payment, but in fact not be implemented. Be careful.