- Main functions of paintwork
- Special properties
- How to choose a paint base
- Color, gloss and transparency
- Consumption and application methods
It so happened that the first available paintwork materials are chosen to cover wooden facades, while paints for wood have completely different properties. Today we will tell you how to make the right choice of paint or varnish when it comes to the exterior of a wooden house.
Main functions of paintwork
Why paint a tree at all? The answer, at first glance, is quite obvious: to extend the life of the wood, to provide it with additional protection. This is really the main, but not the only function of paints and varnishes for wood, in addition, you need to understand what factors of harmful effects the coating will have to deal with.
The most important indicator for any facade paint is weather resistance. It is about the ability of the coating to resist moisture absorption and maintain its integrity under the influence of chemically aggressive substances dissolved in rainwater. Resistance to sunlight is also important: transparent compounds that preserve the wood texture should contain a UV filter to prevent darkening of the wood, and opaque ones – just keep the color of the coating as long as possible.
The paint or varnish should also promote aseptic properties. As a rule, this is achieved by protecting the wood from getting wet, however, many paintwork materials have additional additives that prevent the development of destructive microflora. Do not forget about pests: high-quality paint covers the wood with a hard shell, which the bark beetle cannot gnaw through.
Finally, decorative properties should not be overlooked. The facade is the face of the building and the entire exterior depends on its appearance. Depth and correct color matching in accordance with the details of the surrounding landscape will provide aesthetic harmony and make the home pleasantly stand out from the surrounding background.
Paints can exhibit different performance characteristics depending on climate and a variety of other environmental conditions. They are mainly determined by the technical properties of the coating and depend on the chemical composition of the paintwork materials.
For different regions, you should choose a paint with a certain degree of frost resistance. The material must retain a certain amount of elasticity at low temperatures so that the coating does not crack. No less important is the ability to withstand high temperatures without irreversible changes in the structure of the coating, because on a hot day, the wall of a building illuminated by the sun can heat up to 70 ° C.
You also need to remember about the ability of the paint to reliably adhere to the base. Most materials, even from a low price category, have good adhesion to clean wood, but the situation changes radically if the wood is already coated with some kind of compound. To avoid the exhausting process of cleaning the facade, you should choose the right composition so that the base of the paint or varnish does not conflict with the existing coating.
The ability of paint to withstand mechanical stress should not be overlooked. It seems that this indicator is not important for the facade, however, the dust contained in the air works as an abrasive and gradually thinns the upper glossy layer, due to which the coating loses its resistance to moisture, sunlight and biological erosion over time..
How to choose a paint base
Almost all paints and varnishes consist of a base, a solvent and a coloring pigment with a set of additives. And if the appearance and some special properties depend on the last components, then the main characteristics of the paint are determined precisely by the base, which can be of three types.
Water-soluble acrylic paints are the lightest type of coatings, they are not able to withstand the destructive effects of the natural environment for a long time. Therefore, they are usually used with the expectation of regular renewal, or if the wood itself is stabilized and does not need protection. The advantage of acrylic paints is ease of application and environmental friendliness, as well as the ability to easily form an individual shade on your own.
Paints based on synthetic resins – glyphthalic, pentaphthalic and others – are called alkyd enamels. Their main difference is that they create a durable glossy film on the coating surface, which, unlike a film of acrylic paints, is an impenetrable barrier: it does not allow water to pass through and limits the coating base from a chemical reaction with atmospheric gases. Not all alkyd enamels are highly weather resistant, but this type of paint provides the highest degree of wood protection. Often this group includes polymer-based varnishes and paints, but not because of chemical relationship, but because of the similarity of performance.
The third type of base includes stains, which are designed to give the wood a certain color and act as an impregnation that protects against bacteriological damage. Stains do not form a film, and therefore are not able to protect wood from getting wet and aggressive chemical attack. For this reason, they are used only under the condition of subsequent opening with varnish, as a rule, transparent.
Color, gloss and transparency
The choice of paintwork materials for finishing wooden facades, as a rule, is carried out in order to give the building an exceptional appearance. The success of the solution largely depends on understanding the basic principles of working with wood, as well as on your own taste..
Paints of bright saturated colors are very rarely suitable for the facade. On the contrary, the most advantageous will be the choice of a calm natural color. If the house is located in dense buildings, it is better to give preference to soft pastel colors. For houses located near bodies of water, variations of blue and green are well suited, but always muted with gray..
Buildings located in a natural environment, for example, with a high density of green spaces, are usually trying to highlight, painting in colors from sulfur and mustard to dark brown. If natural stone appears in abundance on the adjacent landscape, red-brown tones are well suited, as well as deep green and almost all light shades..
The paint does not have to have a high pigmentation density. Some enamels allow for partial manifestation of texture, which is very good for houses whose façades are finished with high-quality sawn timber with a minimum amount of blemishes. If the emphasis is on the natural naturalness of the building, it is better to give preference to tinted and transparent varnishes. It should be remembered that the more transparent the coating is used, the more high-quality the wood should be and the more thorough its processing should be carried out before varnishing..
All facade paints differ in the degree of gloss, which must be chosen taking into account two circumstances. The first is the norm of natural light: shinier coatings look better in shade, while a house with matte paint will not glare too much in direct sunlight. It should also be borne in mind that the higher the degree of gloss, the smoother the film is created on the surface during drying, which means that the protective properties of the coating will be higher..
Consumption and application methods
Paints and varnishes differ significantly in viscosity and hiding power, which limits the choice of the method of their application. For example, the so-called film-forming impregnations can only be applied with a brush, which is extremely inconvenient when finishing surfaces with a large area or when working at height..
Alkyd enamels and varnishes in this regard are the most versatile; when working with them, it is allowed to use a roller or a spray gun. Acceptable application methods are indicated by the appropriate pictograms on the label. When covering wooden facades, it is optimal to work with a roller: paintwork materials that allow this method of application, significantly increase the speed of work without increasing consumption.
The total amount of paint for finishing the facade is determined by the consumption rates declared by the manufacturer, the surface area and the number of layers. It is imperative to take into account that the consumption when painting rough and smooth surfaces can differ by 1.5–2 times. Also, when using a spray gun, it is necessary to purchase paintwork materials with a margin of about 20-25%. The speed of drying of the paint before applying the next layer and the permissible temperature regime are of no small importance – these parameters must be taken into account when planning painting work.
The nomenclature of modern paints and varnishes is organized in such a way that for each individual product a specific chemical composition and any quantitative expression of the main properties are not indicated. This is done not only to keep a trade secret, but also to make it easier for the buyer to choose..
Therefore, when buying paint for your wooden facade, the most correct approach will be to be guided by general ideas about the behavior of a particular type of paint, as well as assign the responsibility for the selection of paintwork materials to consultants. In this case, you only need to indicate the type of surface and type of wood, the presence or absence of any coating, the region, special operating conditions, the desired service life and additional wishes.
Please note that not only paints are used to protect wooden surfaces. The manufacturer will definitely recommend a suitable primer and protective impregnation. If high requirements are imposed on the facade in terms of durability and quality of appearance, such recommendations should not be neglected..