Preventive wood treatment before painting.

Wood is an excellent material for construction, but, at the same time, an ideal material for the life and reproduction of fungus and mold under certain conditions and external factors. Fungus and mold are one of the most, if not the strongest and most common, wood destroyers. Even moisture and sun do not destroy wood as fungus and mold do. The reason is that wood is a porous material in its structure, consisting of cellulose - an excellent nutrient medium for microorganisms and insects.

Therefore, one of the actions aimed at protecting wood is actions to prevent the reproduction of fungus and mold. Such actions include, first of all, treating wood with antiseptics, which prevent both the appearance and reproduction of fungus and mold. But a very important, especially in wooden construction, is the preventive treatment of the surface from spores of fungus, mold, as well as traces of their vital activity - blueness. This is exactly what will be discussed in this article.

The first thing to start with is to define the basic concepts. Wood goes through several main stages of processing before becoming a lining, timber, board, namely felling the forest, sawing into blanks and drying. Wood harvesting according to the norms should be carried out in winter, because in winter there is a suspension of all metabolic processes in the tree trunk, which are tied to the flow of sap (a kind of tree blood). Winter wood, in this regard, has lower humidity and resinous parameters. Nowadays this is not always done, but nevertheless... Then the wood is sawn and dried in special dryers. At all these stages, wood becomes open for mold spores to stick to its surface.

That is why, at all stages prior to the manufacture of the product, it must undergo antiseptic treatment with so-called transport antiseptics. Directly after all stages of fitting parts, assembly, etc. The final processing step is wood painting. To be suitable for painting, it must have the required moisture parameters. For wood used indoors, this parameter should not be higher than 10-11%, for wood outdoors - no higher than 20-22%.

It is worth remembering that at all stages of processing prior to painting, wood is susceptible to fungus and mold spores that fly in the air. Once on the surface, even pre-dried well, spores begin reproducing, thereby triggering the reverse process - starting to accumulate water necessary for fungus nourishment. Furthermore causing destruction of wood respectively. This translates further into cracking, peeling of paint coating on the surface due to the fact that the film of varnish, paint, etc. at a certain moment cannot contain moisture that accumulates inside the wood and tends to leave the wood when heated.

As an analogy, one can draw a sunrise, during which heating of the walls of a wooden house facade occurs and moisture contained in the wood structure begins to evaporate from it. When this parameter is within normal limits, nothing terrible happens. But when wood is infected with fungus, wood moisture increases significantly, because fungus accumulates moisture, and paint coating begins to quickly deteriorate.

This is exactly why prior to painting it is necessary to carry out preliminary preventive washing of wooden surfaces with special means. Mostly this applies to surfaces that will be subject to atmospheric influences, i.e. will not be located indoors. As a rule, these are facades of wooden houses, gazebos, garden furniture, etc. Treatment of their surfaces will give a large reduction in spores of fungus and mold that have somehow got onto wood, respectively, a product made of wood will last many times longer, and paint coating on its surface will be more durable.

The main means for preventive treatment against fungus and mold spores are sodium hypochlorite-based products or simply "bleach" or "chlorine". This component is the main one in all products for the preventive treatment of wood before painting. This component is chemically very active and perfectly kills fungus spores and penetrates deeply into the surface.

The order of their application is very simple: apply the product using a brush, sponge, etc., and then rinse off the product using a large amount of water and leave the surface to dry for 12-24 hours.

Therefore, the order is only this and no other: application, washing off after 1-6 hours, depending on the degree of damage to the wood, drying for 12-24 hours and only then painting. Before application, it is necessary to assess the appearance of the wood. If wood does not have visible signs of damage, color changes, wood washing can be limited to 1 hour, no more. If wood has visible signs of damage, color change, as a rule, this is so-called blueness, which may be a change in wood color as a result of fungus or mold damage, time spent on the surface of wood by a preventive agent must be increased to several hours to be safe and kill all spores, which in large quantities may be contained in wood.

Often, to hide visible defects of wood, especially this concerns the sphere of production of furniture, doors, windows, in the form of blueness, masters or manufacturers bleach wood to give it freshness and pristineness. Bleaching is also used in wood restoration, when it, being outside without protective paint coating, as a result of exposure to UV radiation, acquires a gray color. Concentrated bleaches cope with this task perfectly. Within minutes or hours, wood acquires its pristine color and at first glance is suitable for further painting. But the result, in fact, is very deceptive.

And all because with a large amount of chlorine in the bleach, it simply destroys the wood structure, namely cellulose. And as you know, value of wood is in its unique structure, which is provided by binding of lignin and cellulose. In a way, this is reinforcement and concrete. Destroying cellulose, its strong bond with lignin is lost, and wood becomes a kind of dead, loose, unable to resist external factors. To top it all off, paint coating loses its durability and after a short time will begin to lag.

Therefore, unequivocal answer: minimize the use of bleach and be sure to rinse it off with clean water completely after a few hours! As for old wood, grayed and "deadened" as a result of exposure to environmental factors and ultraviolet light, the use of bleach is absolutely useless. Wood in a month or two will acquire a gray color. The only way out of this situation can only be sanding off top "dead" layer of wood. And no other way.

Wood, first of all, of course located outside buildings, as well as indoors in humid rooms such as steam rooms, saunas, bathrooms, kitchens, is constantly exposed to strong impact of moisture on it, which, as has already been established, is favorable environment for reproduction of fungus and mold, which destroy it, and indoors they also pose harm to human health, who breathes flying spores in air. Therefore, it is recommended to perform preventive wood washing with wood cleaning agents at least once every six months. This especially applies to wood on the facade. It is constantly susceptible to spores of fungus and mold sticking to its surface, which fly freely in the surrounding air.

Facades must be washed with weak solution of detergent, applying it to surface using sprayer. Places where fungus spores still managed to catch onto wood surface and pass through paint coating must be sanded off in time, washed with detergent and painted over. Thus, paint coating has every chance to stand for seven, or even ten years, protecting wood and performing its decorative properties.

As for rooms inside, first of all, the key to the absence of fungus and mold on the walls is optimal humidity, which in turn is achieved by creating proper ventilation inside. About caring for wooden walls, in particular in steam rooms and bathrooms, there is a separate article on our website.