Wood grades: features, types, GOST, application

The modern range of wood materials is characterized by an extensive choice, which often makes it difficult to determine the quality. Despite the fact that the main information and characteristics are displayed in the accompanying documentation, do not forget about the recommendations of professionals involved in the sale of wood. Before buying, it is necessary to familiarize yourself with the possible defects that directly affect the cost and properties of the material, as well as with the processing methods and structural features that wood has. Varieties, breeds, as well as growing conditions are key aspects of choosing a quality material and the best option for its use.

Features

Lumber, as well as any other materials for construction, are classified by grade. This parameter depends on the quality of the wood processing and its characteristics. To determine the type of special tool is required, so this is often done by professionals. In any case, it is necessary to pay special attention to the appearance of the purchased goods to determine the quality and purpose.

Wood: grade 1

Varieties are designated by numbers from one to five. The exception is the selected grade of wood, GOST Which has a more rigid framework regarding the quality of this material. It is used in shipbuilding and has not the slightest defect.

On first-grade blanks, traces of small cracks, knots and splits may be present. In this case, there should be no dark spots, traces of parasites, putrefaction, fungus and mold. As an example, you can use an edging board - it should be dry, without dead particles, longitudinal through slits and noticeable damages. There should be no core, roll, and the total slope of the fibers may be within 5%. Such products are distinguished by their lack of flaws and attractive appearance. They are used in finishing, exterior, interior work and the erection of load-bearing elements.

Wood: grade 2

This material, unlike the first one, can have a large number of flaws. It may contain cracks with a length not more than a third of the total product. At the same time, the parameters of their width and depth remain at the same level. Perhaps the presence of one large trace of parasites or a few small ones. The first and second grades of wood have minimal differences, so the latter variant has become most widespread in outdoor works.

Grades 3, 4, 5

The third grade of lumber is intended for flooring, plating and carries small loads. It can contain virtually all types of defects, including traces of wormholes, rot, dark spots and mold. Perhaps the presence of deep cracks with a length of not more than the entire length of the product.

The fourth grade is used for sawing small preforms, erecting elements under minimal load, as well as for packaging and packaging. The main requirement of GOST is the integrity of the elements, and any defects in the surface and in the whole structure may be present.

The fifth grade is of the lowest quality. It is not intended for plating, furniture and other work. Used most often for lighting fireplaces and stoves.

All species have a different value and are used in certain areas of activity. Knowing the type of wood, you can not only pick up the right material with the necessary characteristics, but also save the budget, because in some cases they can replace each other.

Needles

Wood differs resinous, astringent odor and a clearer structure. The most widely spread cedar, fir and pine, they are used both in the production of various items, and in the construction of houses and other objects. The leading place is occupied by pine, it can have a different shade, which does not depend on the quality of processing.

Among the advantages are the lightness, strength, resistance to negative atmospheric influences and rotting processes due to the large content of resins. It has a loose structure, which provides a high adhesion to paintwork materials.

Spruce is in second place in popularity. It does not have such an extensive list of advantages, like pine, is more difficult to process due to the denser structure and a number of knots. Due to the minimum tar content, spruce products have an average degree of resistance to precipitation and rot.

Kinds of wood of coniferous breeds are classified as well as deciduous, specifications of their quality are defined in GOST 24454-80. It is worth noting that, in addition to numerical designation, you can often find a marking in the form of letters from A to E. This must be taken into account when buying material so as not to make a mistake with the choice.

Hardwoods

Products obtained from deciduous trees are the most widespread and minimal, almost imperceptible odor, which becomes noticeable only during processing and cutting. Solid wood varieties (such as oak, ash and birch) are indispensable in the manufacture of furniture and flooring. Each of them has its own characteristics. For example, oak has high strength properties and resistance to decay. Solid structure allows you to create on the surface of the finest patterns, use to create fasteners and curved elements.

Aspen, linden and alder belong to soft varieties of wood. This variety is common in construction and is produced in the form of profiles, lining, logs and timber. Softwood has a lower density than the wooden counterpart and must be treated with special protective compounds to prevent decay.

Defects

Defects are the traces of mechanical damage that occurred during processing and transportation. The slope of the fibers often appears after separation from the longitudinal axis. Next to knots, there is often a curvature, which can be through, which causes the quality of the material to deteriorate.

The quality of wood affects not only the breed, but also the conditions of growth (temperature, humidity). Material of one kind, cut down in different regions, can have slight differences in hardness. This parameter is measured on a special scale, for the starting point in which the hardness of the oak is taken.

The strength of the products reflects the resistance to mechanical damage and varies depending on the presence of defects, moisture and rock. Below the ultimate strength is meant a stress, leading to a disruption in the integrity of the material.

How to choose

It is recommended that you inspect the materials yourself before purchasing. Remote order is only available from reputable suppliers. Before you go to the warehouse, you should take a plane with which you can quickly clean the contaminated areas to check the quality of layers and colors.

Of particular importance is inspection for the presence of fibers, uneven layers, knots and cracks. The quality and possibility of further use is affected by the drying of wood. With an illiterate design, cracking, breaking geometry and resizing can occur.

What you need to pay attention to

Most softwood softwood varieties are available - pine, fir, spruce and others. As a rule, this material is realized in the form of elements with standard dimensions. One or more surfaces can be processed. This must be taken into account, since after planing the dimensions of the parts are reduced by a few millimeters, and the actual parameters will be different from those specified by the sellers.

Sorting softwood is made by the presence of minimal defects (small cracks, knots) and the uniformity of the layers. This classification is suitable for the selection of lining and other finishing materials. For the manufacture of furniture and carpentry, quality options are required with an impeccable appearance. High strength is necessary for the formation of structures, materials suitable for this purpose are not usually found in the construction markets, as they are made to order.

Before buying, you need to verify the availability of certificates and product documentation. It should be noted that not all types of timber are required to pass mandatory certification, but most manufacturers are trying to make out in due form all the products sold.