Spruce - wood for log houses, but also for violins and guitars

Unlike hardwood, which differs in colour, pore size and arrangement or fibre appearance, and for this reason preferred in the furniture industry, resinous wood is much less particularized, the species being easily confused. However, resinous wood has a wider presence in industry, being used in construction, landscaping, wood-based panels, furniture and paper. Our most widespread species of resinous tree is the spruce, which occupies 22% of the forest cover, i.e. over one million hectares. This is a good argument for studying it more closely and discovering its pluses and minuses.

Widespread in northern, central and eastern Europe

Picea abies (Norway spruce, European spruce or German spruce) is native to northern, central and eastern Europe, reaching as far north as the Arctic Circle and the Ural Mountains are considered the eastern limit. Here it encounters the Siberian spruce (Picea obovata) with which it hybridizes easily. This is why the boundary is for information only, the actual boundary is impossible to determine.

In addition to its natural distribution, spruce is widespread in plantations, both within and outside its natural range, being a species grown for timber and for use as a Christmas tree. It is the second most used species for this purpose after Nordmann fir tree. It grows naturally at altitudes from 500 m to 1700 m, even 2000 m, but in plantations it grows well at 250-300 m. As an ornamental tree it can also grow in lowland areas, but it lives shorter than a mountain tree, which can live 400-500 years. It can be harvested after 80 years, with the most wood being harvested at around 120 years of age.

The spruce is a mountain and subalpine species in our country, being present in almost the entire Carpathian chain. It is the most widespread resinous species, occupying 22% of the forest stock. It prefers a moist and cool climate, is more demanding than fir, but less demanding than spruce. Scots pine, sensitive to drought in the first 2-3 years of life. There are several varieties of spruce that differ in crown shape, branching, trunk or cone color and other such criteria.

Molid, molift or red fir

Molid, molift or red fir are our names for this species. The red fir is named after the slightly reddish color of the bark. The tree commonly reaches 30-40 m in height and 1 m in diameter, but can reach 60 m in height and 2 m in diameter. A characteristic feature of the spruce is trailing rooting, meaning it can cling to shallow soils on cliffs, with its roots only 20-30 cm (8-30 cm) into the soil, making it less wind-resistant. This is why you often see fallen spruce trunks in forests.

The stem is straight and cylindrical, covered with reddish-brown, sometimes grayish bark. The crown is pyramidal and conical even in old age, and the branches are helically arranged around the trunk. Leaves are needles arranged around the branch, persistent, stiff, pointed, dark green. The fruit, green and reddish cones when young, turn brown when mature. The hanging cones, 10-15 cm long, are a differentiation between spruce and fir, whose cones face upwards. The seeds are around 4 mm, brown and have a 12-14 mm wing to help them spread.

Structure and properties

Freshly cut spruce wood has a strong resinous smell and a creamy white color with a slight yellowish tinge. It begins to darken in color soon after cutting, with light accentuating the process and the color turning reddish-brown. There is no difference between sapwood and heartwood, but the annual rings are well distinguishable, the later wood being darker and denser. The transition from early to latewood is gradual. The grain is fine, straight and uniform, with resin canals visible under the microscope. When freshly planed, the wood has a slight sheen.

The average density of spruce varies between 410 and 470 kg/m³, depending on growing conditions. Density is closely related to the width of the annual ring; the narrower the annual ring, the denser the spruce. This is important to know because mechanical properties of wood decrease with density. Good structural wood is considered to be wood with a ring width between 4 and 6 mm. The properties also decrease with increasing moisture content, with the correspondingly dry wood at 8-12% having the best mechanical properties. Durability is medium to low, spruce having low resistance to decay and fungal attack. It has good elasticity, and specimens grown under special conditions have a special resonance and are used in musical instruments.

The molol is easily worked by hand or machine, except in the knot area. The presence of resin may load the knives which will have to be cleaned with white spirit, turpentine or other special thinners. It glues smoothly, but is more difficult to stain because of very low absorption in latewood areas. For this reason it tends to color in reverse, like a photographic negative (light areas become dark and vice versa). Special stains, containing resin that prevents absorption, are recommended for uniform coloration. Large resin pockets can cause problems when finishing, so removing them is recommended. Can be coated with oil, wax, varnishes and paints.

Uses

Spelt is used as timber in general, in the construction of timber-framed houses or log or roundwood houses, or in the construction of roofing. It is used in furniture making and veneer cutting. It is the raw material for making chipboard, MDF or wood panels and laminated beamsand for pulp and paper. It is used in interior design for various furnishings. Resonance wood is used to make classical guitars, violins and violins.

Despite its low resistance to decay, it is also widely used outdoors, for cladding houses, making doors and windows, building pergolas, gazebos and fences. In this case, the wood must be well protected with special materials with good sun and weather resistance or autoclave impregnated with special substances that increase its resistance to water and fungi.

Spruce bark is used to obtain tannin, and various oils are extracted from the bark, such as turpentine balma natural diluent. The buds are used in herbal pharmacy.

Spruce wood can also be used as fuel. It is mostly used to make pellets and lighters, but is also used as a firewood. Not recommended for open fireplaces because the resin causes cracking and sparking.

The Douglas fir is a species that protects slopes from landslides. Its crown has the ability to retain a large amount of water or snow, which then stops it from soaking into the ground and making it unsafe.

I hope you find the information interesting. Complementaries are, as always, welcome. And if you have any questions or queries, please leave them below in the space provided. I will certainly reply.