Many parts of a building are loadbearing, for example floor beams, roof trusses and certain parts of timber framed walls. It is often necessary to calculate the loads involved and then choose a dimension which can carry these loads.

In relation to its weight, timber is a strong material and it is therefore frequently used in loadbearing constructions. The timber for these purposes is called construction timber, and it is stress-graded – either by machine or visually – on the basis of various stress-grading rules.

The table below illustrates the dimensions of timber our  sawmills normally produce for different areas of use - construction, building and joinery, and for other purposes. The table also illustrates the most common cross-sectional dimensions of both planed timber (planed on all four sides) and timber with one fine sawn face (re-sawn surface) for different areas of use.

The cross-sectional dimensions are given in mm (thickness x width), and apply at a target moisture content of 18% for sawn timber and 16% for planed timber. Other dimensions are however also available, since our sawmills can adapt our production to both the international and Ukrainian  markets.

Our timber is a valuable material and therefore it should be handled with care, to avoid damage. Timber should be handled properly in transit, in joinery factories and on building sites in order to achieve the best possible final results.

Timber can be stored outdoors provided that it is protected from rain and snow, from the sun, and from dirt and ground damp. Timber intended for visible indoor use, for example paneling, flooring, pre-manufactured joinery and fitments, should, when necessary, be stored in heated and ventilated indoor premises.

Our company sawmills deliver sawn timber according to the qualities and sizes specific markets demand. For the European market, the European EN standard and the Ukraian publication SS-EN 1611-1 Sawn timber – Appearance grading of softwoods – European spruces, firs, pines, Douglas fir and larches are typically applicable. The EN standards are developed by the European Committee for Standardization, CEN.

For other markets, specific standards are developed. Sawn timber with qualities, strength grades, sizes and moisture contents not described in the European EN Standards and the Nordic Timber Grading rules is usually intended for overseas markets. Swedish sawmills have the capacity to produce and export large quantities of timber that complies with Japanese, American and Chinese national standards. The Chinese national product standard for European structural timber is one such example.

IMPORTANT EN STANDARDS FOR STRENGTH-GRADED TIMBER AND SAWN TIMBER

Strength-graded timber
• EN 336 Structural timber – Sizes, permitted deviations
• EN 338 Structural timber – Strength classes
• EN 384 Timber structures – Determination of characteristic values of mechanical properties and density
• EN 408 Timber structures – Structural timber and glued laminated timber – Determination of some physical and mechanical properties
• EN 1912 Structural timber – Strength classes – Assignment of visual grades and species
• EN 14081-1 Timber structures – Strength-graded structural timber with rectangular cross section – Part 1: General requirements.

Sawn timber
• EN 1309 -1 Round and sawn timber – Method of measurement of dimensions – Part 1: Sawn timber
• EN 1313-1 Round and sawn timber – Permitted deviation and preferred sizes – Part 1: Softwood sawn timber
• EN 1611-1 Sawn timber – Appearance grading of softwoods – Part 1: European spruces, firs, pines, Douglas fir and larches
• EN 14298 Sawn timber – Assessment of drying quality

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Sawmill Industry

Our Company Wood meets Arabia

Wood processing and finishing technologies often require the use of chemicals, such as adhesives, paints and coatings, as well as impregnation or pressure treatment to improve wood’s (biological) long-term durability (fungi and insects/termites) and moisture resistance. The application of wood preservatives is made under very strict control in closed systems and conforms to the relevant national regulations.

Pressure-treated timber for construction, agriculture, landscaping, marine, railway and garden products, and many other applications, enjoys an extended service life and provides a good alternative to non-renewable materials.

The illustration above shows different treatments for different applications. NTR/M wood is intended for permanent contact with sea water, such as piers and harbour installations.

NTR/A is intended for wood in permanent contact with ground or fresh water, or in above ground constructions where personal safety demands that it does not weaken, or in situations where it is difficult to inspect or replace. Applications of class NTR/A treated wood include posts, balconies, garden wood and freshwater constructions (docks, etc.).

NTR/AB is intended for wood that is exposed to weather and wind or condensation, but is not in contact with ground or water, and where replacement of damaged sections and personal safety are not the foremost concerns. Applications of class NTR/AB treated wood include fences, planking, trellises, pergolas, deck/patio flooring and playground equipment.

NTR/B is only for external joinery above ground, such as windows and doors, given a surface protection by painting.

NTR (Nordiska Träskyddsrådet) is the Nordic Wood Protection Council. NTR has developed the Nordic classes and requirements for preservative treated wood, and the strict rules for factory production control and third party control of the treated wood.