”Historically, log construction has its roots in Scandinavia. Although their origin is uncertain, the first log structures were probably being built in Northern Europe by the Bronze Age (about 3500 BC).
C. A. Weslager
Genuine Northern Wood
The Finns are known for their modest wood retreats usually situated on one of their many lakes. Finn wood is an excellent material for building residential homes, leisure houses and summer cottages. This wood is energy efficient, natural insulator and is very effective in coating building façade against outer cold and heat. This material brings about significant amount of energy saving when compared to stone, concrete and brick houses. Finish wood material is also an extraordinary noise absorber, making wooden houses warm, relaxing and peaceful. In addition, it is economically efficient because of simple joints and its ready and quick construction process when compared to masonary buildings made from materials such as stone or concrete.
From architectural perspective, it is a versatile building material. Light load contributes in portability and detachability of structural components. Making additions, changing the plot sizes or moving around rooms within the design are all feasible alternations allowing architects to design flexible layouts. Whether it’s a conventional plot or modern residential, the change could possibly cause the space to grow as mixed-used rooms. From sustainability approach, Finish wood is environmentally friendly. It is fabricated from the sustainable, renewable timber of forests in northern Finland and produced without the use of fossil fuels. These products, thus, are not only environmentally friendly with regards to their origin, but what they accomplish when built: wooden structures actively help the environment by absorbing and storing atmospheric CO2.
Finn Raw Material
Finn raw material is machined from polar Pine, a type of pine that grows in the northern latitudes, and its quality is determined by slow growth which is best described by the harsh climatic condition and ideal soil type. The raw material comes from the well-managed, sustainable forests in northern Finland extending on both sides of the Arctic Circle. Main features of such wood include: Small knots, very tight ring formation, high tensile strength and low moisture. The harsh climate of Northern Finland forces the trees to mature slowly, the short growing season produces a dense, even structure where the resin flows in narrow ducts. The conditions give the wood an ideal protection, a strong resistance and durability. This wood has unique structural properties with low moisture content. Log thickness varies according to the taste and climate. Facts assured that a Finnish wood will withstand even the most harsh weather conditions.
The polar pine tree, as the main material, grows very slowly in Finland Lapland. Lapland is one of the world’s cleanest areas, and the wood reach out the maximum durability during growth to be ecological and renewable building option. Polar pine is stronger than southern pine.
The tensile strength, which is measured by pulling the wood fiber from the opposite direction, reduces the wood material’s susceptibility to cracking and improves joint durability, and is much greater with the polar pine than its southern counterpart. Also, the surface hardness of the polar pine in relation to the density of the timber is greater than that of the southern pine.
There are also other factors that affect wood density. Even though wood density is small in the north, the lumber made from polar pine is stronger than its southern counterpart because of its straight wood fiber and smaller branches. Extra strong varieties are also available, more so than with any other types of coniferous trees.
Advantages of Polar Pine
Some outstanding qualifications that make the Finn wood genuine choice for construction include:
The growth in length and diameter are significantly slow and the branches remain small. As for the use of wood material, this can be seen in low priced thin growth rings, making the wood is less prone to tears and cracks when worked. Also, the amount of young wood that is harmful to workability is sparse compared to most coniferous tree types and the southern pine. The width of the polar pine’s growth rings changes less from the core to the surface than that of the southern pine
Also, the density of the wood material changes less within a single trunk than in the Southern pine.
The density directly affects other qualities, such as strength, so the polar pine’s wood material is in many respects more of uniform quality than the southern pine. The gluing and finishing (paint, varnish, wax) of the polar pine is easy as long as the pieces do not have extra parts or resin.
The gluing is durable and the finishing guarantees an even surface.
Beautiful and strong heartwood
Due to slow thickness growth, same sized pine trunks in the north have more growth rings than in the south. When they reach a certain width, the polar pines are older and have relatively more heartwood which provides many spectacular qualities. Heartwood is generally darker and more saturated than sapwood. In the north, the difference in color between heartwood and sapwood is at first quite big, but over time it evens out as the color of the wood gets darker, mainly because of UV – radiation. The even coloring of the wood material, from aseptically, gives the logs brighter and more modern surfaces. With larger surfaces, a balanced appearance is also obtained by the smaller size, roundness and even positioning of the branches.
The advantage of polar pine is that as it grows slowly for a coniferous tree, not much juvenile wood is produced; the juvenile wood close to the core has qualities that are in many ways inferior to other wood material. The large portion of heartwood is a positive attribute, due to a smaller rate of moisture absorption. Units manufactured from heartwood change less in size as a result of air moisture change than those manufactured from surface wood.
Sturdy wood: great bending strength, compression strength, cutting strength and tensile strength Light but durable: very light and strong compared to its weight
Even strength division: narrow growth rings and little variation, little juvenile wood
Less cracking: large tensile strength when pulling the wood fiber from the opposite direction
Log Production Technology
Finland benefits from the latest manufacturing technologies, which enable obtaining highly precise milling and efficient production. Strict quality control guarantees perfect result and full customer satisfaction. Finish log houses are the very best from Finland fore.
After sawing, wood is dried in computer guided drying chambers in order to get optimal moisture rate before laminating. Next, wood goes through quality control to detect any faults or defects. Perfect parts are selected to make logs and are laminated in two ways: hydraulic press by using ultra-resistant glue, which conserves wood fibers natural filtering capacity, and unique Rotoles technique, which is a special method to open the cell tissue in the planning phase. This way, the glue goes deep into the cell tissue of the wood and the glue joints of the logs and beams become tight and secure. The result is a high-quality laminated log with glue joints that do not crack open. Sample pieces of each lamination series is tested, which is exposed to high-pressure in chamber to verify perfect gluing result. All traditional materials, such as round log as well as modern laminated squared logs, laminated round logs and highly durable cross-laminated logs are fabricated out of abovementioned methods. Furthermore, manufacturing technology allows production of some rare and unique wooden materials out of dry ‘dead standing pine’.
Log builders appreciate northern Pine wood, because wooden houses from Finland are not only well built and durable but pleasant on the eye and ecologically friendly. The Finnish method of house manufacture consists in not only the use of first-class materials but also a unique technological process of drying and processing timber. As a result, a house built from such material is extra resistant to climatic influence and has a long life.
Log Houses System
Finish log house collection includes cozy log houses, spacious wooden homes and cabins, as well as grandeur mansions, all with rustic or modern look. House log home system is developed since the 1980’s using polar pine or spruce as raw material for log walls and guarantees high quality and durability. Log wall constructions are energy efficient, ecological and durable. They are also a builder’s dream as the log house is fast to install, and set up. Massive log wall is the most traditional way of building a log house. The wall structure includes nothing but the wood and the sealants or joints between log layers. All logs are connected with wooden dowels and metal bolts which run from the top to the bottom of the wooden log wall. A wall structure can withstand -40C temperature and maintains a comfortable level of internal air humidity.
Thanks to the qualities of the logs, the inside air in the residence remains healthy and constant all year round. Some advantages of log system are listed below:
• Fast assembly due to pieces manufactured with high precision
• No settling
• No need to adjust after construction works
• Allows to construct higher buildings
• Architectural freedom, pure & elegant design
• The building material of the future
• Lamination process stabilize the wood, logs don´t deform or twist
• Solidity and strength
• Perfect moisture control
• Less cracks on surface
• Less and limited settling
Log Frame Technology
Wall cross sections are laminated squared log, laminated round logs and highly durable cross-laminated log join together with corner joints. Planed wooden boards, milled by the longitudinal sawing of raw logs, are glued together. This is because when a tree trunk is sawn, the so-called timber ‘tension’ that has been building up between rings during the years of growth, is removed. If this ‘tension’ is not removed from a wooden log, it can become deformed or twisted during the drying process. After being dried, the timber is planed to the finest stage of purity. Finely dried pieces are glued by their length with the help of special glue and are again planed. They are then collected into a package and put under press. Different Log profiles have many different systems of joints such as cross corner, short cross corner and sheered corner.
In addition, non-settling log is the latest innovation in log house building technology. These logs are made from special multi-layered cross-laminated timber. Non-settling log innovation allows eliminating the phenomena of settling of the log frame made of traditional massive or laminated logs. This enables higher buildings made of wood. It also allows for mixing different materials such as glass, stone and steel elements together with wood in facades. Smart log is the future of wooden construction.
Extra insulation outside the log frame is also a possible choice. It raises the wood capacity to meet the highest U-value (heat transmission) requirements as the insulation layer can be widened easily. The internal log wall keeps the inside air quality and air moisture level optimal.
With this wall structure, you will have a beautiful wooden atmosphere throughout the interior of the house and the external insulation and its protective layers keep the log frame safe and sound from the changing environmental elements.
Extra insulation inside the log frame is also a recommended way of including additional insulation to log home. With this wall structure the internal wall surface materials can be chosen freely - main options are plastered walls or wooden panel clad walls.
The Cut-System Frame
In cut frame system also called prefabricated wooden structure, the laminated posts and beams bear the weight of the house and the pre-cut joints and wall studs complement the structures. High-tech CNC system allows the frame components to be cut into an exact pre-determined size and angles. They are notched and numbered with the help of the detailed constructional drawings, and can be erected in a relatively short space of time.
This cut system behaves as a real log building would behave. The structure of the wall, along with the wood-fiber insulation, allows the building to breathe in the same way as a solid log building would. All windows & doors are installed in the frame and sealed with insulation tapes to ensure airtightness. It helps to stabilize indoor air humidity by absorbing excess moisture and releasing it when needed, therefore creates a constant supply of fresh air which is beneficial to dwellers with respiratory problems like asthma.
The wood fiber used for the insulation material is very effective. It maintains a stable temperature and is also an excellent acoustic insulation. The structure and composition of the wall meets the stringent insulation requirements in most parts of Europe.
CU-system structures can be used to build all types of Villas, and houses. The timber frame system also allows the construction of larger houses with same structural properties.
For the exterior, it is possible to choose from a variety of material finishes, including wood, brick, natural stone, lime plaster or other finish.
The interior walls as well are covered by a chosen finish, or various materials such as wood, plasterboard panel (drywall) that could be combined with the wooden structure.
Advantages of log house
+Ecological and fast to build
+Clean indoor air: The log wall evens temperature changes and keeps the air humidity at an optimal level. It binds excess humidity from the indoor air and gives it out when the indoor air gets too dry. The respiratory organs’ greatest enemies – mold, dust mites, bacteria and viruses do not thrive in correctly built log houses because the optimal air humidity prevents their growth. According to the Finnish Allergy and Asthma Federation, the optimal level of air humidity is 25-45 % and log houses are the safest choice for many asthmatics and those who have been exposed to mold.
+Durable and energy efficient structure: The inside temperature of a log house is pleasant all year round, cool in summer and pleasantly warm in winter. Wood stores heat, and give it out slowly. The superiority of the log house has been noticed not only in the cold north but also in earth quake regions where log houses were the only buildings that survived the quake.
+A home that reduces greenhouse emissions: Wood is definitely the most ecological of current building material. When wood is used as a building material, it immediately functions as a carbon sink. A medium-sized log house consists of approximately 30 tons of wood. This amount of wood has absorbed the same amount of carbon dioxide (while growing) that is generated by driving a car for approximately 400 000 km. Finland has vast sustainably managed forest which grow annually 30% more than what is being cut from said forests.
Introduction to Kontio Log House
Kontio comes is based in an area close to the Arctic Circle where houses have to withstand very cold winters. Kontio houses are made from the Arctic Pine. This grows close to the Arctic Circle in the clean forests of Northern Finland and its slow growth maximizes the amount of extremely durable heartwood in every log. Kontio has leading expertise in massive wood construction technologies and is the world’s leading Log House Company. Kontio log houses comply with all the required health, safety, and environmental protection standards. In addition, kontio log houses are known for withstanding extreme conditions around the world, such as massive snow loads and typhoons, as well as earthquake. Over hundreds of years, massive pine logs have proven to be an excellent construction material for climatic architecture. In each Kontio house, logs are carefully chosen to meet the needs of that individual building. They take both the local climate and local regulations into account, as well as the customer’s personal design preferences. Every Kontio log is made with Kontio Arctic Pine as the raw material. Wood machining technology ensures that each component in every Kontio Log house is of the highest quality. Carefully dried wood has a low and consistent moisture content. They utilize the most modern technology, including robot machining, to achieve excellent dimensional accuracy. This results in visibly high quality. The high dimensional accuracy also improves the airtightness of Kontio buildings, which in turn ensures warmth and low energy consumption.
Kontio Heartwood also contains natural antibacterial and antimicrobial substances. In a growing tree these give it resistance to moisture, fungi and insects. The same substances also protect the wood used in Kontio log houses. This is especially important in locations with changeable weather conditions and high levels of rain and humidity. Kontio log houses are made to last generations and to continue legacy of building extremely durable wooden houses in modern way.
Kontio log houses are carefully designed to fulfil the energy efficiency requirements of today’s residential housing. They choose the best structural solutions to meet the demands of low-energy construction including log type, corner design, sealing technology, window glass, air ventilation and heat recovery systems, as well as additional insulation. Kontio log corners and joints as well as sealing systems have been tested in laboratory for tightness and durability. Corners have a big effect on the style of the house and, in addition to long log corners. More effective short and modern Eagle Corners and Neo corners are further offers. Another factor that reduces the energy consumption of Kontio log houses is wooden component’s airtightness. Airtight structures improve living comfort while lowering costs thanks to decreased energy consumption. The excellent airtightness of Kontio log houses is due to many factors, including state-of-the-art log profiles and double sealing technology. In addition, double sealing system is designed especially for rectangular logs. It continues unbroken along the entire length of the log and it is used together with pre-cut log corner joint insulation to ensure complete airtightness. For houses with round logs, they have also developed special profile-fitting airtight sealing solutions.
The thermal insulation capacity and the U value of walls can be improved using an additional insulation structure being installed on either side of a log wall, and coated with alternative surface materials to create a variety of attractive interiors and facades.
Furthermore, Kontio log house structure is Fire Safe. Although timber is a combustible material, in construction it performs well against fire. The good fire resistance feature of logs comes from the nature of the material: the natural humidity in wood protects it from ignition. Before the wood can ignite, the humidity must be evaporated. And in cases of fire, the burnt surface and charring of the wood actually slows down the spread of the fire. Furthermore, the log structures have been tested against fire and have high fire resistance classification values. The classification system is governed by international testing methods and standards.
Finally, Kontio log houses are an ideal choice for seismically active areas since they exhibit superior seismic endurance and the elastic nature of wood, combined with horizontal log construction contributing to safety in tremor prone areas. For decades, customers from seismically active regions such as Japan, Central Asia and Southern Europe have relied on Kontio’s engineering expertise and log construction technology to provide safe housing in challenging areas.