Log House technical data

Why choose a log house over a conventional construction in Corfu?

The main problem with houses in Corfu is mold due to the extreme humidity in the air, especially for vacation homes that remain closed in winter. A log house is the only type of house that can withstand this humidity and avoid mold thus providing a healthy and dry interior even during the most harsh and humid rainy periods in winter. Moreover, there is always a nice and fresh smell of wood.

Wood is resistant to fire and remains strong

Wood as a building material has a higher fire resistance than steel or concrete to what many of you think. The ignition temperature of conifers is ~250° C. In case of a fire, a carbon layer is created on the surface of the log that acts as a heat shield, thus preserving the underlying strength of the wood. After half an hour the wood under the charred remains intact.

It is remarkable that the strength of the wood is increased with heat because of the reduction of the humidity inside. It is also important that when high temperatures on the outside are reduced, the burning is self-limited. The conclusion is that in case of a fire, a wooden construction will last longer than a concrete one, depending also on the thickness of each log that remains unburnt. By smoothing the burnt surfaces or replacing the burnt woods, the construction can still be used without any problem. 

Resistant to earthquakes

Wood is flexible and elastic making it more resistant to landslides or earthquakes. The choice of wooden constructions made in countries with high seismic activity (e.g. Japan, Greece, etc) proves the advantages of log houses during an earthquake. The light weight of the wooden constructions, in combination with its high flexibility, have as a result that the forces of oscillation are reduced, making the constructions hard to collapse. Last but not least, in case that a log house collapses, the wood is safer than any other material. See an actual experiment with a 7.3 Richter magnitude simulated earthquake.

Heat insulation

Wood is a great heat insulator thus can significantly reduce your heating costs. Wood insulates 6 times better than a regular brick, 12 times better than concrete, 700 times better than steel and 2000 times better than aluminum. For example, if you lean against a wooden wall you will not feel as cold as when you lean against a conventional brick wall house. The heat insulation of a house depends on the thermal space of the construction materials used and the amount of heat that must be absorbed by these materials in order to start heating the inside of the house. The wood, as a material, has a small thermal space, in contrast to the conventional materials like concrete and stone that have a big thermal space, which means that a log house can be heated much faster. For example, a log house of approximately 100m² will reach the desired temperature of 22°C on the inside with external temperature 0…5°C in approximately 2 hours, in contrast to concrete and stone where it takes approximately 24 hours.

Wood is the best heat-insulator because of its surface which consists of many fibrous cells that include small quantities of stable air between them. During laboratory test, it has been proved that log houses have 24 – 46% less energy consumption for heating. During summer months the good heat-insulation that wood provides, operates in an inverse way resulting in a cool interior.

Kontio Log house Features

Kontio log buildings are built from slowly grown northern wood. The close grained quality and a large share of heartwood have proved to be the best construction material. Only large butt logs are accepted as the raw material for laminated logs. As for drying, it complies with current quality requirements (Log building. Quality requirements. Finnish Log House Industry Association, March 2001).

Laminated log

Laminated log makes an excellent construction material; It preserves the natural cell structure of wood. In addition, settling and cracking are minimal in a laminated log. Kontio laminated log is manufactured with a modern heat gluing method where dried timber billets are heated to about 70 °C and glued together while applying strong pressure. This ensures that the adhesive is absorbed deeper than the log surface, thereby forming a firm moisture permeable adhesive joint (1). The very durable heartwood is always on the outer surface of the log (2).

Samples are taken from every gluing lot for quality control purposes. In addition to the strength of the adhesive joint, qualities tested include the moisture permeability of the adhesive joint, which ensures a healthy and breathing indoor air. After gluing, the log billets are planed to profile. In the same context, a mild water-soluble wood protective liquid is sprayed onto log surface. It provides protection against possible weathering and molding for the period of transportation and the starting phase of construction operations. 

Tongue-and-groove log profile

A tongue-and-groove type recess, which has been cut in the shape of the laminated log, ensures a tight construction with minimal settling, thanks to dimensional accuracy and recess width (6). A separate space has been cut in the log structure for insulation (3), keeping it protected from storms and rains. A drip edge (4) in the profile ensures that the recess keeps dry.

Tightly locked corner joint

The dimensionally accurate locked corner joint by Kontio (4) as well as double insulation in the corner joint profile ensure a warm and tight corner solution.

   

Maintenance

The log walls are soaked with environmentally friendly chemicals at the factory which target on the protection from fungus, moisture etc. The other parts of the house are soaked with a corresponding protection liquid. After the house construction is finished, it is varnished on the outside, and if we prefer, inside as well. This is the only protection needed. As the time passes, these polishes are soaked up and the result is that after five to seven years (depending on the climatological conditions), only an outside maintenance is needed, without scratching any surface but simply with a paint-brush. This is much more easy and cheap in comparison to any other construction.