TIMBER FRAME PREFAB HOUSES
Building in different climate zones
Timber frame prefab houses technology origins are to be found in Canada. The climate of North America is similar to our, but the frame house design is suitable for different climatic zones and geological conditions: if changing different parameters of materials of isolation, then it is possible to adjust the house – build it in warmer or colder zone. The huge plus is that the timber frame prefab house is possible to mount even when it is cold outside.
The experts in the field of building in Canada say, that these houses if have been renovated, can serve 150-200 years. The stability of the wooden frame house is connected to its flexibility thus, it is seismically durable and can withstand earthquakes (for example, in Japan 75 % of livers use this type of houses, placing a high buffer pole in the middle of which the rest of the house is being constructed – the walls move around it, but remain intact). On the other hand, wooden frame houses cannot cope with strong hurricanes, what is very specific for the North America region. But in Lithuania for several decades the are built garden houses from the wood constructions, while in private houses’ sphere it comes slowly, but becomes more popular.
The efficiency of warmth
The average thickness of the walls of the wood frame houses is 20 cm, but, even in cold time without heating, the temperature lowers only form 2-3 ° С in a day. It is not hard to heat wood frame houses and maintain the necessary temperature. The loss of warm depends on the house impermeability. That is why the factor such as this is so important.
For example, in Lithuania traditionally in use are brick and concrete flat houses, which gave us uncertain apprehension – if a house has thin walls, it does not save warm for a long time.
Impermeability of the air is the most important factor of thin walls
The warmth in the premises rises upwards from the heating devices, creating pressure on the existing parts – ceilings, walls, and windows. In the smallest gaps the warm air exits out while air at the same time as the ground is drawn and through the floor, window or door openings, cold air enters the interior and the room must be heated again.
Heat loss can be reduced by increasing the thermal resistance of the bulkheads. IN the USA company “Architectural Energy Corporation” was made a research: calculated the heat loss, using non-insulated building constructions. Later the same constructions were was covered with waterproof and warm insulation material. The research has shown, that on the basis of the thermal energy savings is tightness.
By increasing the heat resistance of the sealed insulating material layer by more than 100% (increasing the layer from 10 cm to 20 cm), heat savings only reached 3%, proving that these investments were ineffective. According to the research results, it can be concluded that it is more efficient to invest in the construction of the house as a whole since even a completely thin layer of airtight insulating material retains the leakage of the warm air stream.
Steam should be controlled by the insulation material, which goes up from the humidity construction, this doesn’t let to rot, mold or dry out too much. Steam and air should be evenly going through the insulation material. Since the drying process of building materials is relatively slow, the air resistance of such a durable insulation material may be small, but it can be provided with airtight materials.
Choosing enough insulated airtight materials, it is possible to lower the circulation of the air in the partitions, this way decreasing heating (winter time) and cooling (summer time) costs.
The building of a timber frame prefab house
The building technology of the timber frame prefab house determines different material functions – bearing capacity, separation, insulation. Each element has its own function and possible opportunities: various materials have their own structure’s minimum thickness, its thermal energy efficiency, moisture resistance, and sound permeability.
Traditionally, brick, wood or stone wall raw materials have to do different functions at the same time (structure providing, warmth, and sound insulation), which determines several concrete building conditions: the natural drying and shrinkage of the building, the wall thickness is sufficient and the bases are heavy, and the total construction time is long.
Foundations can be the monolith or on the piers, but they shouldn’t be massive for being stable. It shortens the time of building and reduces costs.
Usually, timber frame prefab house is from one to two floors. Houses such like these are light and small, there’s no need for the huge number of the material for the exterior. This is one of the benefits in comparison to panel houses’ building – flexibility is the implementation of various architectural needs.
One of the possible disadvantages of this house could be acoustic characteristics. Through the building process, there are special seal settings, which can work as a sound insulation. The insulation of the sound determines the filling. Often there are problems with flaws: if the house is with two floors, then people, for example, can complain about too loud steps on the second floor. This problem can be resolved if we choose enough durable wooden overlay, on which later will pour the concrete floor. In a building, using wooden frames, it is possible to build the even five-floor house, but usually, they are used for one or two-floor houses.
Frames are produced from the dried calibrated wood. Because of the good characteristics, builders choose to use conifers’ wood. Fir wood is flexible; pine tree wood is fragile, but our modern technologies let us protect the wood from the adverse effects of the environment.
Partly finished house cost without foundations and painting works could be approx. 500 – 700 EUR for the m2 and more. It is possible to set up the frame in several weeks. An important requirement for building house such like this are good weather conditions for the frame house mounting, because, while mounting wooden constructions, humidity and frost can influence them.
If the decision is to build a wooden frame house, it is not recommended to stay the house for several years without windows and doors, because the wood will not withstand it. That’s why it is necessary to plan all the building works and have enough money to finish the work.
Then starts fixing of the frame (very suitable is calibrated wood), placing elements successively in 60 cm one from each other and fastening them with nails and screws.
In accordance to needs of the project, in corners and other places, it is used the thicker wood material.
Between the foundation and the lower beam, which goes through all the foundations, a rubber gasket is inserted, which eliminates the appearing of the humidity and later provides the impermeability of the air.
Later affixes the crown and sets up a ceiling. It high can differ between 1.95 till 2.45 m in accordance to the fact, will be used concrete floors and planned several partitions. If one-floor house is planned to be built, then it has to be considered the question about the building of the roof.
Despite that, in wooden frame houses, it is possible to use different panels (plywood, wood chip, wood fiber, gypsum, OSB), because it provides the strength and stability of walls.
- Small weight of the construction (wooden frame house is 5-6 times lighter than the brick house)
- Relatively short time of the building process
- Availability of materials
- Ability to carry out various architectural plans by constructing an individual design and interior planning house
- In the process of building, there is used not a huge amount of building equipment
- All the inner communications (canalization, water, heat) are built into the walls.
- Easy to modernize
- Relatively not huge costs
- An advantage of the eco house – nature-friendly and renewable materials
- Is not durable against hurricanes
- While mounting wooden constructions, humidity and frost can influence them
- Is important to make house impermeable for the reasons of, when start to live, the heat couldn’t go away and to do not have problems with a bad insulation.
There are fulfilling heat insulation and insulation materials are chosen before the mounting of the panels. Firstly, inserting mineral wool and stone wool for thermal insulation, then a film that protects against water vapor. On this stage, there are mounting electrical installations.
Walls are finishing with mentioned panels, at the same time combining in ordinals, which helps to save the heat.
At the end, the house interior and exterior works are accomplishing.