Foundation for the glulam house
What eco style means in the building industry, why is it becoming more and more popular nowadays? Why more and more people start thinking of moving to the countryside and building their own wooden home? The one and the only answer to those questions is the condition of ecology in the city today. Nowadays the construction of houses from timber becomes more and more popular, shaped timber and glue laminated beams are more often chosen as the most popular building material. Wood home is not only ecological and economical but also is simply beautiful and has attractive design. More people are building wood construction not only as homes for summer but as a country house for permanent stay. The growing area of the house, complicated design and several storeys encourage house owners to think thoroughly about the foundation construction choosing. In this article we will try to help you in this tough choice. We are going to describe the main types of house foundations that will better fit the wooden house.
So it goes without saying that by all means one of the most important parts of the house is the foundation. It does not only perform a function of bearing and supporting of the house, but it also will influence its durability and reliability in the future. It is very important to choose a good variant for your house taking into consideration the material (shaped timber or glue laminated beam). By choosing the best and suitable foundation for your wood home construction you will avoid many crucial mistakes that can cause structural failure of the fundamental construction.
There are several types of foundation that will fit the construction of house made of wood.
Wooden houses have light weight. The foundation for the building made of timber should not be very complicated in its construction.
The most common types of foundation for wood home are considered to be the following:
- post footing
- piled footing
- girder foundation
Before you start choosing and building foundation, you will need to collect some important characteristic, including soil parameters, environmental conditions of the region, the angle of slope and other. It is a very complex and time-consuming process, that is why it is important to make thorough preparation work. Only after you collected all the necessary parameters you can proceed to foundation building.
So as it was mentioned before, among the most important characteristics are:
-structural design load on the foundation and soil
-the total house square
-the angle of slope on the territory
Now we will try to describe in detail the important parameters you will need to take into consideration before the house foundation construction.
Pedogenic study on the piece of land
The ground study on the piece of your land is very important, as every building is connected with the soil. It is clear that every building and house should have strong support and be stable. There are so many vivid examples when the lack of information about the ground on the piece of land resulted in the construction failure, just remember the Tower of Pisa.
The important information will be:
- the angle of slope of the ground surfsace
- chemical and physical properties
- water drainage and runoff
There five main types of soil:
1. Sandy 2. Silty 3. Clay 4. Peaty 5. Saline Soil
The type of soil characterizes the press on the surface of the foundation. During the season of frosts and rains external forces rise, which is determined by the heaving properties. When the amount of water in the soil rises, the force on the foundation increases as well.
The soil is divided into two types according to the ability to retain water:
- heaving: this type includes clay, loam soil, fine-grained sand with high dust fraction content,
-non-frost heaving : medium-grained and grained sand. This type of soil has gravel in their structure.
Another important factor is groundwater occurrence, it stands on the same level of importance as ground nature and structure and its porosity.
At this rate, a significant impact, in addition to its nature, structure and porosity, provides the level of groundwater.
If you are competent in building you can build the house foundation with your hands. After you got all the information about the ground on the piece of land you should make a proper calculation of the load. It will consist of the total weight of the house and the characteristic temporary load, depending on climate zone. The total weight of the home is calculated as the sum of the weight of walls, roofs and floors. Their weight will be characterized by their material and size. Sometimes it is not so easy to make this calculation. In any case you can always consult professionals with the question of soil type interpretation or total construction weigh calculation Choosing the type of the foundation
After you received all the information about the ground parameters and other important information you can start the process of foundation type choosing. As the wood construction has light weight we included in the article the most common types, that are suitable for the home built from a timber. Post footing:
This type of the foundation is the most traditional and the cheapest for the foundations for wooden houses. This structure has been improved due to modern building materials usage. Post footing can be easily used for the glulam house. Post footing is made of concrete blocks (the minimum size of 200 × 200 × 400 mm) or bricks. Concrete can also be poured into the mold or asbestos cement pipe. They are made on the sand bed. This type of foundation has the form point construction, and is placed at points with increased load.
This type of foundation is common for light-weight construction that are built on heaving soils or frozen ground. This construction is good at load transfer. Usually pillars are placed at the distance of 120-200 cm with the pot bottom in the ground 50 cm, the sand bed is 20-30 cm. sometimes dumping is performed from cement-sand screed. These are the most widely used construction.
The distance between the pillars is calculated from the length of the wall, the only recommendation is that it should not exceed 3 meters. It is very important to calculate the number of pillars that will be optimal for some particular building. They should be installed to a true vertical, this is made mainly for a best possible load distribution.
Post footing will be the best variant of the foundation if you have a small light house, or you choose the foundation for a sauna, it will be a good solution for the soil is exposed to freezing. Piled footing
If you piece of land is has marshy ground or ground level differences the most suitable foundation time for your log house will be piled foundation. Installation work in this case is very complex and it is impossible to deal with it on your own. You will need to use special equipment. The work with piles built in place is almost impossible without special machinery.
The process includes:
- drilling machine makes holes in the ground, they are placed on the perimeter of the building
- special hydraulic hammer drives concrete piles into these holes
- log house is placed on the piles in a special way
This type of house foundation will be suitable for the piece of land where there is a slope of more than 50 cm or if there is in the area of floating ground. Girder foundation
This variant is the most common in house building. It is the most widely used in the construction of the foundation for wood homes. According to the depth of occurrence girder foundation is divided into:
- low ingrounded, when the depth is over 70 cm
- inground, when the depth exceeds the depth of freezing of the ground during the winter period.
Due to the installation at different depths, you can select the best suitable variant of the foundation according to the soil characteristics and the house construction type.
When building girder foundation it is important to observe several rules. First of all it should be a hard closed-in construction. It also should be a united single construction weather it is made of blocks or is monolithic. The optimal width of the foundation for the wooden home on each side is considered to be the width of the wall plus five centimeters. Precast girder foundation
Precast girder foundation is place on a sand bed and represent a construction made of concrete blocks. It is built along the perimeter of the wooden construction. The blocks are fastened together by cement. This foundation can be made on the soils of any kind. The common depth of coverage is 50 cm.
Though the construction seems to be very simple, it is not easy to build. To move heavy blocks you will need to rent special equipment. But for a small construction the foundation can be of Special sizes 200 × 200 × 400 mm and weighs up to 32 kg. Monolithic girder foundation
If you choose monolithic girder foundation you should understand that choosing it will lead to some extra money spending and, in general, it is labour-intensive process. Moreover it has a long hardening process- at least 28 days.
If you are thinking about the depth of the foundation placing, you should remember to take into consideration the following fact: side surface of the foundation experience significant pressure on the depth. And if your house has a light weight, the foundation might be just squeeze out of the ground under the pressure on the soil, which will ruin all the construction of the glulam home. In this case, it is important to observe the principle of golden mean. Therefore, monolithic girder foundation is a suitable variant for large and heavy two- or three-storey houses . in this case the high cost of the construction will be reasonable decision.