The foundation is the basis of the building, the correct manufacture of which depends on the duration of its operation. There are many options for different foundations. Quite often there is a foundation based on the use of logs. We offer you to familiarize yourself with the features and technology of erecting a foundation from logs.
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Columnar foundation is widespread due to the ease and speed of its construction. For its manufacture, different materials are used, such as concrete, blocks, iron, building stone. However, the most affordable and simplest way to make a columnar foundation is wood. In order to build a foundation of logs, a base is dug under them, into which wooden supports are installed.
Among the advantages of building a foundation from logs, we note:
- ease of work;
- a foundation made of logs, the price is very affordable, compared to a strip type of foundation;
- simplicity and accessible material;
- fast time frame for the construction of the foundation;
- cheap foundation;
- the duration of operation is more than 20 years;
- the possibility of replacing damaged logs.
Despite this, the foundation for logs is characterized by the following disadvantages:
- instability of the tree before moisture and decay;
- the need for processing with special means or performing wood firing;
- the possibility of building on such a basis small buildings, baths, gazebos;
- the need to build a sand cushion and ensure proper waterproofing.
The most popular option for the construction of such a foundation is larch. A log foundation is widespread in the process of building baths, log cabins or small log houses. This version of the foundation is distinguished by a high frequency of use, primarily due to its cheapness and ease of manufacture..
It is larch that has a high antiseptic effect, so the duration of operation of such a foundation remains at the proper level. After processing the material with special compounds, its service life increases to more than twenty years. However, the foundation is erected only from the lower stem part, called the butt. The minimum value of the diameter of the logs is 20 cm.The logs are laid in the ground to a depth of more than 80 cm under the load-bearing walls and half a meter under the inner walls.
Important: Before installing the logs in the ground, they need mandatory treatment with antiseptic compounds. Thus, it will be possible to protect the surface of the tree from decay..
At the same time, wood processing is carried out not only on the part that plunges into the ground, but also on the ground part, which is 30 cm above the ground.
The key to the long-term operation of the log foundation is the correct preparation of the logs for installation in the ground. The preparation of the pillars of the chairs is carried out in the autumn-winter time. Before processing wood with an antiseptic, they are sanded. Next, you should take notes on the log and indicate the upper and lower sides, depending on how the tree was growing. There are several options for preparing a tree for installation on a foundation. Possible use of firing or chemicals.
By firing, the wood is protected from contact with the surface of the ground and from susceptibility to mold. A blowtorch or open flame is used to perform firing. Burning is carried out on that part of the tree that is set in the ground and 20-30 centimeters above the ground.
However, before starting work, coat the baked surface with clay. The thickness of the clay layer should be about 1 cm. Please note that the logs are fired over very low heat, please note that the thickness of the crust that forms during firing should not be more than two centimeters. Next, the post is processed using bitumen or thick resin.
The second preparation method is easier to execute. To perform it, you will need special chemical compounds with which the tree is treated before it is installed in the ground. In addition, among the advantages of this method are noted:
- the safety of its use, since it does not need to be in contact with fire;
- fast lead times.
Try to choose high quality compounds that do not corrode steel fasteners. In addition, antiseptics must be free of environmentally harmful substances and must have a neutral odor..
In addition, some of the antiseptics are used to treat the entire pillar and not only protect the tree from external factors, but also decorate and decorate it. Since the pillar will be in close contact with moist soil, the antiseptic should not be water-based. It is preferable if the antiseptic is of organic origin. Otherwise, the solvent will wash off the surface of the wood with water over time. It is possible to use oil-based antiseptics, however, one should take into account the fact that they are highly toxic.
To build a foundation from logs with your own hands, you will need:
- wooden logs;
- pillars made of wood.
Installation of wooden poles is carried out in the most loaded areas of the building: at the corners and intersections of the load-bearing walls. The step of installing the logs is 150-200 cm. During the construction of a log foundation, it is necessary to strictly follow all instructions and technologies. The support pillars are fixed strictly vertically.
When determining the depth of the foundation and the step of installing the logs, the following factors are taken into account:
- climatic features of the region;
- soil type and groundwater level;
- weight of the future house.
The wooden support is a wooden pillar more than 80 cm deep in the ground, a log that is above the ground and a small margin, which is necessary for the same sawing of all pillars.
The optimal value of the installation of the pillars in relation to each other is 200 cm.When determining the optimal number of support components, one should be guided by the bearing capacity of the soil and the total weight of the building structure.
Here is an example of calculating the number of logs installed as a foundation. If the total area of the soil is 50 cm, and the diameter of the timber is 25 cm, then with the bearing capacity of the soil of 2 kg per square centimeter, the bearing capacity of one column will be 1,000 kg of the total weight of the building structure. In this case, to calculate the number of supports, it is enough to use this method..
Work begins on the manufacture of a log foundation by digging a pit for the installation of poles and the installation of sand cushions in them. If larch acts as a material for the manufacture of pillars, then the minimum depth of the pit for the foundation is 40 cm.To determine the exact value of the depth of the pit, the diameter of the log should be multiplied by 1.5. For example, with a log diameter of 25 cm, a hole 38 cm deep is sufficient..
There are several ways to dig holes:
- using a shovel is more time consuming but less expensive;
- specialized equipment will help to equip pits for the foundation with high quality and in a short time.
The next step is to make a sand pillow. Its thickness is determined individually and is about 20 cm.The process of creating a sand cushion is mandatory if the soil does not differ in hardness, since it is sand that allows you to evenly distribute the load from the house to the ground.
After installing every two centimeter of sand, it is moistened and tamped with special auxiliary tools.
The next stage in the manufacture of a foundation for a rounded log is the installation of supports in the ground. However, wooden supports installed in the ground must be properly waterproofed. Therefore, special oil solutions are used for wood processing. Before laying the tree inside, you should wrap it with a waterproofing material in the form of roofing felt or roofing felt. Each layer of waterproofing is glued with bitumen mastic.
Thus, it will be possible to prevent contact of the soil with the tree and it will be possible to increase the duration of the foundation. A fairly simple way to waterproof a wooden support is a waterproofing stocking. It will not only protect the tree from moisture, but also improve its resistance to frost and heaving of the soil..
Installation of wooden supports is carried out in a previously prepared base. In this case, the supports are installed strictly vertically. Installation of wooden posts is carried out in the longitudinal direction in relation to the walls. Therefore, in the corner sections and at the intersection of the load-bearing walls, lighthouse posts are installed. A rope is pulled over these pillars.
Further, intermediate supports are mounted. At the same time, the verticality of their installation is checked using a plumb line, and horizontal – with a cord. In order to increase the stability of the support and increase its bearing properties, the lower part of the support, made of larch, is installed on a cruciform wooden part. If the foundation is buried, then a concrete base should be arranged at its bottom. To build a cross for the supports, you will need two wooden blocks, each 700 mm long. They are interconnected in a cross direction. The connection of the support chair and the crosspiece is carried out using steel staples.
In order to increase the stability of the support pillar inside the foundation, a groove is made in its lower part, and a spike is made on the upper part of the cross piece. Thus, the reliability of the connection is increased. With the help of this design, it is possible to significantly increase the support area and increase the strength of the foundation before soil heaving during severe frosts..
In order to increase the reliability of the deepening of the wooden foundation, a monolithic concrete cushion is arranged inside it. At the bottom, a cushion made of sand, concrete mortar, about 20 cm thick, is poured, preventing it from hardening. The pillar is immersed in the concrete base by 10 cm. Then the wooden chair is fixed in concrete. After its hardening, work on the arrangement of the foundation continues..
Installed poles must be reliably protected from rotting and moisture accumulation around the supporting parts. Therefore, to fill the space between the posts and the soil, coarse materials such as sand, crushed stone, gravel or broken brick are used..
Backfilling is carried out gradually, the thickness of each layer is about 20 cm, while each of the layers must be carefully tamped. After filling the pillars, their additional alignment is performed.
The tops of the pillars are adjusted to one level by aligning them horizontally. After that, antiseptic treatment of the end sections and their waterproofing are performed. To waterproof the supports, use roofing material, a special membrane or birch bark.
To connect the columnar foundation and the lower strapping, a spike hole should be formed on each of the pillars. The spike section in the transverse direction is about 50×50 mm, and the height is the same as the bars of the lower harness. Before the walls are erected, the logs are laid on the foundation, on which there are previously prepared spike joints.
The larch foundation is an ideal solution for the construction of a wooden house or a bathhouse from the same material, thus, the life of a wooden foundation will be the same as the duration of the building itself. The option of erecting a wooden columnar foundation for the construction of temporary outbuildings is possible. Installation of high-quality, correctly processed wooden supports is a guarantee of foundation operation for up to 25 years..
If the wooden foundation fails, then to replace it, it is enough to install a pillow of concrete blocks under the house and replace the wooden posts.
Log foundation video: