Frame houses are gaining in popularity. Despite the simplicity of the construction of the structure, it is very important to organize a solid foundation. In order not to be mistaken in the choice, you need to know what type of base is used where, and what affects the choice.
Overview of suitable species
The demand for frame buildings is growing for many reasons. First of all, these are tight deadlines, and a small budget for building a house. At the same time, the total cost of a typical cottage with an area of 90-100 m2 will be about a million rubles.
The weight and total load of the structure on the foundation for a frame house is significantly lower than in buildings where the most used materials are used. Therefore, there is no need for a complex base for a lightweight construction..
For the construction of houses, foundations of the following types are used:
Tape bases are more common. In this case, the floor is organized on the ground or wooden logs, but always with a ventilated underground.
If the soil is of the weak type, then a reinforced concrete frame is used for the base plate. It is he who distributes the load over the available area. However, it is impossible to organize the basement in such a case..
The most inexpensive option for organizing a basement in a house is a pile-screw or columnar-tape (columnar with a tape lattice) foundation. Such a base can be made of asbestos-cement pipes, log posts or reinforcement. Reinforcement post has many advantages over others.
The choice of the desired foundation is carried out by the engineer. It focuses on the bearing capacity that the soil demonstrates, the depth where the groundwater is located, and other parameters..
The device of the pile-screw foundation does not have seasonal restrictions, and the use of special additives allows the foundation to be poured into frost, but not below -15 ° С. It follows that the cold does not in any way affect the speed and possible time frame in which it is planned to build a frame house..
Type of shallow foundation, which is used to provide a continuous, even (or sometimes stepped) strip of support for a linear structure, such as a wall or closely spaced rows of columns.
Strip foundations are used for most frame structures, but are most suitable for soils with relatively good bearing capacity..
Such a base has both pros and cons.. A number of factors can be attributed to the positive:
the simplicity that the design demonstrates;
can be built without using expensive tools;
The disadvantages are the relatively low durability, high cost at the completion of construction (there is always a need to perform additional work manually, namely: fill the soil between the strips and level it, build the floor, etc.), in addition, it is impossible to make a monolithic fastening of the floor to the base.
Pay attention to the following details:
when planning construction, take into account the required width of the foundation strip indicated in the building codes;
the concrete solution must meet the requirements for compatibility with soil chemicals;
the thickness of the concrete strip must be equal to or exceed the projection of the outer side of the wall, but not less than 15 cm;
the height of the step should not exceed the thickness of the foundation;
the strip of the foundation protrudes beyond the edge of the supports, the chimney forms the side of the wall to the same extent as it protrudes beyond the outer surface of the wall.
Preparation for the construction of a strip foundation includes a number of steps.
When the trench is ready, cover the sandy base, gravel at the bottom.
Foundation formwork is made of planed boards with a thickness of approximately 40-50 mm. When erecting the formwork, it is necessary to constantly monitor its verticality. Recommended projection of the frame above the ground is 30 cm.
The next step is to strengthen the foundation of the building.. Reinforcing rods with a cross section of 10-12 mm are fastened with a specially designed knitting wire so that the sides of the square cells are 30-50 cm. Both steel and fiberglass elements can be used for reinforcement. When placing reinforcement in a trench, follow the indents from the edges. The optimal spacer is 50 mm. In this case, the reinforcement will be most efficiently located in a monolithic state..
Pouring of concrete is carried out immediately, if a ready-made mixture is used, or in layers, if the concrete is prepared independently.
Concrete preparation: cement is mixed with sifted river sand in a ratio of 1: 2 or 1: 2.5, then diluted with water to a liquid creamy consistency, after which it is poured onto prepared gravel. The amount of crushed stone corresponds to the amount of sand. Stir the mixture so that all the crushed stone is moistened with the solution.
Pour the solution into the prepared formwork. They pierce it in several places with scrap metal and seal it with a wooden block to remove the remaining air from the voids..
The top layer is leveled with a ruler or spatula.
Sprinkle concrete with sifted dry cement, you can do this through a sieve. This method allows faster hardening of the top layer, prevents its erosion and cracking..
Cover the concrete with burlap or covering material, leave for 3-4 weeks.
In dry weather, the top layer of concrete must be wetted to prevent drying out..
If the pile foundation is based on steel pipes, it shows excellent results in operation:
is highly resistant;
resists heaving that can destroy concrete structures;
is characterized by simplicity of assembly and installation – they can be installed on any surface without the need for complex construction equipment;
this basis is not limited to soil types;
a structure with such a foundation can be quickly expanded;
designed for a long service life – at least 100 years.
Pile foundations are divided into different types, depending on the types of materials and how they sink into the ground..
There may be several mounting options.
The structure is immersed in the ground using various tools: hammers, tongs or submersible equipment with a vibrating effect. Mainly solid square bars are used here..
Metal screw – screwing into the ground. For this, blades are provided on its surfaces.
In the ground is done hole where concrete is poured.
Piles can be placed under the future house in different ways:
under the walls of the house in the form of stripes;
as separate elements – in the most important places of the building;
in groups – if necessary, create a support for heavy structures;
like a solid field, holding grillage.
Piles may vary depending on the materials of manufacture (metal or wood, concrete, reinforced concrete). Parts are often distinguished by the presence or absence of voids in the structure; they can be different in cross-sectional shape – square, round.
With a monolithic foundation, a foundation pit is first pulled out under a frame house. Sand and gravel are poured into the bottom. Everything is well compacted and wetted with water.
Formwork is installed along the edges of the poured area. It is imperative to use additional supports, otherwise the mortar can simply break the boards under pressure.
Reinforcement mesh is laid on the gravel. It is formed from individual elements connected by a wire or nylon tie. There should be two such grids..
Only after their installation is everything poured with concrete. Today it can be freely purchased ready-made, which can significantly save time..
If we talk about the design of such a base for a frame house, then it consists of supports that are buried 1.5 meters into the ground. Above soil level, the pillars should be visible 50 cm.
Supports are mounted in the corners and where the walls will adjoin each other. The distance can vary from 1.5 to 3 meters. It all depends on the type of soil and the total weight of the structure.
In addition to the pillars, a grillage is organized. It is he who is responsible for the even distribution of the load..
Such a foundation can be with a strapping of a log or a bar.. If the weight of the house is impressive, then metal beams or a channel are used..
ideal for areas where ground heaving can be observed;
a small amount of earthworks;
you cannot organize a basement;
you cannot build a building from heavy materials;
cannot be used on water-saturated, clayey and peaty soil;
the house can only be one-story.
Most often, a columnar foundation is made of concrete using corrugated reinforcement. There are other materials:
Which one is better to choose?
To understand which foundation is better in a particular case, it is worth taking into account the following data:
what period of operation is required;
how high the groundwater is;
the level of soil freezing;
soil quality at the construction site.
A monolithic slab will be an ideal solution if there is loose or floating soil on the site. If the soil is normal, then it is better to use a shallow tape type of base..
The dimensions and thickness of the foundation are calculated at the preparatory stage, when the project of the frame house has already been determined. When calculating the foundation, many factors are taken into account, the load of the house and the nature of the soil are assessed. Takes into account the depth for a two-story house, one-story house or with an attic.
The weight of the house structure is determined by multiplying the volume by the density. The density of the frame house is already known, given the material used.. The volume is obtained by multiplying the following parameters:
It is not very difficult for specialists to calculate the weight of building materials that will be used during construction, therefore, the “power” of the foundation can be calculated quite accurately.
DIY building tips
Compared to a slab foundation, there are several obvious advantages when using a strip foundation for a one-story building..
Here is a list of the most famous.
Since the strip area is significantly less than the total floor area, earthworks are localized, and the total volume of the moved soil is significantly reduced.
Stripes are geometrically smaller than a full-size slab, therefore, much less concrete is required during the casting process. In addition, fewer reinforcing steel bars are needed..
No special equipment is required for the construction of the drilling foundation. You can use a simple garden drill that will help you install all the necessary elements into the base..
Pre-mark the places indicated by the contour diagram, drill with the tool, and make a hole about 100 cm deep and 20 cm in diameter.
To increase the support area, which, in turn, increases the bearing capacity of the rod, make the well bottom lengthening. You can use a sapper shovel and crowbar. Use a drill to pull out the ground. Pour some rubble or gravel to the bottom of the well and tamp it.
To increase the strength of the structure, reinforcement is made using metal rods.. For one pile, you will need at least three rods with a diameter of 12 mm. The length should be chosen so that they are about 10 cm above the ground level.
Then the ends are included in the beam that connects the pile foundations. The well is filled up with reinforcing concrete mortar, which must be well rammed.
The finishing of the foundation depends on its type. It can be all kinds of cladding with natural stone, plastic panels.