Original and cheap foundations. Do-it-yourself saving methods, high-quality and cheap foundation
The very process of laying any foundation involves several stages:
- Site preparation and foundation marking
- Excavation, digging trenches, drilling poles
- Preparing the foundation cushion
- Reinforcement cage assembly and formwork construction
- Concrete pouring and leveling
I talked about what types of foundations for a house exist today in one of my previous articles, so I will not dwell on this.
In this article, I will tell you in detail and step by step about pouring the most popular today - strip foundation and about the distinctive features of the stages of pouring other types.
Filling the foundation with your own hands
There are several types of strip foundations, but the do-it-yourself pouring technology is almost the same for everyone.
Pouring concrete into a trench always starts from the corners, and then the rest of the voids are filled.
The ideal conditions for pouring the foundation under the house is the automatic mixer access to all corners of the house.
The mixer drives up to the corner and the pouring process begins. At this time, one person should hold the gutter, guiding it, and the other (preferably two) - help the concrete evenly spread over the trench using a shovel, for example.
In order to expel air from concrete, it is necessary to use a deep vibrator, if there is none, then it is necessary to vibrate using improvised methods. You can vibrate with a bayonet shovel, this vibration is called the bayonet method. A good result can be obtained by tapping with a hammer on the reinforcement frame, or on the formwork (not much!).
After the trench is filled with concrete, it is necessary to trim the concrete in the right places before the concrete has “set”. After the concrete has become "Crumbling" - it is not advisable to touch it.
As I said that pour the foundation under the house it will not be difficult, at this stage we examined in detail the pouring of the strip foundation, the stages of which in most cases are suitable for pouring any type of foundation.
Features of pouring a columnar foundation under a house
Distinctive feature columnar foundation is that the foundation does not consist of a monolithic tape, but of pillars that are connected with a monolithic tape.
In this regard, after marking, the pillars are drilled using an auto-drill or a hand drill, the pillars are reinforced with reinforcement with a diameter of 10-12 mm, with the release of reinforcement 15-20 cm above the level of the post.
After pouring the pillars, a formwork for the grillage is constructed, connecting all the pillars, a reinforcing frame is created and concrete is poured into the formwork.
It should be recalled that the columnar foundation is constructed for light structures and in "good" soil.
Features of pouring a slab foundation
A distinctive feature of a monolithic slab is that such a slab is located under the entire structure, and not just under the walls of the house.
In general, building a slab foundation with your own hands is not a difficult process, but it requires a responsible approach, and I believe that it can be transferred to a separate article.
One of the types of a monolithic slab is a slab foundation with stiffeners; the technology of pouring this type of foundation is not much different from the usual one.
The markings are made around the perimeter of the house, then the soil is removed under the future house, to the depth of the future slab + the thickness of the sand cushion.
Then it is necessary to build a sand or sand and gravel cushion, followed by tamping.
The reinforcement frame is knitted in two rows in the form of a mesh.
Filling occurs in much the same way as with any other type of foundation.
Methods of filling and methods of saving the foundation of the house
Depending on the use of your own labor, you can fill the foundation in three ways:
- Lay the foundation yourself, using only your own labor. This, of course, is a laborious process, but not so much that you cannot cope with it on your own. Ideally, 2-3 people will handle all the steps effortlessly.
- Use partially someone else's work for some stages of pouring the foundation. This method is most common when building houses on your own; it involves the use of hired workers at especially difficult stages of work. This will save on your own labor, but financially it will be a little more expensive.
- Entrust the pouring of the foundation for the house to professional workers. This is the most expensive method of pouring, but in this case, you will not have to do anything other than come to the site and control the process of laying the foundation, because even professionals sometimes do not adhere to a strict technology for their own benefit.
- If you hire workers to perform certain stages of pouring the foundation under the house, then it should be borne in mind that the most expensive stage is digging the soil and pouring concrete. If we talk about digging, then it's up to you to decide, this is a laborious process and whether it is worth saving on it. Well, on pouring the foundation, you can save a decent amount if you invite a friend to help. In fact, pouring concrete is a messy, but not very complicated process, which two or three of us can easily cope with in half a day, saving about 500 rubles on this. with a cube of concrete.
- On a strip foundation, you can save on deepening, if you do not have a heavy and small house (for example, a wooden one), then you can make a shallow strip foundation instead of a recessed one.
- On a slab foundation, you can save money by making it thinner, but with stiffening ribs. I talked about the slab foundation with stiffeners in my previous articles.
- When laying a columnar foundation, you can only save on labor, because it is already the least stable in comparison with its counterparts.
- In some cases, fiberglass reinforcement and its use will save a little on the foundation.
At the design stage, the question arises, which foundation is better to choose for the future home. The solution to this issue is important for the developer. The cost of the foundation foundation of a structure can be one third of the total estimated cost of construction, so you need to choose the most reliable and durable foundation. In determining better foundation, the owner of the future home should always be guided by the compliance of the price and quality of the foundation foundation.
The main factors determining the choice of the foundation
Consider the main conditions affecting the choice of the foundation for the house. The properties of the subsoil are determined by its composition, the level of groundwater and the depth of soil freezing.
Soil composition
According to their bearing capacity, soils are divided into three groups:
Weak soils
Peaty, sandy and clay soils... For example, peat bogs are so unreliable that they often avoid the construction of any structures.
Clay soils are generally prone to swelling. Heaving, that is, a sharp increase in the volume of the soil under the influence of moisture saturation, can cause the foundation structures to be pushed out to the surface of the earth. In the same way, frozen soil layers affect the supporting structures of the structure.
Weak sandy soils do not have a high bearing capacity and can contribute to subsidence and destruction of the foundation of the house. On soils of this type, pile foundations with a grillage are laid, monolithic reinforced concrete slabs, both resting on piles and without them.
Rocky foundations and rocky soils
Rocky foundations are the strongest. On such soils, strip monolithic and prefabricated reinforced concrete foundations are erected. Columnar supports with a grillage also perfectly serve as a reliable foundation for buildings on such soils.
Dense soils
Dense soils are formed from bonded rocks that can withstand heavy loads and are immune to heaving.
On dense soils, monolithic and prefabricated reinforced concrete foundations are mainly erected, and columnar foundation supports are also widely used. Dense soils are reliable and acceptable for all types of foundations.
The depth of soil freezing and the level of groundwater
These two factors determine the depth of the foundation. To create a reliable foundation for the structure, the depth of the foundation is determined below the freezing soil layers and below the groundwater level.
When building low-rise houses from lightweight structures, the foundation is made shallow above groundwater, but below the depth of soil freezing.
Guided by the calculated value of the load from the house on the entire supporting area of the foundation, the type of foundation, its dimensions and configuration are determined.
If several types of foundations can be applied to an object under construction, then the decision which foundation is best done based on the cost of its construction and reliability.
The main types of foundation foundations
Strip foundations
In terms of depth, strip foundations are shallow and deep foundations. Shallow tapes are used mainly in the construction of low-rise buildings from lightweight structures (foam blocks).
In other cases, foundation strips are laid below the water table, creating powerful base structures with high bearing capacity. Strip foundations are either reinforced concrete monolithic or strip made of precast concrete.
Strip monolithic reinforced concrete foundations
Monolithic reinforced concrete foundation is one of the most common types of foundations for buildings and structures. The device of such a supporting part of the house requires high costs for the production of earthen and reinforcement works, as well as for the installation and dismantling of the formwork. All this is justified by the great strength and high load-bearing capacity, which makes it possible to erect multi-storey buildings from heavy structures.
What is the best foundation to lay on dense soils? The solution to the issue, of course, will be made in favor of the construction of the strip foundation.
The question of which foundation is better for a house with a complex configuration of walls in the plan will also not raise doubts in favor of choosing a strip monolithic base.
Precast concrete strip foundation
Compared to monolithic belts, precast concrete blocks are more economical. Installation of precast concrete blocks does not require labor costs for the installation of formwork, work on reinforcement and concrete pouring of the foundation.
From prefabricated reinforced concrete blocks, both shallow and deep foundations are mounted. Precast concrete factories offer a wide range of precast foundation blocks.
What is the advantage of prefabricated blocks over a monolithic base? Installation of blocks does not require the production of time-consuming work on the installation and dismantling of the formwork, as well as on its reinforcement. The construction time of the base is significantly reduced due to the absence of time costs for concrete hardening. Reinforced concrete blocks are easy to transport and store.
Columnar foundations
Columnar supports are placed in the plan on the line of load-bearing walls, in the corners of the house perimeter, as well as in places where loads from various internal technical equipment of the house are concentrated.
Columnar supports can be shallow and deeply buried. Support pillars can be used instead of strip foundations. Supports are placed with a step of 1.5-2 meters. When comparing strip base with support pillars, the economy of the device of columnar supports is noticeable.
The savings lie in significantly less excavation and no formwork. However, one should not forget about the costs of installing a grillage. All doubts about the choice of the type of foundation will be resolved by a comparative technical and economic calculation.
Slab monolithic foundation
A monolithic reinforced concrete slab can act as an independent supporting structure of a building, and play the role of a pile foundation grillage.
Such structures are erected on soft soils. A reinforced concrete slab has a high bearing capacity, but is an economically expensive structure.
Piles
The main purpose of the piles is to transfer the load from the building through weak soils on denser soil layers.
The most common types of piles:
- Reinforced concrete piles;
- Bored supports;
- Casing;
- Shell piles;
- Metal screw supports;
- Wooden supports.
Reinforced concrete piles
Reinforced concrete piles are manufactured at the plant. The markings for the installation of piles are made on the bearing lines of the load-bearing walls, in the corners of the structure and in places where vertical loads are concentrated. Reinforced concrete supports are installed using piling equipment.
Bored piles
Reinforced concrete pipes are installed in drilled holes. Reinforcement cages are installed inside the pipes. Then it is poured with concrete with layer-by-layer compaction. Bored piles are used in densely built-up areas. In such places, the pile driver can cause unwanted deformations in the bearing layers of the soil. All this can adversely affect the foundations of nearby buildings and structures.
Bored piles are mainly used in industrial construction.
Casing pipes and shell piles
Casing pipes and shell piles are used in the construction of large industrial facilities. Installation and assembly of supports of this type is possible with the use of high-tech equipment.
Screw piles
Screw piles came to civil engineering in the second half of the last century from the military industrial sphere. For the rapid formation of a reliable base for small structures, they are indispensable. Developers use screw piles not only on soft clay soils, but also on dense soils.
Small screw supports are installed by two people by rotating the pipe using a lever. A lever in the form of a pipe is threaded through a hole in the upper part of the support and, by the efforts of two workers, a rotational translational vertical movement is given to the pile.
Watch a video detailing the pros and cons of screw bases.
The pile foundation is prepared in 5-7 days, depending on the size of the construction field.
Wooden supports
Wooden poles with pointed ends are driven into the ground with a hand tool or a copra. Most often, wooden piles are used in the construction of light outbuildings.
Before you start building a house with your own hands, you should ask the owners of neighboring houses about the foundation structures of their buildings. Such information will help you make the best choice of foundation for your home.
Strip foundations for a private house are most often made monolithic from concrete or prefabricated, from special large-format foundation blocks of the FBS brand.
Monolithic foundations are the most time consuming and expensive strip foundations.
Disadvantages of foundations from FBS blocks
Prefabricated foundations made of FBS foundation blocks do not require the device and disassembly of the formwork. Installed quickly. The foundation immediately after installation is ready for the erection of the walls of the house, since, unlike a monolithic one, it is not required to wait for the concrete to harden.
However, the large sizes of FBS blocks make the foundation device of them for a private house is not the most convenient and cheapest:
- For the installation of foundation blocks, it is necessary to use expensive lifting equipment.
- The height of the foundation has to be adjusted to the size of the block. For this reason, the foundation is almost always higher than necessary.
- Horizontal reinforcement in the seams of the masonry has to be performed at the wrong level where it is necessary, which requires an increase in the cross-section of the reinforcement.
- To fit long blocks under the relatively short foundation of a private house, you have to cut a lot of blocks, or make non-standard inserts in the foundation wall, for example, from bricks, which weaken the foundation.
- The standard width of the blocks also does not match well with the thickness of the walls of the house. The foundation wall is thicker than necessary.
The foundation of the FBS blocks turns out to be unnecessarily material-intensive, heavy and expensive.
The foundation is made of small-format blocks and bricks
In many cases, it is more practical and cheaper to lay out the foundation of the house by hand from small-format concrete blocks or bricks.
For laying the foundation of a house, concrete blocks (solid or hollow) are used, as well as solid expanded clay concrete wall blocks or bricks
Scheme of a cheap block strip foundation for a house. The foundation is suitable for the construction of a private house with walls of any material
Soil under the prefabricated block foundation
The groundwater level during seasonal fluctuations should not rise above the base of the foundation. At a high level of groundwater, it is better to use a strip foundation made of monolithic concrete.
The foundation of small-format masonry materials is suitable for building the foundation of a house on soils not heaving, weak and medium heaving.
If the soils on the site very heaving, then the foundation can be made provided that the soil is protected from freezing. Find out here at your site.
For laying the walls of the foundation, full-bodied concrete or expanded clay concrete blocks are used. These blocks have a fairly low water absorption, high frost resistance and the required compressive strength. For concrete blocks, these indicators are somewhat better than for blocks made of expanded clay concrete. The latter are lighter than concrete blocks.
Possible foundation laying of solid ceramic bricks. But this material for laying the foundation is now rarely used. The small size of the brick increases the labor intensity of the masonry. Generally brick foundation is more expensive than from concrete blocks.
Cheap strip foundation for home with basement
A cheap prefabricated strip foundation for a home with a basement can be made from hollow concrete blocks with vertical reinforcement of the basement walls
For foundation walls of a house with a basement, it is convenient to use
The presence of voids in the blocks makes it easy to perform vertical reinforcement of the foundation. Reinforced foundations are good for lateral loads. Vertical reinforcement option recommended for foundations with a basement. The vertical reinforcement rods are placed in the coaxial voids of the block masonry. Reinforcement voids are filled with B15 class concrete.
To support reinforced concrete basement floor slabs, a monolithic reinforced concrete belt must be made from expanded clay concrete and hollow concrete blocks along the top of the foundation walls.
A monolithic reinforced belt on top of the prefabricated foundation from any blocks should also be made for laying walls on them from blocks of aerated concrete (gas silicate) or porous ceramics.
In the walls of the basement, vertical reinforcement is made from hollow concrete blocks. For the device of a monolithic reinforced concrete belt (strapping beam), chute concrete blocks are used.
The monolithic foundation cushion is connected to the lower row of hollow blocks with reinforcement outlets. All voids in the bottom row of blocks are filled with concrete.
If the foundation is without a basement, then it is enough to fill the voids of the lower row of blocks with concrete, as well as to reinforce and fill with concrete vertical sections in the corners of the walls.
Sinuses of a foundation pit with a basement covered with soil from the outside only after the installation of floor slabs... Otherwise, under the action of the lateral pressure of the soil, the walls of the foundation may lead.
The prefabricated foundation for a house with or walls is laid in one layer. The foundation for the house is also made three-layer - a bearing layer, a layer of insulation and cladding. The facing layer is made of narrow (12 cm.) concrete blocks or solid ceramic bricks. The best cladding material is clinker bricks.
The thickness of the walls of the foundation is usually chosen the same as the thickness of the stone walls of the house. For a house with wooden or frame walls, the thickness of the foundation walls is made within 250 - 300 mm.
Block foundation for a house on highly heaving soils
To protect the house from deformations caused by the action of forces, the sole of the foundation is usually laid on. But there are others
Shallow insulated foundation for a house on heaving soil
A modern solution in houses without a basement on heaving soils- this is a device of a shallow heat-insulated strip foundation.
The idea behind this foundation is that the heaving soil near the foundation is protected from freezing and it ceases to heave in winter.
For this, the foundation and the soil around are insulated with a layer of foam or extruded polystyrene foam.
The construction of the bearing part of the insulated foundation made of masonry blocks can be performed as described below for the foundation of a house on slightly heaving soils.
How to insulate the foundation and soil in order to protect it from freezing is described in the article:
On not heaving, slightly heaving and even medium heaving soils shallow foundation for a private house can be made of masonry materials and without soil insulation.
Cheap foundation for a house on slightly heaving soils
On not heaving or slightly heaving soils, for a private house or a bath, suit For these conditions, it is enough to perform horizontal reinforcement of the rows of masonry.
The construction of the foundation made of masonry materials on slightly heaving and frost-protected soils: 1 - laying of the foundation; 2 - masonry basement; 3 - blind area; 4 5 - backfilling the floor on the ground; 6 - reinforcing masonry mesh every 20 cm. masonry;
The foundation masonry is reinforced with a masonry mesh with a wire diameter of 4-5 mm. and cell size 100x100 mm. Foundation sole width (size v in the figure) is calculated based on the bearing properties of the soil and the weight of the building -.
Foundation sole width for a house with light wood walls, or frame walls, for most weakly heaving soils, it is usually sufficient in the range of 20 - 40 cm.(the larger size applies to three-story buildings). For these houses, the width of the foot is made equal to the thickness of the foundation wall.
For stone houses with heavy walls made of bricks or blocks, the width of the base of the foundation on slightly heaving soils is increased to 0.6 - 0.8 m.(the larger size applies to three-storey houses with reinforced concrete ceilings). Here the foundation walls are thinner than the width of the foot.
If the width of the sole exceeds the thickness of the foundation walls, then the walls of the prefabricated foundation from the blocks are installed on and the tape of a monolithic reinforced concrete sole required width . A reinforcing cage is placed in the lower part of the sole before pouring concrete.
The bottom of the foundation trench is leveled by pouring a layer of sand and gravel mixture. On non-heaving and slightly heaving soils, the total thickness leveling sand pad no more than 200 mm. It is necessary to carefully compact the layer of bulk soil. The thinner the soil layer, the easier it is to tamp.
Polymer is placed on a sand cushion profiled membrane. The first row of blocks is laid on the membrane, on the masonry mortar.
If the walls of the house are made of aerated concrete blocks, then a monolithic reinforced belt must be made over the basement.
Cheap shallow foundation on medium heaving soils
On soils of medium heaving, in the construction of the foundation made of masonry materials add two monolithic reinforced concrete belts. One belt is a monolithic reinforced foundation sole. The second belt is arranged along the top of the foundation masonry or basement.
In addition, under the sole of the foundation they make anti-heap sand pillow.
Not buried foundation for a wooden or frame house or a bath on medium heaving soils: 1 - sand and gravel anti-heaving cushion; 8 - laying of the foundation and plinth; 10 - ground filling of the floor on the ground; 11 - monolithic reinforced concrete belt along the top of the base; 13 - monolithic reinforced concrete foundation base.
The thickness of the monolithic reinforced concrete belt at the top of the basement (11) and the foot (13) of the foundation 10 cm. In a monolithic belt, a reinforcement mesh with 2 or 3 bars of working reinforcement of class A-III, with a diameter of 10 mm.
The monolithic sole (13) is conveniently placed over the profiled membrane laid on the compacted sand cushion (1).
For light wood and frame houses it is dangerous to bury the foundation in the ground. The tangential forces of frost heaving of the soil act on the lateral surface of buried foundations. These forces may be enough to lift a light building up out of the ground.
For light timber and frame buildings an unburied foundation will be more economical and safer(in the picture above) . Due to the absence of a lateral surface buried in the ground, the tangential forces of frost heaving of the soil do not act on such a foundation.
Shallow block foundation for a house with stone walls
Shallow strip foundation for a house with stone walls on medium-grained soils. 1 - monolithic reinforced concrete basement base; 2 - filling the sinuses; 3 - sand and gravel anti-heaving cushion; 4 - reinforcing cage; 5 - blind area; 6 - backfilling the floor on the ground; 7 - horizontal waterproofing; 8 - house wall
The width of the basement of a house with stone walls is usually larger than the thickness of the walls. For these conditions, it is advantageous to make a monolithic reinforced strip of the sole of the prefabricated foundation of increased height. On top, on the bottom, lay out the underground and aboveground (basement) parts of the foundation made of small-format concrete blocks or bricks.
Pouring concrete with a monolithic basement sole directly into the trench, without formwork
On weak and medium-grained soils, it is advantageous to make the width of the trench equal to the width of the base of the foundation. Concrete is poured into the trench at the edge, without formwork. Previously, a reinforcing cage is installed in the trench. This method is suitable for sufficiently dense soils in which the vertical walls of the trenches do not crumble.
On medium-grained soils on the walls of the trench fix sheets of insulation, extruded polystyrene foam with a thickness of 40 mm. A layer of insulation separates the concrete from the ground, which reduces the impact on the walls of the foundation of the tangential forces of frost heaving of the soil. This solution allows you to refuse backfilling the sinuses of the foundation trenches. In addition, the insulation increases the resistance to heat transfer of the basement of the building and reduces freezing of the soil under the base of the foundation. The insulation layer also serves as a foundation waterproofing.
For a house with stone walls, in areas without a strong slope, the bottom of the foundation it is enough to deepen by 0.3-0.4 m from the surface of the earth.
Commentary on the video. When pouring concrete directly into the trench, the monolithic foundation strip can be left without waterproofing. Lining the trench with foil, as some do, is not necessary. In this version, the waterproofing is arranged above, at the level of the masonry of the basement blocks. The protective layer of concrete between the soil and the reinforcement in the base of the foundation must be at least 70 mm.
The height of the base during construction in areas with high snow cover must be increased. For the masonry of a high basement, it is advantageous to use concrete or lightweight aggregate concrete small-format blocks. Outside, the masonry is insulated with sheets of extruded polystyrene foam. When constructing a foundation on heaving soils, a layer of insulation is also laid under the blind area.
Sand pad for precast block foundation
A pillow of non-heaving sandy soil is always arranged under the foundation tape. On not heaving and slightly heaving soils, sandy the pillow serves as a leveling layer.
When constructing a foundation on medium and more heaving soils, sandy the pillow is already anti-tubercle. The pillow increases the bearing capacity and reduces the heaving deformations of the underlying soil.
To reduce the effect of the forces of frost heaving, under the foundation, they arrange an anti-heap sand and gravel cushion. The height of the sand cushion (size h in the figure) For most medium heaving soils, the thickness of the sand cushion is in the range of 0.3-0.5 m. The sand-gravel mixture is laid in layers no more than 20 cm. Each layer is carefully tamped.
For a non-buried foundation (in the figure), the thickness of the anti-heaving cushion is increased on medium heaving soils to 0.6 m. The width of the sand cushion should be wider than the sole of the foundation (size b) at least 200 mm. from each side.
Prefabricated shallow block foundation made of concrete blocks with increased base width
The width of the monolithic sole of the foundation (size b in the figure) The width of the foot may be greater than the thickness of the foundation wall.
Precast foundation waterproofing
Profiled membrane under the foot of the foundation
The profiled membrane under the sole of the foundation of a private house serves as waterproofing, and also through the protrusions strengthens the connection of the foundation tape with the sand cushion
A profiled membrane is a high-density polyethylene (HDPE) sheet with projections molded on the surface (usually spherical or frustoconical) with a height of 7 to 20 mm. The material is produced with a density from 400 to 1000 g / m 2 and comes in rolls from 0.5 to 3.0 width m, length 20 m.
Due to the textured surface, the profiled membrane is securely fixed in the sandy base, without deforming or shifting during installation. Anchored into a sandy base, the profiled membrane provides a solid surface suitable for placing blocks and concrete.
Profiled membrane serves as waterproofing, preventing the suction of capillary moisture from the soil into the foundation tape. On top of the membrane, foundation blocks are laid on the layer of mortar or concrete is poured with a monolithic sole. The membrane protrusions from the bottom side are pressed into the sand cushion, and from above, through the masonry mortar or concrete, they are fixed in the foundation strip. Thus, the membrane strengthens the bond between the pillow and the foundation.
Previously, a different method was used for these purposes. A layer of crushed stone was rammed into the sand cushion, which was then poured with molten bitumen. In modern construction practice it is easier and faster to roll out a roll of a profiled membrane on top of a sand cushion.
For waterproofing the side surfaces of the foundation of a house without a basement it is enough to use coating waterproofing. Before applying the mastic, fill it with a solution and level the masonry seams. Bitumen-based mastic is applied in two layers to the height of the backfill with soil. From the outside - to the level of the blind area. From the inside - up to the floor level on the ground.
Horizontal waterproofing of walls in two levels
Horizontal waterproofing of masonry is arranged from roll materials on a leveled base. It is recommended to arrange horizontal waterproofing in two levels.
The first layer of waterproofing is laid between the foundation and the plinth at the level of the blind area. This layer is connected to the vertical waterproofing of the foundation strip.
The second layer of waterproofing in the wall is made higher, between the basement and the wall of the house, at the floor level of the first floor. The waterproofing of the floor along the ground is connected to the waterproofing of the wall.
Shallow foundation water protection
Starting the construction of a private house on the site, it is necessary to choose the correct vertical landing of the house - to determine at what height to place the floor level of the first floor (basement height) and how to change the vertical layout of the soil on the construction site.
Correct planting of the house and vertical layout of the site are necessary to solve the following tasks:
- Ensure the location of pits, trenches, cushions and foundations above the groundwater level.
- Drainage of storm and flood waters from the house and further outside the site.
- Placement of above-foundation structures (walls, basement floors) above the level of the snow cover to protect them from moisture.
On construction sites, both with a slope and without a slope, it is always necessary to provide for and artificially raise the level of the ground, by filling (embankment) of third-party soil. Before starting work, make a vertical layout of the site in order to drain atmospheric water from the built-up area.
Read:
During the installation of the foundation, melt and rain water can accumulate in the trenches. Building a house on weakened soil saturated with water is fraught with cracks in the walls.
The process of erecting the foundation, from digging trenches to backfilling the sinuses and arranging the blind area, must be performed in dry weather and at minimum time.
Backfilling of the sinuses of the foundation is not performed heaving soil with layer-by-layer sealing.
After finishing work on the foundation, be sure to without delay make a blind area. I recommend making drainage trays along the edge of the blind area. Drain water from trays and from the roof drainage system away from the house.
Foundation waterproofing and water protection for a home with a basement
Foundation walls in a basement house require enhanced moisture protection. For conditions when the groundwater level is below the base of the foundation, a coating waterproofing is applied to the surface of the walls in the form of a layer of polymer-bitumen mastic.
The outer walls of the basement are additionally pasted over with two layers of waterproofing roll material.
The profiled membrane is convenient and profitable to use for waterproofing the basement floor. There is no need to make a concrete base for gluing waterproofing.
Only wall drainage can provide reliable protection of the basement from water. Be sure to do it.
Wall drainage around the foundation will reliably protect the basement of the house from water
Reinforcement of the precast foundation
To increase strength, into the walls of the foundation from any blocks you can lay the reinforcement in the horizontal joints of the masonry.
Reinforcement meshes of 2 - 3 longitudinal bars of working reinforcement with a diameter of 10 - 12 are laid in monolithic belts and soles of the foundation mm.
Reinforcement scheme for monolithic sections of the foundation. a - reinforcing mesh with two rods of working reinforcement; b - the same, but with three rods. 1 - longitudinal bars of working reinforcement A-III, diameter 10-12 mm; 2 - auxiliary armature BP-I, 4mm in diameter.
In monolithic foundation strips, the distance between adjacent bars of working reinforcement should not be more than 300 mm. If necessary, the number of rods is increased.
In the mesh of a monolithic tape with an increased width of the sole, they are installed across with a step of 600 mm additional bars of working reinforcement. Vertical working rods with the same pitch are placed between the lower and upper grids.
The protective layer of concrete between the soil and reinforcement in the foundations must be at least 50-70 mm.
Reinforcement scheme for a monolithic belt of a prefabricated foundation
Longitudinal and transverse reinforcement are fastened with knitting wire.
Don't leave your foundation unprotected for the winter
Protection from water and insulation for the winter of a strip prefabricated foundation made of concrete blocks. 1 - from top to bottom: surcharge soil layer, film, insulation (polystyrene, straw bags, sawdust), soil waterproofing and foundation tapes; 2 - waterproofing and insulation of the foundation according to the project; 3 - backfilling of the sinuses and embankment of the foundation strip with soil.
Shallowly buried foundations are not allowed to be left unloaded for the winter if the walls and roof were not made in time. This is especially true for foundations on heaving and waterproof soils.
On the lateral surface of foundations buried in the ground, tangential forces of frost heaving of the soil act, which will push the unloaded foundation up.
Under unprotected foundation tape the soil will freeze to a great depth, while significantly increasing its volume. In the spring, having begun to thaw, the soil will sag unevenly, the foundation will not be able to sink to its original place. All these processes often lead to cracking of the foundation.
If such a foundation is left unloaded for the winter - the house is not built, then the foundation and soil near the foundation must be protected from water and freezing... The foundation and the ground are insulated, covered with heat-insulating material - foam, sawdust, straw, etc.
It is safer and more profitable to entrust the choice of a specific foundation design for a house to specialists. Independent decision most likely will lead to an excessive rise in cost construction as a result of reinsurance, or to the weakness of the structure, which will cost even more.
Blocks. FBS. Concrete. Expanded clay concrete. ASG. Insulation plates. Foundation. Profiled geomembrane. Waterproofing. Armature. Drainage. House. Instruments
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The choice of a foundation for a house is based on determining the degree of its reliability, the ability to withstand a certain load, the possibility of building a foundation on a specific soil with a known level of groundwater occurrence.
Of course, an important aspect when choosing is the amount of material resources that have to be spent on carrying out the work and the ability to perform all the manipulations without involving special equipment.
When choosing a foundation for a future home, you need to pay attention to simple and most reliable structures, the construction of which can be done by hand, without the help of specialists. The most economical but reliable are:
- columnar;
- tape.
Which one of existing species grounds are suitable for construction, the homeowner decides, but the most popular is a columnar foundation. This is a system of pillars installed not only at the corners of the house, but at all intersections of walls and partitions.
Features of a columnar foundation
Base post construction
A simple and reliable columnar foundation can be made with your own hands when erecting a building on any soil. It differs not only in the simplicity of the work, but also in its rather low cost. The material that will be required in order to make such a foundation may be:
- brick or concrete;
- natural stone or concrete blocks;
- rubble concrete or quarry-flagstone.
The beginning of work is the clearing of the area defined for the foundation. If there are bumps or pits on the surface, then it must be leveled by removing some layer of soil or sprinkling it with sand and gravel. Having checked the quality of the preparatory work carried out using the hydro level, you can make a markup of the future foundation.
Layout begins by defining angles and diagonals. Having installed the pegs in the corners and pulling the lace, you need to make sure that the foundation is in the correct geometric shape, which is to be erected. Now, at the corners and at the intersections of the walls, you need to dig holes. Their depth depends on the level of groundwater and soil freezing, but cannot be less than 50 centimeters. The width should be such as not to hinder the work of laying bricks or blocks.
At the bottom of each prepared pit, a sand cushion is made with a thickness of at least 10-15 centimeters, spilled with water and rammed, and in the middle, a rod of reinforcement is driven in, which will become a fastening element when erecting a pillar.
Construction of pillars
The thickness of each pillar should be 12 centimeters greater than the thickness of the future walls. At lung construction house, the number of pillars may be small, but when erecting a brick building, the distance between the foundation pillars should not exceed 2 meters. Having decided on the number of pillars, having prepared a sand cushion and installing the rods, you can proceed to the beginning of the masonry. The rods, the height of which necessarily exceeds the height of the pillar itself, are cut off with the help of a grinder at the end of the masonry. It is necessary to make such pillars that will rise above the soil level by at least two bricks, process them with bitumen or other waterproofing material and cover them with earth. From above, the erected foundation supports are also covered with waterproofing.
Another, no less simple and reliable way to build a support for a columnar foundation is to fill the pillars. To do this, you will need to drill wells about two meters deep along the entire perimeter of the base, and the corners and intersections of future walls, according to the marking. The hole must be such that an asbestos-cement pipe with a diameter of 25 cm can freely enter it. Having installed the pipes in the holes of the finished wells, it is necessary to check the diagonals again. Now is the time to take care of the reinforcement. The fittings are installed inside each pipe. Watch the video, what makes the flood posts good when building a foundation.
After pouring the solution into the pipe, it should be slightly raised and the composition should be allowed to flow out onto the sand cushion. This is necessary to get a kind of platform. When installing the pipe, it is necessary to check its verticality and fix it in the desired position. For fixing, you can use only coarse sand, but never waste soil. Concrete is poured into the pipes gradually, constantly bayoning the solution to avoid the formation of voids.
Wall connecting the pillars
Pick-up structure
The main disadvantage of the columnar foundation is the absence of a basement, which would become a reliable protection of the house from rodents, help preserve heat and prevent moisture from entering the living space.
In order to provide the building with additional protection and successfully replace the missing plinth, it is necessary to build a so-called pick-up. This is the easiest way to replace the base. It can be made from brick, rubble stone, concrete.
When carrying out construction on sandy soil, the pick-up must be deepened into the ground by at least 20 centimeters. Equip a 15 cm thick sand cushion and refuse to tie the wall to the posts to avoid cracking due to uneven shrinkage.
Trying to avoid unnecessary material costs, pick-up can be done using DSP. The arrangement of a columnar foundation has a number of limitations, including a high level of groundwater occurrence. In a certain situation, a belt foundation will be no less simple and reliable, which can be made independently, without the involvement of specialists and the use of construction equipment.
Strip foundation
The strip foundation is distinguished by high strength and durability, but much more concrete is spent on its construction. There are two options for the construction of such a foundation:
- monolithic;
- made.
For the installation of a prefabricated structure, several components made of reinforced concrete will be required, and in the manufacture monolithic foundation you need to make a number of reinforcing elements that are poured with concrete. Watch a video on how to build a strip foundation with your own hands.
In order to make a solid and reliable strip foundation, after completing the usual preparatory work on the construction site, it will require digging trenches with a depth of at least 50-70 centimeters.
Important! The depth of the trench must exceed the depth of the soil freezing.
At the bottom, equip them with a sand pillow, which, as with other methods of constructing the base of the house, spill with water and tamp. Now the formwork should be erected, the height of which corresponds to the height of the future foundation. A thin layer of concrete is poured at the bottom of the trenches and reinforced structures made of rods with a diameter of 10-12 mm are laid on it. Concrete can be poured without erecting formwork, but in this case, after pouring the trench, it will be necessary to make several rows of masonry using concrete blocks or bricks.
Choosing the simplest, strong and reliable foundation for your future home, it is worth clarifying the amount of material required to perform the work, the need to use special equipment and the amount of material costs. Preliminary calculations will help you understand which of the proposed foundation options will be the simplest, most affordable and reliable.
In the aggregate of the price of a building structure, so important for any construction, there are many data that you need to know in order to install a cheap one with your own hands.
When designing a building, all the nuances of climatic conditions, the soil condition under the house, to what depth the base of the structure can be installed are taken into account.
Spring observation of soil merits allows to evaluate:
- sandy
- stony
- mixed
On such areas, it is possible to lay buildings on any basis, the calculation of costs is carried out depending on the choice of its type. Problems will be delivered by an area with clay soil.
Clay is capable of absorbing liquid with deep freezing, from which soil heaving occurs.
To get rid of this, it is necessary to lay the foundation at a depth with additional costs.
All options are possible when a new construction is started and there are ways to determine if a restructuring is being carried out or if you need a cheap foundation with your own hands for a garage, a bathhouse, a gazebo, then they are guided by the structure being erected, its volume and the amount of expected load forces acting on the base.
In any case, it is necessary to know the soil properties of the site, the conditions of deep freezing, the existence of operating underground springs.
The existence of a large number of varieties of laid foundations under buildings has not been canceled, but they are all created on the main types:
- columnar
- tape
- tiled
The columnar version speaks for itself in the name, it is laid out with uniformity along the perimeter of a brick building, in the form of columnar structures. The base under the structure of the pillars is considered cheap and simple, even residential buildings are erected above it, if the walls are light frame, wooden.
Such a foundation was not widely used only because cellars cannot be made in houses and careful insulation of the created space is needed. Outbuildings with pillar bases are the most convenient and economical case.
Old buildings were mainly built on strip foundations, they are:
- shallow
- deep-seated
They are still being erected over such a foundation, it has not lost its relevance.
Shallow deepening is carried out if the soil does not heave and it is possible to lay a tape at a depth of 0.7 m with a 30 cm sand cushion in a low-rise building.
A reliable and durable strip foundation is if the line is laid deep. This method is used in any construction, regardless of soil properties.
A tape line with a large support area is capable of withstanding multi-storey buildings; reinforced concrete, brick or any suitable one is used for the construction.
With this type of foundation, it is possible to build good basements, but this is not an option to reduce construction costs. The foundation requires the cost of earth and concrete actions, the volume of which is quite large.
Any problem soil, even peaty and clayey, is able to withstand home ownership with a tiled foundation.
Arrange them with a shallow depth on a pillow made of sand and gravel. The slab is made of reinforced concrete according to the size of the building, it is not afraid of soil changes due to seasonal movements.
What materials do they save on?
The choice of the type of bases lies with the developer, experts will help to add up their lowest cost without compromising quality.
The value is determined from the total result of the costs incurred:
- geological studies of soil
- design
- purchase, transportation of building materials
- excavation
- execution of reinforcement and formwork operations for the arrangement
- wages for workers, subject to the construction of a hired force
If it is not possible, remove some item from the above in order to reduce the cost of the foundation building, they find optimal solution in choosing less expensive alternative materials. The use of sand and cement, as the most expensive components in supporting structures, is not recommended to be replaced with low-quality ones.
Instead of cutting solid reinforcement, old scrap metal may be suitable, consisting of:
- squares
- unusable metal products
- channels
- fittings
- wire pieces
- twigs
They use construction waste, rubble stone, brick fragments, replacing crushed stone.
Digging trenches for laying the base line is carried out in strict accordance with the design requirements, it depends on the geological resolution regarding the condition of the soil on the site.
Performing a box for formwork, concrete pouring will be made into it, you can make a choice from the details:
- metal
- wooden
- plastic
The best option would be to make a wooden product using trim boards. The inside is lined with cardboard or fiberboard pieces. Even having put together a formwork box from good boards, it can be used more than once in other buildings.
Budget savings options
Reducing the labor intensity of some processes, in the device of the strip foundation, accepting the replacement of deep laying with a shallow depression, they make it possible to install a foundation equal to the traditional one in terms of its reliability.
For this, a partial soil change is carried out with a pillow from, so that it gives a guarantee of fundamental deformation in permissible dimensions. When laying a tape with a small depression, you can even arrange small basements and cellars on any soil except too heaving.
Construction consists of stages:
- digging a trench line with a design depth of up to 0.7 m
- lay an anti-heave cushion of coarse sand equal to 0.2 m in the upper layer, in the lower one mixes sand with crushed stone 0.1 m high
- carry out a thorough compaction of the layers
- covered with a polymer film so that it does not penetrate into the rammed base
- mount formwork panels, attach roofing sheets that prevent leakage concrete mix through the cracks, save the lumber for easy disassembly for use at another time
You should be aware of the need to load the foundation before winter; it is not recommended to leave it free of walls for a cold period.
Pile foundations
The next foundation for the structure is pile foundations:
- bored
- pile-screw
Designers determine the places for drilling wells, in which a frame made of metal reinforcement is mounted and concrete is poured. Wells are reinforced with roofing felt lining, casing, they are taken out after the solution has solidified, for those wishing to increase the pile strength, they are not touched.
Pile holes are drilled using technical devices or simply by hand using the well-known TISE technology. Its feature is the excellent design of the pillars widened at the base, which increases the support area and the ability to resist soil buckling forces.
A hand drill is used to gouge wells.
Built into it:
- sliding bar
- folding plow
- operated cord
The plow's own weight lowers it, holds it with a two-link locking mechanism, and can be lifted to a vertical position with a cord. A locking screw is used to fix the extension of the rod to different lengths.
In the process of drilling, the plow is removed, rotary movements are carried out with a drill, and, as necessary, it is raised on to clear the adhering earth.
With the help of a plow, the lower part in the borehole is expanded, each time drilling continues with a change in the direction of rotation. The hole is filled with reinforcing cage, concrete mortar. A roofing shirt is placed in the resulting cylinder, which protects against destruction acting on the column of soil forces.
Completion in the creation of a pile is the laying of a grillage in the form of a reinforced concrete or metal beam. Its task is to provide a coherent whole of all foundation parts so that the expected loads are evenly distributed across all installed piles.
The grillage is installed both high and low, it is above or below the ground. At the same time, a single bundle of a house with annexes is excluded, for them an individual base is taken out, which is separated by expansion joints.
Such actions are necessary due to the difference in load forces. The walls from the building press on the foundation areas in different amounts compared to the porch or terrace. Printed bases under buildings can be erected and can withstand not only light wood or frame houses, as well as block, stone.
For them, groundwater, unreliable soil are not dangerous, there were practically no drawbacks from the consequences of exploitation. Driven pile structures deep into the ground, in accordance with the level of its freezing, below this mark, will protect it from freezing soil vibrations.
What are screw structures
Builders find it economical to erect foundations using screw piles. Earthwork takes a lot of time and labor, their cost is not considered insignificant, especially if heavy equipment is used.
Installation screw piles manage with less material costs compared to a tape or tile base. Steel pipes are used to make them.
Constructive forms are cutting blades screwed into the soil, regardless of the projected depth. A part is welded to the top, on which the grillage is fixed.
If the soil has a heterogeneous composition, the piles are screwed in unevenly, the deepening is carried out, if necessary, with the leveling of the above-ground parts.
The screw method of installing the bases is suitable for all types of buildings, but stone and block houses allow in the foundation, in addition to installing the grillage, also the installation of a monolithic slab serving as a subfloor. The implementation of pile-screw foundations is carried out regardless of the change of season.
What attracts a shallow base
Private developers most often use shallow foundations. They are somewhat cheaper, they also propose to combine a regular tape with insulation by installing a plate.
For this, the base is minimally leveled by the production of a sand cushion, and it is insulated with extruded polystyrene foam, eliminating the risk of frost heaving. The tape is made with a variable section, lighter and more stable.
Each site is calculated for monolithic and reinforced methods. A distinctive feature of such a foundation is an insulated blind area with a floor slab.
The actions are carried out as follows:
- remove the fertile layer
- dig a trench to a depth of 50 cm and a width of 1 m
- pour sand up to 15 cm and tamp
- install a formwork with a reinforcing cage
- carry out concrete pouring
The width of the strip sole is 60 cm with a height of 30 cm.
Warming is carried out, starting with an external compacted sand filling, a polystyrene foam plate with an inclined blind area is mounted on it. Use the excavated soil to reverse the inner foundation sides.
The surface cells obtained from the formed tape are leveled with sand, the insulation materials are mounted over the entire surface, reinforcement is carried out on top and poured with concrete mortar, obtaining a single monolith from a rigid structure. It is able to withstand structures of several floors.
The advantages of insulated slab foundations include:
- foundation tape and slab work in one piece
- an insulated monolith is obtained, which serves as a rough floor surface
It is necessary to pay attention to such a structure for developers seeking to reduce costs not only for, but also for the heating season, because the house will be warm in the cold season and cool in the hot season.
Points to be noted when building foundations:
- the pillar at the base can be with a constant cross-section in the form of a cylinder, a parallelepiped, as well as with a variable transverse, with an extended lower part
- the fence is carried out with a height of up to 30 cm, otherwise there will be poor underground ventilation
- composite reinforcement can reduce the cost of slab structures
- installation of non-buried products is carried out by half of the soil freezing
To make the base for the house the most reliable and of high quality, each homeowner seeks to reduce the cost of the work performed, while choosing the most optimal option for the soil, terrain and wallet.
The main task in foundation devices is to install a house on it for a long time, without further problems during its operation, for this you need to get acquainted with this responsible process, consult with specialists, so that the building will serve the joy of the developer.
The easiest and most reliable way to make a foundation is in the video:
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