Any professional builder will tell you that it is necessary to plan a basement in a house at the building design stage. This approach will significantly reduce costs and also reduce labor costs. It is good to have a basement in a private house, first of all, because it allows you to get additional meters of space that you can use at your discretion.
The basement in a house can be built in different ways. With a strip foundation, the basement will fully replicate the layout of the first floor. it can also be arbitrary, however, it is recommended to make it no less than 180-220 cm. With a high basement ceiling, it will be possible to make a living space from it, which in its characteristics will not be inferior to any room on the upper floors.
In addition, you should not completely bury the basement walls. 100-120 cm should be left above the ground. The height above the ground can be used to install windows and a ventilation system for the basement. If the basement is buried more than 150 cm, then the risk of flooding of the room during seasonal floods increases exponentially.
The construction of the basement must be carried out under the supervision of specialists. Especially if the underground room is planned to be built in an already finished house.
Construction method with preliminary digging of a pit
Before making a basement, you need to dig a foundation pit for it, that is, a hole that will exceed the dimensions of the basement by 30-50 cm on all sides. A sand and crushed stone cushion consisting of several successive layers of these materials is laid at the bottom of the excavated pit. Next, a reinforced concrete slab is installed. This slab will act as the foundation of the entire building.
Digging a pit using an excavator.
The upper part of this slab must be insulated from moisture penetration using rolled roofing felt (laying 2-3 layers is recommended for reliability). Next, a new concrete layer should be poured on top of the roofing felt, which will act as a base for constructing the walls of the basement.
Bricks, foam concrete blocks and other suitable building materials can be used to build walls. It depends on the design of your home. As soon as the construction of the walls is completed, they must be isolated from water penetration from the outside. For this, various waterproofing materials are used: roll insulators, bitumen mastics, etc.
Next, the basement is covered. As a rule, a monolithic slab is installed. Of course, at this stage other materials are also used for flooring (wood, concrete beams, etc.). Finally, the free cavities between the walls are filled with earth (with gravel).
It should be noted that this principle of basement construction has negative aspects:
- Construction requires the use of special equipment, which is often simply impossible in some areas located far from the city.
- Construction must proceed fairly quickly, because there is some risk that the walls of the pit will begin to crumble or float when the process is delayed.
- Brick and block walls cannot be called 100% airtight, because small cracks will form at the joints of the material, through which moisture penetrates;
- The installation of an effective waterproofing layer requires serious financial costs.
If you have chosen this technology to build a basement under your house with your own hands, then you need to take into account the fact that you won’t be able to do everything yourself - you will have to hire equipment and builders, which will lead to significant costs.
Method of pouring reinforced concrete walls into the ground
When using this technology, it is necessary to dig trenches in place of the basement walls, which serve as parts of the strip foundation. Their depth should be 150-200 meters, and their width should be 40-60 cm. If the basement of the building is reinforced concrete, then formwork must be installed above the ground level; if the base is supposed to be made of other materials, then no formwork is required.
Prepared trench.
Reinforcement is placed in the dug trench, after which it is filled with cement mortar. The result is a wall without a waterproofing layer, but its thickness provides a minimum level of hygroscopicity, so for groundwater this is a serious obstacle, but not impassable.
If you have chosen such a basement device, it would be correct to carry out drainage work. In this case, water coming from various sources will simply flow down the walls of the basement, going into the drainage channels. If concrete walls remain under constant influence of water for a long time and they do not have a waterproofing layer, then they will not be able to be used for a long time.
After the concrete has hardened, subsequent work can begin. In cases where the ceilings of the basement are supposed to be cast right there, it is necessary to install formwork, carry out reinforcement and install stiffeners.
Next, soil is excavated from the future basement to the level of its base. At the walls, the soil is slightly excavated under the walls (about ½ of their thickness). A sand cushion and gravel are laid at the bottom, after which the base of the basement is reinforced and cast with cement mortar.
Scheme of pouring concrete into a trench using waterproofing.
One of the main disadvantages of using this technology is digging a trench, reinforcing it and filling it with cement mortar. It is not always possible to correctly lay the reinforcement with your own hands, so it makes sense to hire workers for this purpose. All work must be completed quickly enough. The rest can be done with your own hands without the involvement of specialists.
Construction of a basement in an already finished house
It is quite difficult to make a basement in a cottage that has already been built earlier with your own hands. The construction of such premises must be carried out by professionals. The construction of a basement in the case of an already finished house must be motivated by something, because this is a very expensive undertaking. It should also be said that it is not so easy to make a basement in a finished house correctly. Even many contractors say that “we don’t do that.” This is due to the high labor intensity of the work. But, however, nothing is impossible.
In most cases, the cost of laying the foundation of a standard country house is about 20% of the total financial investment. If the foundation needs to be rebuilt (for example, to make a basement), the costs will increase by 2-3 times. That is why it is necessary to approach the issue of building a basement in an already finished house as responsibly as possible. In this case, experts recommend making a basement under part of the house, and not under the entire first floor. Economically it is more profitable. When choosing this technology, construction will proceed differently. The basement walls will not be connected to the walls in the house.
The following technology can be chosen: first of all, soil is removed to a depth of 150 cm along the perimeter of the walls of one of the premises of the house (for example, the kitchen). The floor and walls of the future underground structure are reinforced with asbestos cement sheets. Waterproofing is placed on these slabs in several layers. Finally, a reinforced concrete floor about 20 cm thick is poured, and small-width concrete walls with additional reinforcement are installed around the perimeter of the room.
Taking into account the fact that the thickness of the walls is small, it is necessary to install high-quality waterproofing. In general, any basement construction should be carried out taking into account the installation of a highly effective waterproofing layer, because underground rooms are most susceptible to moisture (ground and sedimentary water).
An option for installing a basement under part of the house.
Ventilation issue
Ventilation of basements is carried out, as a rule, using ventilation ducts. Ventilation ducts are made of brickwork with a certain cross-section or from other suitable materials (corrugations, plastic pipes, etc.).
The exhaust pipe is installed under the basement ceiling. Its upper part should extend onto the roof of the house and be located as high as possible. To improve the draft of the basement exhaust pipe, it is necessary to lay it in close proximity to the smoke ducts (for example, the duct of a heating boiler). The upper part of the supply pipe can be placed in the attic, and the lower part - under the basement floor. During the summer months, there is often a lack of natural draft, so many homeowners install a fan in the exhaust pipe.
In addition to ventilation ducts, ventilation of the basement can be done using vents, which can be presented in the form of small windows located in the basement wall. High humidity is eliminated by ventilation.
Blind area device
The blind area is the first barrier to the penetration of melt and rain water into the house. If there is no blind area around the country house, then during rains moisture will gradually seep to the walls of the room, after which it will penetrate into the basement through the capillaries in the building material. Due to constant exposure to moisture, the material will begin to quickly deteriorate (especially in winter, when water freezes and expands).
The construction of a blind area with your own hands is carried out using various materials: monolithic concrete, slabs, cobblestones, brick, asphalt, etc. Its width will depend on the soil and the length of the cornice. In the standard version it is 50-100 cm.
Doing it yourself in a country house is quite a complex and responsible task. In 95% of cases, it will not be possible to do without the help of specialists who can professionally make waterproofing and thermal insulation layers.
It is worth noting that making basements in already constructed buildings is not recommended, because this will cause high construction costs. In addition, the risks of damage to the building’s foundation will increase, especially if the construction of basements is done by hand.
If you decide to build everything yourself, be sure to enlist support. Even banal advice from neighbors who have already built basements in their houses and know everything about the groundwater level and the features of the area will help. Whenever possible, the construction of a basement should be carried out by hiring specialists.
As you know, our people are strong in hindsight. This statement fully applies to the situation when they first build a house, operate it, and then suddenly begin to realize that they were in vain not thinking about the basement.
And in fact, the basement under the house is a multifunctional room that allows you not only to store winter supplies, but also to store many seasonal items, garden tools, watering hoses, etc.
Of course, when the house is already built, you can’t dream of a large basement, since any excavation of the soil inside the existing foundation is extremely undesirable.
If this is a light summer house, standing almost on the ground, then the problem is not difficult to solve, but if the house is solid with heavy walls and roof, the problem becomes more complicated. In addition, it is not possible to dig a hole for a basement under every house. For example, if the foundation is a monolithic slab, then nothing will work.
The main advantage of this method of building a basement is the ability to do all the work yourself.
Among the disadvantages are the following:
- The need to carry out all work manually due to the impossibility of using technology.
- Soil is removed through living quarters, which is not very convenient for both workers and household members.
- Not everyone can correctly install ventilation and foundation, which in the future can make it difficult to use the basement for its intended purpose, as well as lead to dampness in it.
If it is possible to make a basement during the project, you should prefer this option. The room will be much larger in area and better equipped.
Anyone can build a small basement
Basement - This is the best option for increasing the usable area of the building. In an apartment building, it is mainly used to accommodate communication networks. In a small private house (dacha or cottage), the underground space can be used as an underground garage, laundry room, boiler room, or equipped with a swimming pool or gym. The entrance to it can be made both from the ground floor and from the street.
Design features of underground premises
A basement under a private house can be implemented in several ways. The best thing basement arrangementat the dacha, plan during design. This will allow you to take into account all the features of the building and geodetic conditions.
Also, it is worth considering its location:
- basement under part of the house;
- a basement under the entire area of the house, as is done in an apartment building (for example, with a strip type, it will completely coincide with the configuration of the first floor).
It is worth considering in advance how the foundation will be laid. You can use the method with preliminary creation of a pit or pour reinforced concrete walls.
A high-quality basement laid at the start of construction is a reliable foundation for the house
Planning stage
When starting design, you need to clearly know why the basement is being built in the house. The underground room that will be used as a living room must have a certain height. In this case, it is recommended to comply with the minimum standard values - at least 2.5-3 m, like a regular residential floor.
If the basement in the building will be used more as a technical room (for example, a boiler room or cellar), a height of 1.8 - 2.2 m will be sufficient.The depth of the pit, in turn, should be equal to the height of the room + 0.5-1 m. The reserve will be spent on floor screed and ceiling finishing.
A cellar is an appropriately equipped recess in the ground that can be built on a site near a house, in a garage or in a basement. I believe that entering the underground storage facility from home is the best option. The cellar in the courtyard of the house needs to be insulated and heavily waterproofed, and this is an expensive and labor-intensive process. I built a cellar under the house with my own hands, digging a pit in the basement, the whole process took one summer, the construction was inexpensive in terms of money - about 10,000 rubles for everything.
The depth of the cellar and the choice of flooring material depend on the groundwater level in your area. It is better to build in dry weather in the summer, when the water does not rise high.
How to build a cellar in the basement of a private house
Before starting work, think about where and how you will remove the excavated soil. If you provide a cellar at the stage of building a house, these problems will not affect you. You should also remember about the strength of the building, so dig the pit as close to the center of the house as possible, otherwise the foundation may sag.
The exception is a foundation on piles, which cannot be damaged because the load will be on the deep layers of the soil.
Digging a pit
The height of the cellar should be sufficient so as not to bend to death in it. Dig an oblong pit to comfortably accommodate the stairs, and a little more than the planned area, taking into account waterproofing. You can dig the hole yourself or hire a digger, as digging is more difficult than it might seem.
When the preparatory work is completed, you can proceed to arranging the cellar.
Filling the floor
We will concrete the floor. Concrete does not protect the room from moisture 100%, but it is the best solution for implementing it yourself. The concrete coating will not allow anaerobic bacteria, rodents and other pests to enter the room, and during high water there will be no standing water in the cellar.
- Level the bottom of the pit.
- Add a 20cm layer of sand and compact it until the surface becomes hard.
- Place a layer of gravel on top, tamp it down and level it.
- We overlap the roofing felt on the finished pillow. This must be done so that water does not seep out from below, and the concrete does not soak into the soil when pouring.
- For reliability, we reinforce the floor with rods with a diameter of more than 5 mm.
- Pour 10 cm of concrete and let it dry. For complete hardening, at least three to four weeks should pass; during this time, do not lower yourself into the pit so as not to disturb the coating.
Covering the walls
The walls can be made of brick, foam blocks or reinforced concrete. I chose concrete grade M200, you can use a more durable material. Arranging a cellar with reinforced concrete walls:
- We install a mesh of reinforcement. It is best to take special rods with a cross section of 10-15 mm. If there is no suitable fittings, you can connect two thin rods or take pipe scraps. We connect the rods into a mesh with wire.
- For vertical formwork we use available materials: sheets of plywood, chipboard, slab, etc. If there is nothing to make formwork for the entire perimeter, the boards can be moved as work on the wall section is completed.
- You can add a little mortar and crushed stone to the concrete. Pour the concrete in layers of 20-30 cm, compact it and let it harden. The height of the wall should reach the ceiling.
Making an overlap
It is easier to make a ceiling for a cellar in a house than for one located in the yard, but you cannot do without it. The purpose of the ceiling in our case is to protect against heat, since the temperature in the cellar must be maintained at up to +5 degrees. After installing the stairs and planning the entrance to the cellar, we will make a wooden floor.
- We install beams on the floor and lay boards on them. Securely attach with nails or self-tapping screws.
- We lay a film on the boards for waterproofing.
- We carefully cover the entire surface with mineral wool or glass wool.
- We overlap the thermal insulation layer with a roll of waterproofing material. We seal the seams with construction tape.
- We lay the covering that will be directly under the floor.
- The top layer is the same as the floor in the room where you dug the pit. I installed a cellar in the basement, so I covered the floor with linoleum, leaving room for a hatch.
How to avoid dampness
Even the best waterproofing will not protect the cellar from dampness with a full guarantee. Condensation may form on the walls due to the proximity of groundwater, and vegetables also release moisture.
Ventilation is not difficult to arrange - for a large cellar you will need two pipes, for a small one one is enough. Any pipes will do; I used PVC sewer pipes. The area of my cellar is only 5 sq.m. I made do with one outlet for air supply and exhaust. For a large cellar, it is advisable to equip more serious ventilation with forced pumping of air from the underground.
It is advisable to install the hood on the roof of the house, and place the lower part of the pipe under the ceiling of the cellar. The pipe for air supply to the room should be at a height of up to 30 cm from the floor, with the other end out of the nearest window. To prevent insects and debris from getting into the supply pipe, install a mesh on it. It is advisable to equip the hood with a deflector to enhance draft.
Instead of a conclusion
As you can see, building a basement with your own hands is not at all difficult. The main thing is to find the right time and finish the job!
Your own cellar will be useful in almost every private household. You can store vegetables, canned goods and other things in the cellar. At the same time, such storage will be as convenient and high-quality as possible, because the cellar is located underground and does not take up useful space in living quarters, and the temperature conditions in the basement ensure the longest possible storage of various food products.
The cellar can be equipped both at the stage of construction of the building, and in an already finished private building. In the second case, the work is complicated by the fact that you will have to dig a hole for the cellar by hand and remove the soil from the room yourself. Otherwise, the procedure for arranging a cellar for both mentioned situations is practically the same.
The cellar in the basement of the house must be buried at least 150-180 cm deep. With less depth, the temperature in the basement will exceed +8 degrees, which will not have the best effect on the conditions and shelf life of vegetables.
Before starting work, you need to establish the depth of groundwater passage specifically in your area. This is easiest to do at the stage of arranging the foundation of the house, because... Geodetic research is included in the list of mandatory preparatory activities.
If the house has already been built, but you have just now decided to start arranging your personal cellar, determine the point of passage of groundwater you'll have to do it yourself.
This can be done according to the following methods:
- dig a hole with a depth of 250 cm and monitor its condition for several days in terms of filling with water;
- determine the depth of water in wells on adjacent land plots.
You can also contact a specialized company engaged in drilling wells.
Checking the groundwater level should be done during spring floods or prolonged autumn rains. It is during these periods that groundwater aquifers rise to their maximum level.
If groundwater is closer to the soil surface than 100 cm, you will have to refrain from constructing an underground basement, giving preference to an external cellar in some other suitable area.
If the groundwater level is within 100-150 cm, you can try to reduce it using a drainage system laid around the perimeter of the building below the floor of the future basement. In this case, special attention will need to be paid to waterproofing the basement walls.
Ideally, an underground cellar should have a depth of 200-230 cm. With such depth indicators in the underground room, it will be comfortable to go about your business, and the air temperature will be set at approximately +4-5 degrees, which is the optimal indicator for long-term storage of canned food, vegetables, etc.
Before you start arranging the cellar, you need to select suitable building materials. The walls of the room can be erected from concrete, natural stone, concrete blocks, ceramic bricks. It is better not to use sand-lime brick and cinder blocks.
Determine the best option for entering the cellar. The simplest option is to install a hatch in the floor of the room with the installation of a ladder to descend into the cellar. If possible, the descent can be made of full-fledged concrete steps - this is more convenient. An inclined trench for arranging the descent must be provided at the stage of digging the foundation pit.
Step-by-step guide to building a cellar
Self-arrangement of the cellar under the house is carried out in several simple steps. Complete each of them in sequence.
Video - Cellar under the house
The first stage is determining the dimensions
Start by determining the dimensions of the cellar that are convenient for you. As a rule, the cellar area under the house is at least 5-8 m2. With similar dimensions, it will be possible to place racks with canned food in jars and containers with various root vegetables. For the rest, be guided by your needs.
Make the size of the pit at least 60 cm larger than the size of the cellar on each side. Of this reserve, approximately 30 cm will go to the walls. The rest of the space will be filled with waterproofing material and a clay castle.
Video - Construction of a cellar
Stage two – excavation work
Start digging a pit. If the house is just being built, use special equipment. In the case of arranging a cellar in an already finished house, you will have to dig it manually. To prevent the side walls of the pit from crumbling, strengthen them with temporary supports, for example, made of plywood or boards.
Make the depth of the pit such that its bottom is approximately 30 cm below the bottom of the future cellar under the house.
The third stage is the foundation
Fill the bottom of the pit with mixed grade crushed stone. Compact the backfill and lay the reinforcing mesh on it. Pour the concrete. Allow the fill 2-5 days to dry initially. After this, you can begin arranging the walls of the future cellar.
Stage four - walls
It is better if the walls of the cellar are made of monolithic concrete. To increase the moisture resistance of the fill, it is necessary to add a special mixture to the solution to create penetrating moisture insulation.
Assemble the formwork for pouring the concrete walls. To do this, use boards, bars, ties and nails. It is better that the formwork boards are planed - they are easier to dismantle in the future. Make the formwork about 30 cm wide. Lay 2 reinforcing bars along the future walls with a connection at the joints of the walls. Use soft wire to connect the rods.
At the stage of arranging the formwork, provide places for placing ventilation pipes.
Pour concrete into the formwork. It is best to pre-order ready-made concrete, because... It will take a lot of time to independently prepare the required amount of solution.
After pouring, pierce the concrete with a metal rod in several places to remove excess air from the material. The solution will dry for about a week and will need another 3-4 weeks to gain strength.
Let the walls dry and dismantle the formwork.
Fifth stage - waterproofing
Proceed with the external waterproofing of the cellar. Bituminous mastic is best suited for this. Apply 3-4 layers of waterproofing material to the outside of the basement walls using a roller, and then stick a layer of roofing felt over the mastic. Let the insulation dry and fill the area around the walls with earth or make a clay castle.
If there is a risk of flooding of the cellar, a clay castle must be made. Mix clay, clean sand and water until you obtain a homogeneous mass resembling plasticine. Fill the hole layer by layer with the resulting mass and compact thoroughly.
Inside, both the walls of the cellar and its floor are waterproofed. It is best to fill the floor with hot bitumen and cover it with roofing felt. To insulate walls, you can use polymer mastic or penetrating waterproofing. The second option is more preferable.
When installing the floor, remember the required 1-2 degree slope of the surface in the direction of the technical pit. Thanks to the slope, the cellar will remain dry even during the rainy season and floods.
Stage six - finishing
At the finishing stage you will have to make a ladder, a manhole cover and ventilation.
If you decide to make do with a simple wooden staircase, first soak the raw materials with an antiseptic. Place the stairs at a slope that makes it comfortable for you to climb and descend.
The hatch cover must be hinged. For the rest, at this stage, be guided by your preferences.
Video - Ventilation in the cellar
Insert the ventilation pipes into the holes that you made at the stage of preparing the walls for pouring concrete. The exhaust vent should be located under the ceiling of the cellar above the pit, the supply vent should be located almost near the floor in the opposite wall. Place the air ducts outside. Place protective grilles (grids) over the ventilation openings.
The procedure for arranging the ceiling depends on whether the cellar is created during the construction of the house or whether it is installed in an already completed building. In most cases, the ceiling of the cellar is an ordinary floor slab with a pre-prepared hole for the hatch. The procedure for arranging such a ceiling depends, as already noted, on the circumstances under which the cellar is created under the house, so be guided by the conditions of your particular case.
This completes the construction of a cellar under the house with your own hands. Install the planned racks and shelves, and you can start using your own cellar.
Good luck!
Video - DIY cellar under the house