Building a basement in a house - two popular technologies

Excess humidity in the cellar occurs due to various factors. The root cause is usually an initially incorrectly designed and built storage facility for vegetables, fruits and canned goods. If the problem already exists, there are well-established, time-tested, budget ways to dry out the cellar. More convenient methods have also appeared, but they are quite energy-intensive and costly in monetary terms. But in any case, after drying the cellar, it is recommended to disinfect it.

Preventing moisture accumulation in the cellar

In order not to encounter the problem in the future of how to dry a cellar in a garage or private house from dampness, at the initial stages of construction it is necessary to take care of compliance with all the rules and regulations for ventilation and waterproofing (vapor barrier) of the room.

• It is best to fill the walls and floor with concrete based on high-quality cement (to save money, it is allowed to add low-quality substances to the solution to improve moisture repellency).
• If groundwater is close, external waterproofing will be required. It can be either in liquid form or rolled. Water protection is selected based on reliability and financial capabilities.
• If the cellar is designed on a slope, then drainage pipes will be a mandatory addition to combat the penetration of moisture into the storage.
• It is necessary to make a special blind area around the entrance to the cellar to prevent precipitation from entering it.
• In the basement, supply and exhaust ventilation are installed in different corners of the storage room (diagonally). A diameter of 12.5 cm is the optimal size for ventilation ducts or pipes. The first pipe is installed 10-15 cm short of the floor - it will be responsible for the supply of air from outside. The second, for exhaust, is mounted below the ceiling level within 10-2° cm. All ventilation is protected from direct ingress of precipitation and debris, but with a good gap. It makes sense to attach a device to the exhaust duct to stabilize draft and circulation. Ventilation pipes are installed vertically; do not tilt the pipe more than 30°. The length of a channel with a slope cannot exceed one meter.
• The storage room for fruits and vegetables in the garage or under the house is insulated with a vapor barrier to reduce the possible penetration of moisture into the lower (basement, subfloor, cellar) and upper levels of the premises (rooms of the house, garage, utility unit).

Equipment design

The cellar is constructed with monolith reinforcement using ribbed reinforcement with a diameter of 8 to 14 mm

There are two options to build a foundation with a basement with your own hands - a pile and a monolithic strip type of device. It’s worth saying right away that the first option is quite difficult to implement, so in practice we most often encounter a monolithic foundation. In our article we will discuss the construction of the basement space in the second type of house foundation. For a monolithic structure, there are the following rules for its construction:

• In the case when the construction of a basement space is planned at the design stage of the house, its depth can be about 3 meters. The bookmark is made using special equipment. The work begins with preparing the pit and depends on the type of backfill.
• When we carry out actions to create a foundation with a basement floor, there are no restrictions on the depth of the building. For optimal functioning, it is enough to correctly calculate the wall thickness for various materials.
• To avoid the negative impact of the soil in winter, you need to fill the area around the walls with sand instead of earth. This is easy to do, because DIY construction is carried out in a foundation pit, around which there are sections of territory to be filled. This action must be performed immediately after waterproofing and insulation.

• The cellar is constructed with monolith reinforcement using ribbed reinforcement with a diameter of 8 to 14 mm. If this is a small building, then the horizontal load-bearing components of the frame have this value of 10-12 mm.
• In a conventional reinforcement frame there are usually four load-bearing members, but in some cases there are also five components. The ring with the jumper should be placed at a distance of up to 80 cm, and the entire structure should be connected to each other with wire.
• An important process is waterproofing the foundation with a basement, which will help protect the room from dampness. This can be done using mastic or cellophane film.
• Thermal insulation is also necessary, especially in the case of a basement, since cold easily penetrates the monolith. To solve this problem, foam is used, but there are cheaper ways.

It is best to start building a foundation with a basement with your own hands at the same time as planning your house. This will allow you to perform calculations taking into account the basement space, which will allow you to avoid unpleasant situations in the future.

Storage floor design

The main reason for waterlogging of the cellar is closely located groundwater. Initial proper floor installation will prevent the problem of excessive moisture in the basement. There are several ways to install a waterproofing floor.

• Most often the floor remains earthen. Water from the lower layers penetrates through capillaries to the floor surface. To prevent the need to dry out the cellar from dampness, the earthen floor is leveled, compacted and covered with a thick film or roofing felt. To protect the coating from tears or breakage, wooden boards are used (possible reasons for damage to the coating: foot pressure, installation of boxes with sharp corners, careless displacement of heavy objects).
• An earthen floor can be reinforced by packing clay, that is, covering the entire floor with a compacted mixture of clay and sand. This operation, which allows you to dry the basement by creating a natural barrier for moisture to escape, is carried out in four steps:

1. One layer of crushed stone or broken brick is poured onto the previously leveled earthen floor of the cellar, and the space between the stones is filled with a thick mixture of clay with the addition of sand (clay is taken with a good percentage of fat content, and the floor level should rise by 15 cm after pouring).
2. The clay is compacted very tightly.
3. Sprinkle sand onto the compacted floor and rub it in. Remove excess with a broom and dustpan.
4. The created clay floor must be thoroughly dried for two to four weeks.

• The most profitable way to improve the waterproofing of the floor and avoid regularly drying out the cellar is to make it concrete and with a good drainage system. True, this is the most expensive method, requiring special knowledge and skills.

If after all the manipulations with the floor the level of humidity in the basement or garage decreases significantly, then you will no longer need to worry every year about how to dry the cellar from moisture (especially during the spring rise of groundwater).

How to find the groundwater level in your area

Water is the main enemy of all building structures, especially those located underground. To find out the groundwater level on the site, it is recommended to conduct small geological studies:

• Drill a hole 3 m deep. It is better to work in late autumn or spring. If the groundwater level is close, a wooden pole lowered into the well will be wet.
• Contact your local hydrogeological organization. There are all the answers regarding questions about UGV.
• Talk to your neighbors. Usually, nearby areas have similar conditions.
• Explore the area for the growth of moisture-loving plants - horse sorrel, sedge, nettle, alder, willow and others. If they are abundant on the site, groundwater is very close.

Nearby ditches, wells, and boreholes are also a source of information. Another telltale sign of a nearby aquifer is heavy dew falling at night. If, in addition to a high groundwater level, the soil has a clayey composition, building an underground cellar is very risky. It is better to focus on more “elevated” options.

Improving wall waterproofing

Poor moisture insulation of the walls of buildings is another reason for waterlogging in the basement of a garage or a separate cellar. Brick walls have many pores through which moisture penetrates and condenses out. The problem can be solved in several ways:

• Create external insulation from moisture. If possible, remove the soil from the walls and apply a two-layer bitumen mastic or resin.
• Make an internal waterproofing layer (use special impregnations with a penetration depth of up to 0.5 m to clog the pores of the cellar walls).

Good supply and exhaust ventilation and sufficient waterproofing of the floor and walls will be the key to a dry basement. But how to dry the cellar when water has already penetrated inside and begun its negative impact? The choice of method to combat dampness depends on the availability of ventilation in the cellar.

Additional preparation

Reinforcement

• with a relatively small constant load, a single-level grate with rods up to 8 millimeters thick will be required;
• for large constant loads, a volumetric frame with rods up to 12 millimeters thick will be required.

1. The lower part of the reinforced layer is not placed directly on the waterproofing. In this case, the metal will be constantly exposed to moisture and will not be protected by concrete, which will soon lead to corrosion. Before constructing reinforcement, make supports at least 5 centimeters high.
2. Lay the reinforcement in such a way that there is a distance of approximately 5 centimeters between the ends of the rods and the wall.
3. You can fasten the mesh rods using welding, aluminum wire or plastic ties. The choice depends on your personal preferences and available tools and materials.
4. Upon completion of the frame, pour concrete into the prepared pit. This is a rather lengthy and labor-intensive task, so it is better to prepare for it in advance.

Inventory

• concrete mixer - a machine for mixing concrete in automatic mode;
• hammer;
• wood hacksaw;
• building level;
• roulette;
• welding machine;
• angle grinder (grinder) - a type of grinding machine designed for abrasive processing: grinding, cutting and cleaning products made of stone, metal and other materials;
• wide steel spatula;
• plaster beacon (beacon profile) – a metal product used as a support guide to create a flat surface.

Dehumidification of a ventilated basement

In a basement of any type, a whole series of work will have to be carried out, but first it is necessary to remove from the cellar the supplies stored there, dismantled structures (shelves, racks, flooring), storage containers (boxes, crates, barrels). All wood structures must be dried in the sun and treated with a 5-10% solution of copper sulfate, regardless of whether they have been damaged by pathogenic microflora. The second step is to whitewash the walls with a double layer of lime.

• The lime is diluted so that the solution does not drain from the paint brush (you can add a 5-8% solution of copper sulfate).
• Divide the lime powder into two equal parts.
• The first part, using a paint brush, is to create gaps in the corners of the cellar and throw them with force onto the walls (you can also onto the ceiling), without trying to get a flat surface, but not forgetting about safety precautions.
• A day later, the second part of the solution is also smeared on the walls.

The end result is that on the third day, the internal surfaces of the cellar become porous and lumpy. Moisture in the form of condensation is not retained on them, since the lime takes water inside itself. As soon as the top layer of lime has dried, you should start drying the basement.

Scheme for drying a cellar with ventilation

1. Check whether the ventilation is properly arranged (if the shortcomings are not corrected, the cellar will have to be dried again, almost a couple of days after the drying procedure).

2. Check the cleanliness of ventilation ducts or pipes (remove all dirt, mold or moss growths).

3. Strengthen the air ventilation process:

• Installing a fan on the exhaust pipe. With the doors and hatches open, the cellar will dry out (depending on the amount of accumulated moisture and weather conditions) within 3 to 10 days.
• Organization of increased ventilation using a small heating device (candle, dry alcohol tablet, alcohol burner). To do this, extend the ventilation pipe above the ceiling so that a heating element on a non-flammable stand can be placed under it. Warm air will increase circulation and speed up drying of the basement.

4. Warm up the cellar if forced ventilation is unable to dry out the basement. The drying process using heating is carried out in stages:

• Take a metal bucket (preferably not new).
• We make many holes in it, both in the walls and at the bottom.
• Fill the charcoal almost to the top edge of the container.
• We light the contents of the bucket and wait for steady combustion.
• We lower a bucket of coal on a leash inside the cellar (the bucket should hang in close proximity to the bottom of the storage and a fire-resistant substrate must be placed under it).
• Close the cellar lid tightly (as tightly as possible so that the smoke escapes into the ventilation).
• We periodically open the hatch cover to allow oxygen to enter the room being dried or increase ventilation using a vacuum cleaner through the supply pipe.
• Remove the bucket of burnt coals.
• Seal the lid tightly for three to four days.
• We ventilate the dried and disinfected cellar.

Do not forget that the decision on how to dry the cellar must be safe both for those who warm it up and for the room itself. Combustion is always fire, smoke, carbon monoxide.

With this method of draining the basement, the bucket can be replaced with other heating devices. A small stove - a potbelly stove, a heat gun with good power (more than 3 kW), working kerosene gas, a gas burner (be careful - open fire) is quite suitable.

Features of pouring concrete

To build formwork for the monolithic structure of cellar walls, you can use different materials. These may include plywood, boards, OSB boards. If there is a shortage of the necessary formwork material, you can rearrange different elements as the solution is poured.

It is better to use a certain brand of cement. M200 is most suitable for cellar walls. You can also use M400 cement. Mix in the following proportions: 1 part cement, 3 parts gravel and 3 parts sand. Concrete is poured in layers. After each new layer, air bubbles are expelled from the solution. This is done using a deep vibrator.

The walls of the cellar are erected directly to the ceiling. As soon as the solution hardens, it is necessary to carry out internal and external waterproofing of the room. The inside of the cellar walls are plastered. The sand-cement layer is applied 3 cm thick.

Drying the cellar without ventilation

A cellar that is not equipped with ventilation naturally accumulates dampness. Here the question arises: how to dry a cellar without ventilation and at the same time not cause harm to health from smoke or carbon monoxide? The answer is obvious - this cannot be done. You will have to install at least simple ventilation.

Before installing ventilation ducts, you can collect moisture in the basement in several simple ways. To do this, you will need materials with a high level of hygroscopicity:

1. Sawdust - regularly change wet to dry.
2. Calcium chloride - place around the perimeter and in the center of the cellar (you can calcinate it, not forgetting that it is caustic, and use it many times).
3. Place slaked lime along the walls and on shelves.
4. Ordinary thick cardboard from furniture packaging or boxes - lay out dry ones and change when wet.

In addition, there are high-tech ways to dry the cellar from dampness. For example, dehumidifiers, which are most often used for rooms where there is open water (swimming pool, jacuzzi, decorative pond). True, the cost of a dehumidifier ranges from 20 thousand rubles and more. But they will properly perform their function when draining a damp basement; you just need to drain the water they collect in a timely manner.

Questions and answers

Finally, we will try to answer some typical questions from novice builders.

Is it possible to leave the bottom of the cellar unpaved?

If the groundwater level is consistently low and there are no floods, yes. However, in this case, you will periodically encounter an invasion of bugs and worms. A dirt floor will not protect you from rodents either.

How much does it cost to build a cellar?

The question is incorrect: cellars are different. The minimum cost for self-construction will be approximately 30,000 rubles (cement, brick based on half-brick masonry and a cellar size of 2x2x2 meters, reinforcement and sand). The maximum construction budget can amount to millions of rubles.

How to make a staircase to the basement?

The optimal slope is no more than 60 degrees to the horizon. The minimum width of the steps is 35 centimeters, depth - 15. The presence of handrails is highly desirable for safety reasons.

The staircase in the photo is very compact; however, climbing it with a load in your hands is a non-trivial task.

Ways to combat pathogenic microorganisms

Excess moisture that is not dried in the cellar in time leads to the massive development of harmful microorganisms. All kinds of mold and fungi multiply rapidly and cause harm both to all wooden structures and to products stored openly. Spores of harmful microflora have a very detrimental effect on a person in an infected basement. The following agents are available to combat pathogenic microorganisms:

• Quicklime (install a barrel of lime in a ratio of 3 kilograms of dry lime per 1 cubic meter of volume, fill with water, leave the room, seal the basement, ventilate after two days).
• Sulfur checker (you must first remove metal objects from the cellar or cover them with a layer of lubricant. Place the checker on a fireproof stand, light the wick, trying not to inhale the smoke, quickly leave the room being processed, tightly close the hatch and ventilation, ventilate for 24 hours every other day).

Preparatory stage

The appearance of moisture in a cellar or basement does not go away without leaving a trace. This usually leads to the formation of mold and its spread throughout the basement. Therefore, before starting to dry the basement, it is necessary to go through the preparatory stage. The basement or cellar room is carefully inspected and the general condition is assessed. After this, it is necessary to lift all the elements that are in the cellar. This applies not only to food supplies, but also to the various shelves that are also present there. If the frame is made of metal, then it will need high-quality maintenance. It is better to do this during the transition period - in the middle of summer. The air outside is warm, but the cellar is empty, because it is too early for new preparations. Wooden flooring from the shelves must be exposed to the sun so that the ultraviolet rays fulfill their role.

All mold in the cellar or basement will need to be removed with a brush. After this, the surface is treated with an antiseptic composition and, if desired, painted. Simultaneously with emptying the cellar, it is necessary to open its entrance and leave it in this position for several days. This is done for preliminary ventilation. The procedure should only be carried out if the weather is nice and warm outside. If the basement is equipped with forced ventilation, then the air will remove some of the moisture. It is advisable to inspect the ventilation ducts to make sure that they are not clogged.

How to deal with humidity after a flooded cellar

Flooding of the cellar can occur due to rising groundwater, penetration of precipitation, or accidental flooding. The reason is not important when it is necessary to decide how to drain the cellar from groundwater or how to dry the basement in the garage from excess moisture. The scheme is simple:

1. Use a pump or drainage pump to pump out water from the storage floor.
2. Clear out the basement.
3. Dry for a couple of days with the hatch open and ventilation.
4. Collect trash.
5. Whiten with lime.
6. Dry the cellar using one of the above methods.

There are settlements where flooding of the basements of private houses and cellars occurs regularly. In this case, it is necessary to strengthen the floor drainage.

Digging a pit

The method of digging has not changed in the last few hundred years; the set of tools is also quite traditional - a shovel, a pick and a bucket for excavating soil. It is clear that for the work it will be necessary to completely open the floor in the room under which the cellar is located.

What you should pay attention to?

• If the location of the pit relative to the foundation of the house allows such liberties, it is desirable that the pit be larger than the expected dimensions of the cellar by half a meter in each direction. The gap will be required in order to perform external waterproofing of the walls.

A caveat: this is relevant for the construction of brick walls. When they are poured with concrete, the walls of the pit serve as the outer part of the formwork; Accordingly, no clearance is required.

• The typical pit depth is 2.5 meters from the floor level in the house. Taking into account the thickness of the bedding and screed, the height of the room will be slightly more than two meters, which is quite enough for a tall person to move comfortably.

Approximate dimensions of a small cellar.

• If the groundwater level is consistently low, it would be a good idea to dig a drainage well into which condensation or water seeping through the walls during a rainstorm can drain. Its depth is no more than a meter, diameter is about 50 centimeters.

When the water level is high, a well (more precisely, a pit) is also built, but with sealed walls. It serves to collect and subsequently pump out water using a drainage pump.

Pit with drainage pump.

Structure of the external entrance block

Installation of the entrance to the ground floor should be started only after it has been decided which rooms will be located there. Agree, it matters whether this room has a garage or a playroom where noisy gatherings will take place. Moreover, if this is the main entrance to the house, then the work on its arrangement will be appropriate.

Entrance hatch: photo

This type of entrance to the basement is used if the purpose of the room is a warehouse or utility room. It is a kind of hatch that is closed using flaps or an inclined lid.

Which entrance is most convenient?

Once the purpose of the basement is clear, it is necessary to determine how the entrance opening should be arranged. The choice consists of two solutions - compact or marching.

1. Compact entrance, which is closed with an inclined lid or doors. Ideal for a small yard with infrequent use. The steep descent is inconvenient. The positive aspects: excellent thermal insulation, impossibility of moisture from entering from outside. A compact opening is installed when the ground floor is the basement of a house or a warehouse.
2. The main entrance is a classic staircase, made of various materials and differing in style. The frame of the staircase is chosen based on the external situation at the door. This type of staircase is much more expensive than the previous one.

In this video you will learn more about the entrance to the ground floor: