How to build an observation pit in an open area. How to make an inspection hole in the garage with your own hands: step by step instructions, sizing, drawings and photos

21.06.2018

In our country, the inspection pit is planned for the first time during the construction of the garage. It is an excellent assistant to any motorist, since it allows you to carry out minor repair or preventive work, as well as diagnostics, and without much material costs. From this article, you will learn how to make a viewing hole in the garage, what materials will be required for this, and also what its general benefits are.

What is a viewing pit for?

The answer is obvious: it is needed in order to make it more convenient to service the vehicle. In case of breakdowns, some turn to special technical centers, but most of the motorists prefer to carry out the most complex operations with their own hands. And it is much more convenient to do it in a cozy and calm atmosphere.

In addition to practical work, the inspection pit is able to provide easy access to:

chassis of the car;
exhaust pipe;
bottom;
sump;
gear box;
muffler.

Now, having familiarized ourselves with the purpose of the inspection pit, we proceed directly to work.

How to make a viewing hole yourself

The process consists of several stages, let's consider them.

Stage one. Preliminary markup

First, you must determine the shape and dimensions of the inspection pit in the garage. This extremely important point, since the pit will be settled in an existing garage, which, accordingly, will complicate the task, and the working conditions will be cramped.

When marking, be guided by the fact that the soil that forms the walls of the pit will have some slope, while the dimensions of the structure themselves should be such that work in it is as convenient as possible. This is the first thing. And secondly, in the future, you should easily park over the pit, without fear that the vehicle will fall into it. There are certain measures to prevent slipping, but more on them later.

Based on all this, the working width of the pit should be 70 cm - in this case, even the smallest car models will have about 15-20 cm for maneuvers. The width can be increased if necessary.

Note! If you are a happy owner of a Zhiguli with a 1.3 m track width, you can increase the width of the pit to 80-85 cm.

The length of the structure is also determined for convenience reasons, but the area of \u200b\u200bthe garage itself should also be taken into account. In any case, it should be at least 2 m.

Using pegs with a rope or a small amount of lime, mark the perimeter of the pit on the floor, add wall thickness on each side (depending on the stability of the soil) and make a small margin for the slope. If we are talking, for example, about dense loam, it should be about 25-30 cm. But the depth should be such that about 25 cm remains from the top of your head to the bottom of the car. Let's give a small example.

Example .

For this we use all the same Zhiguli. The clearance of this car is about 16 cm. And if your height is, say, 1.8 m, then the "clean" depth of the pit should fluctuate within 1.7-1.8 m. Although it is better to make it a little larger, because in the future you can always equip the raised floor to the required height or, alternatively, substitute a bench.

Stage two. Preparation of equipment and consumables

During the work you will need:

rule;
concrete mixer;
capacity;
shovel;
self-tapping screws;
concrete;
boards;
bulk building materials;
screwdriver;
roulette.

The amount of this or that material depends on the size of the future structure.

Stage three. Excavation

You have to dig about 9 m³ of earth, which is difficult, especially if the soil is solid and the work will be done by hand. This is the most difficult of the stages, but professional excavators can be involved in the work.

After digging a trench, leave some of the earth in the garage or next to it - with its help, you will fill the sinuses at the end of the construction of the walls. Take out the rest. To correctly calculate the equipment required for removal, remember: the volume of the loosened soil will be approximately ¼ more than the volume of the pit itself.

After that, level the bottom of the trench and compact it using fine gravel. To do this, sprinkle crushed stone in a layer 5-7 cm thick and compact it with a tamper.

Note! It will be much more convenient to work in the inspection pit if you make niches in the walls for materials, tools and spare parts. Provide such niches in advance, even at the stage of excavation.

Stage four. Wall and floor construction

There are two possible materials that can be used in this case:

brick;
concrete.

We recommend using the second option as it will be cheaper. In addition, the design will turn out to be more reliable, and the embedded elements will be fixed better. Therefore, we are considering an option with monolithic concrete.

Step 1. First, build a 6-7 cm thick concrete floor on top of the crushed stone.Reinforce it with a reinforcing mesh 3-4 cm thick and a maximum mesh size of 15x15 cm.

Step 2. Prepare concrete in the following proportion (for 1 m³): "four hundredth" cement (300 kg) + crushed stone with a particle size of 0.5 to 2 cm (1210 kg) + water (210 l) + sand (680 kg). If you mix by hand, then you will need a little more water, although it is still recommended to use a concrete mixer - this will make the finished solution more mobile.

Step 3. Fill the floor with the resulting solution.

Note! The compressive strength factor of such a surface will be approximately 200, which is quite sufficient in this case.

Step 4. Prepare wall mortar. The proportions here should be somewhat different: 360 kg of the same cement + 1168 rubble + 670 kg of sand. The volume of water is the same - 210 liters. The walls will be 15 cm thick.

Step 5.Construct the formwork from OSB boards 1-1.2 cm thick. In the future, these plates may be required for other needs.

Step 6. Reinforce walls. Many neglect this, but it is better not to skimp on quality. You can use the same mesh for this as for the floor.

Step 7... Pour the concrete in layers, the height of each tier should be 30-40 cm. Compact each tier with a bayonet shovel. In the last tier, equip the "glasses" of a cylindrical shape, into which then install the lamps. To do this, place pieces of the sewer pipe (always at an angle) into the holes in the formwork.

Step 8. From pre-welded metal corners, frame the pit; for fastening, use embedded anchors made from pieces of reinforcement. Framing will perform several functions at once:

strengthening the corners;
"Clip" for plank flooring;
a curb for belay (so that the car does not slip).

Step 9. Backfilling. In the resulting gaps, cover the earth in layers of 15-20 cm, carefully tamping each of them.

Stage five. Waterproofing

If in your area the groundwater level is high enough, then additionally take care of high-quality insulation. There are several options here.

Roofing material... It is laid in two layers on top of the bituminous mastic. The overlaps should be 20 cm, all of them are also glued with hot bitumen. The shelf life of such insulation is up to 15 years.
Dry penetrating mixtures... They are diluted with water immediately before use. The mixtures penetrate deep into the structure, but are mainly used as additional insulation.
Polymer membranes... They are distinguished by a long service life (up to 50 years). Installation involves the arrangement of a reinforced frame and laying a layer of geotextile. The membranes are self-adhesive, the overlap should be 10-30 cm.
Oily clay + waste from the oil refining industry... Practically not used.

What else to look for?

If the lighting will be provided by the above-mentioned cylindrical recesses, then cable routing and installation of the socket will be required. If the light source is portable, then all this is not needed.
Ventilation may be required to protect the pit from condensation, fresh air and the outflow of various chemicals. The easiest way to do this is with a flexible air duct, which should be led out of the pit 25 cm above the floor level.
When carrying out earthworks, fasten the walls of the pit without fail! Use planks with spacers for this.
Finally, when doing the work, use the means individual protection (boots, gloves, if necessary - respirator and goggles).

Do-it-yourself inspection pit in the garage: video

Outcome

The inspection pit is easy to make yourself. Of course, it is easier to do it even at the stage of building a garage, but it will not be difficult to do it in a finished structure. With such a "bunker" it will be much easier for you to repair and maintain your car.

As a result, we note that it is better to work with an assistant. He will not only help or give tools, but also come to the rescue in an emergency.

Experienced car enthusiasts who independently repair their cars know how necessary it is to have an inspection pit in their own garage. This simple recess in the floor allows you to inspect and, if necessary, repair the lower part of the car, exhaust pipe, muffler, gearbox, engine and other hard-to-reach places. If there is a pit, you do not need to pay for a simple oil change procedure in a car service.
However, the existence of such a structure in the garage inevitably leads to high humidity. Therefore, if the size of the room allows, it is recommended to make it away from the place where the car usually stands. Otherwise, water vapor accumulating above the pit will condense on the bottom of the car and lead to its rapid corrosion.
Ideally, when you think about building a viewing pit before building a garage. But you can equip it in an existing garage, although you will have to face a number of restrictions. Doing this work with your own hands is not so difficult, the main thing is to know how! When performing work, it is advisable to study building codes and strictly observe construction technologies... Then the results of labor will delight the owner for many years and the sad consequences will be avoided.

Step one: sizing

Work on the arrangement of an inspection pit for a garage begins with its design and calculation of dimensions. It makes sense to record the results of these works on paper in the form of a garage plan and a drawing of a pit. It is necessary to think carefully about where it will be located, how the car will enter the garage. The required dimensions of the inspection pit depend on the width and length of the vehicle, the size of the garage, and the height of the owner. It is important to make the right calculations, otherwise the mistakes made will cost too much later.

The required allowances should be added to the dimensions obtained on each side for subsequent finishing work, waterproofing and insulation. The dimensions of the allowances for brick walls are 12 cm, for concrete - 20 cm on each side. The allowance for the floor is 20 cm. If waterproofing or insulation of the pit is expected, the allowances must be increased.

If the groundwater level is higher than 2.5 m, then the pit will be flooded

It is imperative to find out how deep the groundwater is in the soil. This information is included in the pre-garage survey report. The groundwater level in the area where the garage is located plays a very important role. If it is higher than 2.5 m, then an inspection hole cannot be made in an already built garage, since it will be flooded. In a garage under construction, you will have to make a drainage system that removes excess water into the sewer. If the groundwater is deeper, there are no contraindications for construction.

In niches, you can place the tool necessary for repair

It is convenient when small niches are made in the walls of the inspection pit. The tools needed to repair the car are usually located there. Places for niches, their sizes should be thought out in advance and drawn on the plan. The depth of the niches is usually 15–20 cm, the length and width are determined at the discretion of the owner.

Step two: planning and executing construction stages

After work "on paper" comes the turn of work "on the ground". The stages of construction of the inspection pit are as follows:

Markup. On the place of the garage allocated for the pit, markings are applied with chalk or a marker, taking into account the calculated allowances, after which the existing floor is dismantled. It is not recommended to make a viewing hole close to the garage wall. The distance to the wall must be at least 1 m;
Preparation of the pit.This is undoubtedly the most difficult stage, but workers can be hired to complete it. You will have to remove about 8-9 cubic meters of soil. The duration of the process depends both on the capabilities of the worker and on the properties of the soil. You need to dig with a bayonet shovel, sometimes with a pickaxe, starting from the far end of the future pit. Plank spacers may be required to keep soil from falling off the walls.
Loose soil takes up 20-25% more space, so this must be taken into account when removing it.

Part of the land must be left to fill the sinuses. Inside the excavated pit, the resulting walls and the floor must be leveled by hand tamping as carefully as possible. After the surfaces are ready, the bottom is covered with a layer of gravel 10 cm thick, well tamped. Pour 5 cm of sand on top, then tamp it again. If the soil is wet, then 5 cm of clay is poured for waterproofing, covered with the same layer of gravel. The surface is covered with plastic wrap, after which it is reinforced with a metal mesh;
Do-it-yourself walls and floor of the inspection pit. The bottom of the pit prepared in this way is poured with a layer of concrete mortar 7–8 cm thick, and left to dry for several days. After the concrete has hardened, you can proceed to reinforcing the walls with a mesh. To fill the walls with concrete, formwork is needed, which is usually made from OSB sheets. Then from them you can make shelves for tools. The formwork is installed in tiers of 30–40 cm, connecting the elements with spacers. At the same time, a metal mesh is laid in two layers. In addition, embedded parts are used that are firmly fixed in concrete. Particular attention should be paid to the reinforcement of places for niches.
The space between the formwork and the edges of the pit is poured with mortar. The last layer of concrete is laid with a metal corner protruding 10 cm above the surface. Such an edging is needed so that, entering the garage, you can see where the pit is. Subsequently, boards are laid on it, covering the inspection pit.

The formwork is removed 2 weeks after pouring the walls, after which the concrete is allowed to harden for another month. This is the only way to guarantee the strength of the walls. When the concrete hardens, they proceed to backfilling the soil, and then to interior decoration inspection pit. Backfilling of the sinuses is carried out with clay or loam, which well protect the pit from water penetration. Pour 15-20 cm layer by layer, tamp well. Instead of clay, you can use the original soil, but it must be tamped especially carefully. Ceramic tiles have recently been used for finishing walls and floors. Another option is to plaster the walls with white gypsum plaster.

Step three: waterproofing and insulation

The pit preparation procedure described above is applicable when the garage is located in an area with sufficiently dry soil. If the soil is wet, there is a risk of flooding and constant dampness inside the pit. In such a situation, additional measures are needed to waterproof the bottom of the structure.

To do this, before pouring concrete, layers of special materials are laid on the floor to prevent moisture penetration. The edges of a piece of material should overlap the walls by 15–20 cm.

The most commonly used:

Materials based on bitumen (durable, inexpensive, easy to install);
Polymer membranes (strong, durable, well compatible with other materials);
Penetrating waterproofing (high degree of protection against moisture, resistant to temperature fluctuations);
Liquid rubber (very high degree of protection, but the surface to be treated must not be damaged).

For additional protection against moisture, the concrete solution is prepared using special additives.

In order not to freeze when repairing a car in winter, it is better to insulate the inspection hole. In this way, you can additionally save on electricity consumed for heating the garage. Insulation should be provided even at the stage of determining the dimensions of the pit. Among modern heaters, expanded polystyrene is considered the best. It has the following properties:

Does not rot;
Does not burn;
Does not allow moisture to pass through;
Attaches well to concrete surfaces with glue;
It's cheap;
Safe for health.

Step four: additional arrangement

In order to work comfortably inside the inspection pit, a number of additional work must be performed:

Adequate lighting is required to inspect the vehicle

Important details when arranging an inspection pit

When carrying out work on arranging a viewing pit for a garage, one must not forget about personal safety measures:

When excavating in soft, unstable soils, starting from a depth of 1 m, install spacers and plank reinforcements. The fact that the soil is crumbling usually becomes visible immediately;
Use protective equipment: gloves, mittens, sturdy boots, goggles, especially when working with a grinder or hammer drill;
Work together with an assistant. It's much easier, faster, and safer.

These rules will help you cope with work without harming your health.

Video

Watch a video about the construction of an inspection pit in the garage with your own hands.

If you want to equip your garage in such a way that it has maximum functionality, then its space must be supplemented with a viewing hole. Moreover, you can not only store your car in it, but also store things, repair and inspect the car.

Features of the inspection pit

If an inspection pit in the garage will be equipped with your own hands, the dimensions must be chosen at the first stage. But it is important to think about whether you really need such a component. Two decades ago, the presence of this element in the garage was not discussed, however, with the development of the service station, a category of car owners appeared who did not see the point in servicing the car on their own. An inspection pit in the garage with your own hands made of iron can be equipped. But if you do not want to waste time and effort on an independent technical inspection, then you will not need it. Some argue that a depression in the garage can negatively affect the elements of the car, because fumes rise from the bottom. This is true only if the work is not done according to technology. After all, it is important to insulate the pit, to make it convenient for your own use. By equipping the underfloor space with a sealed lid, you can be sure that even a poorly insulated pit will not be a source of fumes.

When there is no way to equip a viewing pit

An inspection pit in the garage with your own hands may not be equipped in all cases. This will depend on the groundwater lines. If their level is above 2 meters, then carrying out such work will be impractical, this is due to the fact that the space will be filled with water. But if necessary, even the most critical conditions can be overcome by having a good drainage system, as well as high-quality waterproofing. An inspection pit in the garage with your own hands from concrete is often built quite often, it also needs to be supplemented with drainage, but this task is quite difficult, it should be dealt with exclusively knowledgeable people at the stage of building a garage. If this system is to be created on an existing building, this may be accompanied by the application of a large amount of manpower and resources. Among other things, such manipulations are not always effective.

If the occurrence of groundwater under an existing building indicates that the pit should be abandoned, then this clue must be heeded. An alternative solution may be the equipment of a recumbent pit, which may well replace a full-fledged one in some cases. If an inspection pit in the garage will be equipped with their own hands, then it is necessary to invite the appropriate specialists who will be able to analyze the level of occurrence of groundwater. If you decide to spend the least amount of money on carrying out these manipulations, then you can check it yourself, but it will take much more time. To do this, a pit should be dug, but it should not be immediately concreted. You need to wait for the flood season, heavy rain will do. After that, you will be able to assess its consequences.

Inspection pit dimensions

If you think the viewing hole is a fairly standard part of a garage, you might be wrong. Such a device can have several options. It can be combined with a cellar and basement, make a narrow recess, which will be operated with ladder, as well as arrange a lying pit, which was mentioned above. The dimensions should be chosen depending on the master who will most often use the pit. It is also important to consider the size of the vehicle, as well as its intended location. The width should not be less than 80 centimeters, 1 meter can be chosen as the optimal parameter. In depth, the pit should measure between 1.8 and 2 meters. This parameter is the most important, and it will depend on the height of the person. Most suitable option it is considered a depth that is 15 cm greater than the growth of the master. Most often, a size within 2 meters is used as a length. If an inspection pit in the garage will be equipped with your own hands, then when planning it is necessary to take into account that the mentioned indicators are not given for the pit itself. It is necessary to dig it out with allowances of 50 cm in width and length. As for the depth, you need to increase it by 25 cm. If you plan to insulate the walls, then the dimensions of the pit must be increased by the width of the insulation, most often this figure is 50 millimeters.

Floor arrangement

After the pit has been prepared taking into account the selected dimensions, you can tackle the floor. If you approach the construction correctly, then there will be no issues with dampness during operation. Thus, it must be borne in mind that the inspection pit in the garage, equipped with your own hands, must be equipped with ventilation. To do this, a hole is left in the floor through which a flexible hose is introduced under the ground and on the surface. It is a duct on which a cover is put on. Initially, it is necessary to fill the preparation for concrete. It will be represented by two layers, the first of which assumes the presence of gravel, while the second - sand. The first layer is covered with a thickness of 10 centimeters, the second - 5 centimeters. Each of them must be watered and well compacted. The surface of the floor should be treated with clay and a layer of waterproofing should be laid. Further reinforcement is mounted and concreting is performed. As soon as the layer of mortar gains its strength, another layer of waterproofing should be put, only after the master can begin finishing.

Alternative floor arrangement

If you do not want to bother yourself too much, then you can go the easier way, for this, it is enough to lay out the bottom of the inspection hole with a brick. However, this approach can be considered rational only if the groundwater is located at a sufficient depth. This is due to the fact that good waterproofing cannot be achieved.

Selection of materials for waterproofing

If you are going to equip a home-made inspection pit in the garage with your own hands, you can choose its size yourself. However, it is important to consider waterproofing as well. There are a great variety of such materials on the market, but it should be borne in mind that the one you choose must be effective. This is especially important for the reason that the pit will be exposed to heavy loads in terms of excess moisture. However, it is important to exclude the option of overpayment. Guided by the above considerations, from a number of commercially available materials, one can especially distinguish polymer membranes, which are presented in a single-layer version. Their thickness can vary from 1.5 to 2 millimeters. As for two-layer membranes of this type, their maximum thickness can be equal to 3.1 millimeters. This material is characterized by resistance and durability. But he has the most impressive price in comparison with others. Rather, installation will be expensive, which requires the need for special tools and certain skills.

If you want to save money, then you should choose bituminous materials, these include roofing material and bituminous grease. It is quite easy to install them, but you should not rely on a service life that exceeds 20 years. A do-it-yourself inspection pit being constructed in the garage, the dimensions of which were mentioned above, can be waterproofed with bituminous components. The material is sold in rolls, you can cut it according to the required dimensions, and then stick it with an overlap of 15 cm. You can gluing by heating or using a bituminous solvent. An alternative solution to the above two methods is a waterproofing lubricant. It was invented relatively recently and is inexpensive. It is easy to apply. The surface must be moist, then the material will completely saturate the concrete and protect it from excess moisture.

Insulation of the inspection pit

An inspection pit in the garage with your own hands (a photo of which is presented in the article) is rarely insulated. Experts say that inexperienced craftsmen needlessly neglect this manipulation.

This is especially true for those garages that are heated. If you make thermal insulation, then you minimize heating costs.

Insulation must be glued to brick or concrete, after the wall and floor can be exposed decorative finishing... If, when carrying out waterproofing work, you may doubt the choice of a certain material, then experts advise using expanded polystyrene as a heater. However, it is important to consider the labeling. Thus, PSB-S-35 is perfect for the floor, while PSB-S-25 can be used for walls.

Building walls

If a home-made inspection pit is being set up in the garage, then one of the two most common solutions can be chosen for its walls. One of them involves the use of concrete, while the other is the use of bricks. If desired, then both options can be plastered or tiled, as well as fiberglass. Preparation before using concrete or brick looks the same. The surface of the walls is covered with a layer of clay, on which dense polyethylene is covered. At the next stage, the formwork is installed, while the thickness should be equal to fifteen centimeters.

When a self-made inspection pit is performed in the garage with your own hands, the construction of walls must be accompanied by the fulfillment of two conditions. One of them provides for the need for a safety rail. Its task is to prevent the wheel of the machine from falling into the pit. Among other things, it prevents water from the wheels from entering directly into the pit. It should be made in the form of a strip, which resembles the shape of the letter T. It is based on metal, and the element must be strengthened to the formwork, placing it flush with the floor surface. This strip will act as a support for the cover. Among the additional components are niches and ledges in the wall, they will become shelves for various tools and necessary things. The master will be able to appreciate the convenience of such protrusions at the first use of the pit for its intended purpose.

Lighting

If an inspection pit is built in the garage with your own hands, she just needs lighting. Some masters oppose the presence of lighting fixtures inside. A number of car enthusiasts use portable lamps that have a powerful battery. However, if you take into account the level of comfort, then the presence of indoor lighting is worth considering. If you want to equip everything according to the rules, then you should be guided by SNiP, which indicate that the voltage in the outlet inside the pit should not exceed 36 V. For this voltage, you can find special lamps. It is strictly forbidden to use standard 220 volts inside, as they can become a threat to life.

Pit cover

When an inspection pit is being set up in the garage with your own hands, you can create a reliable cover from the boards. To do this, use wood with a thickness of 50 mm. However, a thickness of 35 millimeters will suffice. This is due to the fact that the boards will not experience a constant load. The lid can be made of different materials, it will depend on what the edging of the pit was formed from. If it is a steel corner, then the cover can be made of several shields. Small rollers can be fixed in their lower part. Shields can be formed from wooden planks, the width of which varies from 30 to 35 millimeters. When an inspection pit is made in the garage with your own hands made of bricks, the cover can be formed according to the roller shutter principle. To do this, use boards with a thickness of 40 millimeters, while the length will correspond to the width of the pit. On each board, grooves must be made from both ends into which a steel cable is threaded. Springs should be installed between it and the bar, which will provide mobility. The cable is fixed to the last board, while the handle is installed at the opposite end. It will only be necessary to pull a little on it, which will open the hole as much as necessary for carrying out a certain type of work. In general, almost all materials can be used to make any part of the pit and its components.

In contact with

Classmates

TO which motorist knows how sometimes inspection pit in the garage! It happens, a nonsense breakdown, to eliminate it in one piece, but try, get it! Or changing the oil - five minutes to do, but you have to trudge to the service station and pay an amount that is completely incommensurate with the work!

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It's worth it, perhaps, to shed a little sweat, work a few days off and get rid of such difficulties forever! How to make a viewing pit dy and find out here.

Getting started. Inspection pit marking

As for everyone, even the simplest structures, we begin the construction of our pit with marking, that is, with determining the outlines and dimensions of the future pit. This is necessary, especially since we will be building a pit in an already built, or even existing one. That, you see, complicates our task, if only because of the cramped working conditions.

We will mark the pit based on the fact that the soil forming the walls of the pit will have a certain slope, while the dimensions of the inspection pit should be kept within the limits that make the work convenient.

This is on the one hand. On the other hand, while parking, the driver should not be soaked in cold sweat for fear that the car will fail. For insurance against slipping, we will take certain steps, but more on that later.

Based on all the above requirements, we will determine the width of the pit "clean" (that is, by the width of the working space) at 70 cm. This is enough for comfortable work, and even for the Daewoo Matiz crumb (128 cm track) there will be room for maneuver of the order 20 centimeters (between the pit and the wheel). And for "Zhiguli", with their 132 cm track, the width can be made even more. About five to ten centimeters, but that's not bad either.

The length is determined based on personal concepts of the convenience of work, as well as the size of the garage, but making it less than two meters is hardly justified.

On the garage floor, draw (or mark with pegs) a rectangle of our pit, then add wall thickness on all four sides and, guided by the qualities of soil stability, give an approximate margin for the slope of the earthen walls. For dense loams, this value is approximately 20-30 cm.

The depth is determined from the requirements of ergonomics, and in relation to your beloved. It is clear that bending over, or standing on tiptoe, you won't get much work. Therefore, we calculate our pit in such a way that there is a distance of 25-30 cm from the top of the head to the bottom of the car.

With a ground clearance of about 16 cm ("Zhiguli") and a worker's height of 180 cm, the depth (again, "clean") will be about 1.70 -1.80 m. It is better to dig a little here than not to dig, if necessary, under your feet you can always substitute a bench, or make a raised floor at the desired height. All this is clearly shown in Fig. 1.

Do-it-yourself earthworks for the inspection pit

Now we have to imagine ourselves as a mole for a while. After all, you will need to take out about 9 cubic meters of earth, a lot, especially if you dig by hand, and the soil is solid. But let us console ourselves with the fact that this is the most time-consuming part of the work (in extreme cases, diggers can be hired).

Part of the soil must be left, stored next to the garage, or inside it. This land will be useful for filling the sinuses, after the walls of our structure are completed. We export the rest of the land. When calculating the equipment required for removal, it must be borne in mind that the volume of loosened earth will be approximately 20-25% greater than the volume of the pit.

We level the earthen floor of the excavation, and then we perform compaction with rubble. To do this, pour crushed stone in an even layer, with a thickness equal to one and a half sizes of the largest pieces. After that, we “drive” the crushed stone into the ground with a rammer.

The inspection pit in the garage will be much more convenient for work if niches are placed in the walls where you can put tools, spare parts and various materials. Places for niches must be foreseen in advance, at the stage of earthworks.

How to make the walls and floors of the inspection pit with your own hands

For the construction of walls, the most common and proven possibilities are two: block masonry (brick) and monolithic concrete... Both solutions have their advantages and disadvantages. We recommend and will continue to consider monolithic concrete. At the cost of materials (especially if you prepare concrete yourself) it will be cheaper. When installing embedded parts, you can perform their high-quality, durable fastening. And the structure as a whole will be more reliable.

We start by making a concrete floor over the soil compacted with gravel. Six to seven centimeters of thickness will be more than enough for him. We reinforce the floor with a wire mesh with a mesh of no more than 150x150 mm and a reinforcement thickness of 4-5 mm.

We prepare concrete based on the following proportions per 1 cubic meter of concrete: 300 kg (0.28 m 3) of PC cement, grade 400; 680 kg (0.47 m 3) of sand, 1210 kg (0.9 m 3) of crushed stone with a fraction of 5-20 mm and 210 liters of water. When mixing by hand, you will have to add more water to make the mixture more mobile, but when using a concrete mixer, it is better to keep the proportions close to those indicated. If you add water much more than the norm, we will also increase the amount of cement by ten to fifteen kilograms.

The concrete obtained in this way will have a compressive strength grade of 200, which is more than enough for us.

We will make the walls 15 centimeters thick, this is quite enough for our pit. The composition of concrete is slightly different than for the floor: cement 360 kg (0.33 m 3), sand 670 kg (0.46 m 3), crushed stone 1168 kg (0.86 m 3), water is the same 210 liters.

We will concrete the walls in layers, in tiers of thirty to forty centimeters high, compacting with bayonet, for which a narrow shovel is well suited. It is impossible to compact a thicker array manually, unless you can get a deep vibrator somewhere (say, rent it). But in this case, you should not make the tier more than 50 cm.

As a formwork, we use OSB sheets with a thickness of 10-12 mm. Subsequently, OSB will come in handy for various garage needs: to make shelves or racks, door sheathing for insulation, etc.

When constructing the walls of the inspection pit, reinforcement is sometimes neglected, but it is better not to be stingy and still perform this operation. As reinforcement, you can use the same mesh as for the floor. Install it at a distance of 3 cm or a little less from the inner plane of the wall. Installed at once to the entire height of the pit, the mesh will interfere very well, therefore, we will mount it in strips while concreting.

, we immediately carry out the installation of wall niches. We reinforce the “ceiling” of niches along the entire length with two or three reinforcing bars (A-III reinforcement with a diameter of 8-10 mm will be enough) so that they do not move, we fasten them together with wire.

In the last tier, it will be useful to provide inclined cylindrical "glasses", where we will later install the lamps. The device of such glasses can be provided by obliquely inserting into the formwork, cut at an angle plastic sewer pipe (see fig. 2).

We frame the perimeter of the pit with an embedded part welded from corners with a shelf width of 60-70 mm. The "mustache" (anchor) of the embedded part is made of reinforcement identical to the one that we used to reinforce the niches. The length of the anchor is assumed to be 50 cm. If, when installing the part, the anchor does not fit along the height of the tier, you can bend it as needed.

The framing performs several tasks: it strengthens the corner of the wall, serves as a "clip" for laying the plank flooring, and finally, as already mentioned, it plays the role of a safety curb preventing the car wheels from sliding into the pit (see Fig. 2).

So that our concrete does not collapse when moving the formwork, you need to let it grab, for two to three days. After the installation of the last tier, before the start of backfilling, let it stand for at least a week.

Backfilling is done with loam, in layers of 15-20 cm, carefully ramming each layer. Ideally, backfilling can be done with so-called "incompressible" soil (crushed stone, gravel). However, it is expensive, and it is not particularly necessary for a passenger car.

You can go for a trick. After we do it, do not immediately concrete the floor, but pour it in crushed stone to the desired height (if the floor has already been completed in the garage). After a couple of weeks, driving in and out of the garage, you tamp the soil with your wheels in the places of the sinuses, after which you can safely concrete the floor, it is guaranteed not to sag.

Additional work on the construction of the inspection pit in the garage

It is not enough to make a viewing hole, it is also necessary to "equip" it. To do this, we install the lamps, and we do the overlap of the pit (flooring).

For flooring we use wide boards "forty" (40 mm thick). Boards can be knocked down into several shields, but you should not make them too large and heavy.

If a voltage of 220V is used, the wires must be hidden in a corrugated hose (preferably steel). We use the sockets and the switch on a floor sealed, waterproof.

Do-it-yourself waterproofing of the inspection pit

If the level of groundwater is high in your area, and there is a danger that the inspection hole will be flooded, high-quality waterproofing is necessary.

We will perform complex waterproofing and, as the first "line of defense", we will use a barrier made of rolled materials.

We lay a layer of waterproofing film (aquaizol, butyl rubber, etc.) under the concrete of the floor, so that the edges of the panel overlap the walls at least 15-20 cm along the entire perimeter. While concreting the walls, we consistently lay the layers of insulation. We carry out the laying with an overlap, not less than 15 cm.

If there is a danger of flooding, we make it with oily clay, ramming it in layers of 15-20 cm.

The final protection measure will be the addition of water-repellent additives to the concrete during its preparation.

In custody

A few words about "labor protection", more precisely, the protection of your health, from this very work.

Excavating in unstable soils, be sure to fix the walls of the pit, (to ensure their slope along the line of the natural slope is obviously a more laborious task). The fact that soils are unstable and prone to collapse will be evident already at the beginning of excavation.

We carry out the fastening by placing boards on the walls and securing them with spacers. It is advisable to do this when the depth of the pit reaches a meter or a little more.

However, if the soil is unstable, then there is a possibility that without strengthening the walls, further work will become extremely difficult, or even stop altogether.

Doing work do not neglect personal protective equipment (canvas gloves, sturdy work boots). Working with a hammer drill, jackhammer, grinder do not be lazy to wear safety glasses otherwise, a viewing hole in the garage can be expensive.

And finally work with a partner... Even if his partner has red pigtails and is twelve years old! The tool will give or bring water. You don't need much strength for this, and you will learn to work! And if trouble happens, he can call for help.

The experience of building a viewing pit (video)

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