Recommendation points
- Elements of the inspection pit
- Feature of the device of the inspection pit
- Popular mistakes when building an inspection pit yourself
- Garage Pit Guide
- Other pit options
The article will tell you about how to properly arrange an inspection pit in the garage. You will learn about the features of this structure, popular errors and methods of their elimination. In addition, we will describe a step-by-step guide with photos for building a reinforced inspection pit..
The garage, with sufficient skill of its owner, is gradually turning into a service station, in which the car is repaired and serviced by caring master’s hands, and here you cannot do without arranging a viewing pit. Its structure is a rectangular longitudinal recess along the garage, 600–800 mm wide and as deep as an average human being. The length of the pit is determined by local conditions, but usually they try to make it as long as possible.
Elements of the inspection pit
Despite the apparent simplicity, the garage pit has characteristic features that must be understood in advance:
- Waterproofing (GI). An unconditional and obligatory hidden element, neglect of which is fraught with the fact that the pit will be impossible to use. The main problem of any pits and cellars is dampness: a car standing over a damp pit will itself become damp and rot.
Note.The groundwater level (GWL) can become an obstacle to the construction of a pit, since a flooded tank is an unacceptable structure for a garage.
- Power loop along the upper perimeter. Usually it is made from a corner to which reinforcement, mesh or simply “tails” are welded, which are launched into the reinforcement of the screed. This steel frame is needed to keep the pressure from the car in dynamics and statics. Without it, the wheels will simply push through the tie (which is rarely thicker than 50 mm) and it will collapse and fall into the pit. The steel contour also serves as a support for the jack and a place for laying the overlapping board.
- Niches. They give 200% more convenience in work. The more there are, the more convenient it is to work. Sufficient size – height 300–400 mm, depth 150–250 mm, length 400–500 mm. Usually, a maximum of 4 niches are made for a pit for a passenger car – approximately under each wheel.
- Additional stops. In the area of the wheels, when installing the power circuit, you can lay additional I-beams or channels (90–120 mm high) for the convenience of displacing the jack in height. Practice has shown that such manipulations in the hub area are a frequent need..
- Lighting. Pros know that the light in such pits must be powered from 36 volts. This excludes the possibility of ignition of fuel vapors and fuels and lubricants. When powered by 220 volts, a short circuit or a broken lamp can cause an accident, since it is rather difficult to quickly get out of a hole blocked by a car.
An insignificant feature is the staircase, the steps of which can be made monolithic, at the same time with the walls. Such a march is done most often in large garages with pits over 5 m in length. In a private household, in order to save space, ordinary ladders are used..
Feature of the device of the inspection pit
When designing an inspection pit for your own needs, focus on the convenience of working for yourself. First of all, this is the height of the working space or the depth of the pit. Here they are divided into two types:
- “Standing”. Designed for standing, full-length work.
- “Sedentary”. The operations are performed while sitting on the transverse seat. It can be installed on rollers, and run guides along the walls and easily navigate the pit. This method saves 500-600 mm depth and wall material.
In both cases, the edge of the pit should be approximately at the level of the master’s shoulder. This principle does not affect the design, only the depth.
Popular mistakes when building an inspection pit yourself
We will consider the shortcomings in the simplest version with brick walls:
- Floor concreting in front of the walls. The bulk of the screed or recumbent floor slab should be laid after the first rows have been erected. In other words, the slab should be inside the walls, not the walls on the slab. The slab inside will hold the load from the ground and additionally insure against deformations of the “box”. For walls, it is enough to make a mini-foundation 60-80 mm.
- Pit without screed. Making this mistake, the pit is made of stone or concrete, and the screed is not made out of economy or is postponed “for later”, that is, forever. The best solution is to make a tie in order to tie the power circuit of the pit, even if there is no special need for it.
- Disregard for ground strength. Often this mistake becomes fatal – movements at a depth below the bottom of the garage foundation are not felt on the surface. By removing the soil from the pit, a person violates its natural structure, and the soil seeks to fill the sinus (this is its natural property). Therefore, use all available reinforcement means – masonry mesh, armored belt, embedded parts, anchors.
- Neglecting reinforcement. Underground structures should be reinforced twice as thick as aboveground ones. The argument for stable soil is complacency, as soil behavior is unpredictable and can change due to climatic conditions. In other words, the soil may begin to press on the walls – in this case, the reinforcement will save the position every 2-3 rows with the obligatory strapping of the corners.
Garage Pit Guide
In this part of the article, we will talk about how to build a pit with your own hands, or rather, about the sequence of work. The “box” is proposed to be made by laying in a half-brick with reinforced concrete armored belt. This will be the maximum gain option..
1. Remove the soil. Pit dimensions: length – based on the possibilities of the garage; width – internal dimension (700 mm) plus one brick 200 mm. Total 1100 mm. In a mini-trench under the foundation of the walls, lay waterproofing and concrete. Release reinforcement from the extreme edge of the foundation to connect with the armopoyas.
2. Cover the pit with waterproofing. Several layers of polyethylene, or a special film. The ideal option is a PVC membrane. It is easily soldered with a hairdryer and creates volumetric corners..
3. Tie vertical and horizontal rods Ø 10–14 mm to the reinforcement outlets so that a mesh with a cell of approximately 150×150 is obtained. It should be a rigid one-layer space frame located in a 100 mm bore between the masonry and the ground covered with waterproofing.
4. The masonry of the walls can be raised by 3-4 rows, necessarily tying it with a masonry mesh, and the floor slab can be concreted. You can bring the masonry out to the end, simultaneously laying out niches, and then concreting the floor.
5. As the masonry progresses, the sinus can be concreted every 500-700 mm.
6. After the mortar and concrete have dried, the power circuit can be installed. It is cooked from a corner and installed on top of the masonry. Weld reinforcement outlets or embedded parts to the corners.
7. Then tie the screed mesh to the embedded parts and concrete the garage floor.
8. Structures should provide ventilation for 21 days.
We can say with confidence that a pit built using this technology will withstand any heaving of the soil, will not leak and will not get damp.
Other pit options
On stable dry soils, for example, when the garage is located on a mountain, you can not make a powerful armored belt and arrange a simpler solution. This can be a thin-layer concreting “slip formwork”.
This is called concreting only conditionally – rather, it is a method of applying a thick layer of plaster, which is needed to strengthen the soil cut.
Instead of laying out a stone one, you can make an all-metal tank. This is a completely viable option if you have the material and the ability to hermetically cook the metal..
An absolute guarantee of protection against flooding, but the metal itself must be reinforced with ribs and protected from moisture. Such a “glass” is simply installed in the pit and the sinuses are concreted. An unconditional plus – you can not tie the container to the screed.
There is no particular difficulty in building a garage pit. The main thing is to clearly understand your needs and measure them with the capabilities of the garage. In all other respects, you can rely on the materials of this article, created on the basis of the experience of many masters..
