The construction of a permanent garage for a car is an investment in the safety of the vehicle and personal space. Among the many building materials, foundation wall blocks (FBS) occupy a special place due to their strength and speed of installation. Many car owners consider this option as an alternative to classic brick or foam concrete, not realizing the specific nuances of working with heavy products.
Usage reinforced concrete blocks allows you to create a structure that will last for decades, withstanding the aggressive influence of the external environment. However, to prevent the structure from turning into a “cold warehouse” with mold, it is necessary to strictly follow the installation and waterproofing technology. In this article we will look at how to competently design and build a garage, avoiding common beginner mistakes.
Advantages and disadvantages of using FBS for a garage
The main trump card of this material is industrial strength. The blocks are produced in a factory, subject to strict quality control of concrete and reinforcement frame. This guarantees the absence of hidden defects, which are often found in handicraft building materials. The service life of such products is estimated at decades, which makes them ideal for long-lasting buildings.
However, there is a downside to the coin. The high thermal conductivity of concrete requires mandatory insulation of the walls, otherwise in winter it will be cold inside and condensation will form on the walls. It is also worth considering the need to use lifting equipment, since it is impossible to manually move products weighing from 300 kg to 2 tons.
- 🏗️ Construction speed: The walls of the garage rise in a matter of days, as one block replaces a masonry of dozens of bricks.
- 🛡️ Stability: the material does not rot, does not rust and is resistant to rodents and insect pests.
- 💰 Cost: the price per cubic meter is often lower than quality ceramic bricks, although the final estimate may increase due to crane rental.
⚠️ Attention: FBS blocks are highly hygroscopic. Without high-quality external waterproofing and blind area, moisture will rise through the capillaries of the concrete, destroying the structure from the inside and creating dampness inside the room.
It is important to note that for a garage, not only the strength of the walls is important, but also the possibility of organizing an inspection pit. FBS blocks make it easy to combine different types of foundations, creating a reliable foundation for heavy equipment or racks with spare parts.
Preparing the project and choosing block sizes
Before purchasing materials, it is necessary to clearly determine the dimensions of the future structure. A standard one-car garage typically measures 3 by 6 meters or 4 by 6 meters. When using FBS, it is important to consider the length of the products to minimize the amount of cutting and adjustment. The most common blocks are 880, 1180 and 2380 mm long.
Design must include calculation of the load on the foundation. If you plan to install a second floor or a heavy roof with concrete floors, blocks of greater density and width will be required. For a standard one-story garage with a light roof made of corrugated sheets or metal tiles, blocks with a width of 300-400 mm are sufficient.
| Marking | Length(cm) | Width(cm) | Height (cm) | Weight (tons) |
|---|---|---|---|---|
| FBS 9.3.6 | 88 | 30 | 58 | 0.35 |
| FBS 12.3.6 | 118 | 30 | 58 | 0.46 |
| FBS 24.3.6 | 238 | 30 | 58 | 0.97 |
| FBS 24.4.6 | 238 | 40 | 58 | 1.30 |
When creating a layout, try to avoid vertical seams in the same row. The ideal layout resembles brickwork, where the block of the upper row overlaps the junction of the two lower ones. This ensures the solidity of the structure and uniform distribution of loads.
Excavation and foundation installation
Construction begins with marking the site and digging a trench. The depth of the foundation should be below the freezing point of the soil in your region so that heaving forces do not push the structure out in winter. For the central part of Russia, this value is usually 1.2–1.5 meters. The bottom of the trench is carefully compacted and covered with a layer of sand and crushed stone.
A monolithic reinforced concrete strip is poured onto the prepared cushion or ready-made slab foundations (SF) are installed. The use of FL slabs significantly speeds up the process and creates a perfectly flat area for installing the first blocks. The width of the foundation should be 20-30 cm wider than the FBS blocks themselves to create stable support.
☑️ Preparing the base
After installing the slabs or hardening the tape, the surface is covered with waterproofing. Typically, roofing felt or bitumen mastic is used. Only after this can you begin to lift and install the first blocks. The masonry mortar is prepared from M400 or M500 cement and sand in a ratio of 1:3.
Wall masonry technology and reinforcement
Installation of walls made of FBS blocks is impossible without the use of a crane or truck crane. The work is carried out sequentially: first, the corner elements are laid out, then the spans between them are filled. Each block is installed on a layer of cement mortar 2-3 cm thick. Vertical joints are also filled with mortar.
To increase seismic resistance and overall rigidity of the structure, it is recommended to lay reinforcing mesh or rods with a diameter of 8-10 mm between the rows of blocks. It is especially important to reinforce the first and last rows, as well as areas above window and door openings. Reinforced concrete lintels are installed here, which take on the load from the overlying masonry.
⚠️ Attention: It is strictly forbidden to leave voids in vertical seams. Incomplete filling with mortar leads to the formation of cold bridges and a decrease in the load-bearing capacity of the wall. Use vibrating the solution or bayoneting to remove air.
During the laying process, it is necessary to constantly monitor the horizontal and vertical rows using a level and plumb line. Even a slight misalignment of a few centimeters at a height of three meters can lead to problems when installing gates or installing the roof. If the block is installed crookedly, it must be immediately removed and repositioned before the solution sets.
The nuances of working with the solution
The mortar for laying FBS must be thick enough so as not to be squeezed out under the weight of the block, but plastic to fill uneven areas. In hot weather, it is recommended to slightly moisten the surface of the blocks so that they do not draw moisture from the cement mixture too quickly, which could lead to cracking of the joint.
Waterproofing, insulation and roofing
After the walls are erected and the floors (or rafter system) are installed, the stage of protecting the structure from moisture begins. The outer surface of the blocks is treated with bitumen mastic or covered with roll materials. This is a mandatory step, neglecting which will lead to dampness in the garage.
Insulating a garage using FBS is a matter of comfort. Concrete cools quickly, so to create a workshop or just a warm room you will need a layer of insulation. The best option is extruded polystyrene foam or mineral wool, fixed to the sheathing, followed by lining with corrugated sheets or siding.
- 🌡️ Thermal insulation: use slabs with a thickness of at least 50 mm for temperate climates and 100 mm for northern regions.
- 💨 Ventilation: In a concrete garage, supply and exhaust ventilation is required to remove exhaust gases and moisture.
- 🏠 Roof: For FBS garages, a pitched roof with a slope in one direction is often used, which simplifies installation and reduces cost.
To save money on insulation, you can use expanded clay by pouring it into the space between the internal cladding and the FBS wall, if the foundation design and the width of the walls allow.
Estimates and typical mistakes during construction
The financial component of building a garage from FBS consists of the cost of the blocks themselves, delivery, rental of a crane, cement mortar and waterproofing work. Often, beginners forget to include equipment rental in their budget, which can amount to up to 30% of the cost of materials.
One of the main mistakes is saving on the foundation. Trying to place heavy blocks on a weak foundation results in cracks and skewing of the gate. The construction of a blind area around the garage is also often ignored, which leads to flooding of the foundation with melt water.
Critical: Do not use blocks with visible chipped reinforcement or deep cracks. A damaged frame sharply reduces the load-bearing capacity of the element, making it unsuitable for load-bearing walls.A FBS garage is a “construction set” for adults, where the cost of a mistake is high. Accurate calculation, high-quality foundation and proper waterproofing are more important than the speed of laying blocks.
In conclusion, it is worth saying that a garage made of foundation blocks is a reliable and durable solution. If the technology is followed, it will last longer than the car itself that will be stored in it. The main thing is not to skimp on the quality of materials and not to violate proven construction standards.
Is an armored belt needed for a garage roof made of FBS?
Yes, installing an armored belt along the top row of blocks is highly desirable. It connects the structure into a single whole, distributes the load from the roof and allows you to securely fasten the Mauerlat for the rafters. Without an armored belt, a point load from the rafter legs can split the block.
Is it possible to build a garage from used blocks?
You can use used blocks, but with caution. They must be intact, without severe damage to the geometry and with intact hinges (if they are needed for installation). Often such blocks have dirt or waterproofing residues, which impairs adhesion to the mortar. They must be cleaned before use.
Which solution is best suited for laying FBS?
Cement-sand mortar grade M100 or M150 is considered optimal. You can use ready-made dry mixtures for laying foundation blocks, adding plasticizers to them to increase the elasticity and frost resistance of the joint.
How long does it take to gain strength before installing the floor?
The solution gains basic strength within 28 days, but further work (installation of lintels, roofing) can begin in 7-10 days under favorable weather conditions, when the solution reaches 70% of the design strength.