Construction of a garage is an important stage on which the safety of your car and the comfort of servicing it depend. The choice of the main wall material is the foundation of the entire project, determining not only the budget, but also the speed of construction, thermal insulation and durability of the structure. The market offers many options, from classic brick to modern composite materials, and it is easy for a beginner to get confused by the abundance of characteristics.
In this article we will look in detail at which blocks are best for a garage in different climatic conditions and with different budgets. You will learn about the advantages and disadvantages of each type, the features of masonry and nuances that builders are often silent about. The correct choice of material will avoid problems with dampness, freezing of walls and unnecessary heating costs in the future.
Before purchasing the first batch of material, it is necessary to clearly define the purposes for operating the building. Will it be just a parking space or a full-fledged workshop with heating? The required thermal conductivity walls and the need for additional insulation. It is also important to consider the bearing capacity of the soil, since the weight of different types of blocks differs significantly.
Criteria for choosing material for garage walls
When designing a garage, value for money becomes a (primary) consideration. However, saving on the walls can lead to disastrous consequences, such as the formation of condensation, which will quickly destroy the car body with corrosion. Therefore, when choosing, you need to pay attention to a set of indicators, and not just to the cost of one element.
The key parameter is compressive strength. For a one-story garage with a wooden or light metal roof, the requirements are lower than for a building with an attic or a heavy natural tile roof. Also critical frost resistance material, designated F. In an unheated garage, the walls will freeze completely, and the freeze-thaw cycle can quickly destroy a low-quality unit.
⚠️ Attention: Never use blocks for the external walls of the garage that are not intended for facade work or do not have a sufficient frost resistance coefficient (less than F35), otherwise the structure may lose its load-bearing capacity after several winter seasons.
Another important aspect is hygroscopicity, that is, the ability of a material to absorb moisture. The garage is an area of high humidity due to temperature changes and possible water ingress from the car. A material with high water absorption will require mandatory and high-quality external finishing, otherwise it will work like a sponge, creating dampness inside the room.
Aerated concrete blocks: advantages and risks
Aerated concrete (autoclaved aerated concrete) is often chosen for its ideal geometry and high thermal insulation properties. This material is produced in a factory, which guarantees accurate dimensions and absence of defects in shape. Walls made of aerated concrete are erected very quickly, especially if special glue is used rather than cement mortar.
However, the material has a significant drawback - high hygroscopicity. Aerated concrete is capable of absorbing up to 30% of moisture from its own weight, which requires mandatory hydrophobic protection of the facade. If you are planning an unheated garage, moisture that gets into the pores of the block in the fall will freeze in the winter and can lead to microcracks.
- 🏗️ High construction speed due to large block sizes.
- 🔥 Excellent fire resistance - the material does not burn and does not support combustion.
- ❄️ Low thermal conductivity allows you to build thinner walls without heat loss.
- 💧 Requires mandatory steam and waterproofing.
Why does a gas block crack?
Aerated concrete blocks have low bending strength. Even with a slight shrinkage of the foundation (only 2 mm per linear meter), cracks may appear in the wall. Therefore, a powerful reinforced strip foundation is critical for aerated concrete.
Aerated concrete is suitable for a garage if you are ready to make a high-quality exterior finish, for example, siding with a ventilated gap or plaster with vapor permeability. Otherwise, using this material may be a mistake. It is also important to consider that attaching heavy shelves and equipment to an aerated block requires special dowels.
Foam concrete: a budget option with nuances
Foam concrete is often confused with aerated concrete, but these are different materials with different production technologies. Foam blocks harden under natural conditions, which often leads to unstable geometry and shrinkage after laying. But they are much cheaper and less susceptible to moisture due to their closed pore structure.
The main problem with foam concrete on the market is the huge amount of low-quality handicraft products. Blocks made with improper technology may crumble in your hands and may not have the declared strength. When purchasing, be sure to ask for certificates and check the material visually: the surface must be free of chips and the color must be uniform.
Despite the risks, foam block remains a popular choice for outbuildings. If you find a trusted manufacturer, you can get a warm and cheap garage. However, fastening gates and heavy structures will require the use of chemical anchors or brick embedded parts in the hanging areas.
Expanded clay concrete: the golden mean of strength
Expanded clay concrete blocks are considered one of the best solutions for garage construction. They combine strength similar to brick and good thermal insulation properties thanks to the foamed clay filler. This material does not burn, does not rot and has excellent frost resistance.
Unlike aerated concrete, expanded clay block is less hygroscopic and holds fasteners better. You can safely hang heavy workbenches, tool shelves, and tire storage systems on such walls without fear that the dowel will fly out. The density of the material allows you to build two-story garages or make a full-fledged attic.
| Characteristics | Aerated concrete | Expanded clay concrete | Foam concrete |
|---|---|---|---|
| Strength (kg/cm²) | 25-50 | 50-150 | 15-35 |
| Thermal conductivity | 0.11 W/m°C | 0.27 W/m°C | 0.20 W/m°C |
| Frost resistance | F50-F100 | F50-F100 | F15-F50 |
| Water absorption | High | Average | Low |
The only disadvantage of expanded clay blocks is their appearance and geometry. Often the blocks have chips and uneven edges, which requires a thicker layer of mortar or the use of plaster to level them. This increases the consumption of materials and work time, but the final design is more monolithic and reliable.
Cinder block: cheap versus environmentally friendly
Cinder block is perhaps the most famous material for Soviet-built garages. It is made from metallurgical waste (slag) and cement. The main advantages are low price and high density. However, in modern construction it is treated with caution.
The main problem with cinder block is its background radiation and possible toxicity if harmful impurities were used during production. Before purchasing a large batch, be sure to request a radiation certificate. In addition, old cinder blocks often have voids that can erode over time, turning the block into dust.
⚠️ Attention: Do not use cinder blocks made more than 20-30 years ago, even if they are on sale. The cement binder in them has already exhausted its service life, and the bearing capacity of such blocks is extremely low.
If you still choose a cinder block for your garage, give preference to solid options marked M100 and higher. They are heavier, but will provide the necessary strength to the walls. It is also worth considering that cinder block is very cold, and a garage made from it will require serious insulation if you plan to work there in the winter.
Polystyrene concrete and wood concrete: modern solutions
Polystyrene concrete is concrete filled with polystyrene foam granules. This material has record low thermal conductivity and low weight. This can be an excellent solution for a garage, since it does not require additional insulation even in cold regions.
Arbolite (wood concrete) consists of cement mortar and wood chips. This is an environmentally friendly material that “breathes”, creating a favorable microclimate. However, both of these materials have low compressive strength compared to expanded clay concrete and require protection from direct precipitation and ultraviolet radiation.
☑️ Checking blocks before purchasing
The use of these materials is justified if the garage is being built in a difficult climate and heat preservation is a priority. But remember that fastening heavy structures into polystyrene concrete and wood concrete requires special fasteners, since ordinary dowels may not withstand the load.
Foundation and features of block laying
The choice of blocks dictates the requirements for the foundation. Lightweight gas blocks and foam blocks forgive small soil movements less than heavy bricks, but they are more sensitive to uneven settlement. For a block garage, the optimal solution would be strip foundation, buried below the freezing point of the soil.
The first row of masonry is the most important. It must be laid out on a cement-sand mortar and carefully leveled. Any mistake in the first row will cause the entire wall to warp. Waterproofing (roofing material or bitumen mastic) must be laid between the foundation and the first row of blocks.
Proportions of mortar for masonry:Cement M400 - 1 part
Sand - 4 parts
Water to a plastic consistency
Plasticizer - according to instructions
To increase the strength of the wall, it is recommended to perform reinforcement every 3-4 rows. Reinforcement with a diameter of 8 mm or a special mesh is placed in a layer of mortar or glue. This is especially true for aerated concrete and foam concrete, preventing the appearance of cracks.
Use a special notched trowel and glue for laying gas blocks. This will allow you to make a seam with a thickness of 2-3 mm, which will eliminate cold bridges and save material compared to cement mortar.
FAQ: Frequently asked questions
Is it necessary to insulate a garage made of blocks if it is not heated?
If the garage is not heated, insulating the walls does not make much sense from an energy saving point of view, since there is nothing to retain heat. However, insulation may be required to prevent condensation from forming on the internal walls during temperature changes, which will protect the car from corrosion.
How thick should a garage block wall be?
For a one-story garage without an attic, the optimal wall thickness made of expanded clay concrete or aerated concrete blocks is 300-400 mm (one block). This ensures sufficient load-bearing capacity and acceptable thermal insulation.
Is it possible to build a garage out of blocks in winter?
Laying on cement mortar can be carried out at temperatures down to -5°C with the addition of anti-frost additives. Laying with aerated concrete glue cannot be carried out in winter, as the water in the glue will freeze before it has time to set, and the seam will be fragile.
What is the best way to decorate the facade of a garage from blocks?
The best options: plaster followed by painting, siding with insulation, facing bricks or corrugated sheets. The main requirement is that the finishing material must protect the blocks from direct rain and snow, especially if it is aerated concrete.
What is cheaper: building a garage out of blocks or buying a metal one?
A metal garage (shell) is cheaper only at the stage of purchase and installation. A block garage is more expensive to build, but it is more durable (50+ years versus 10-15 years for metal), retains temperature better and protects against burglary. In the long run, blocks are more profitable.
Expanded clay concrete blocks are the optimal choice for most private garages: they combine strength, reasonable price and good thermal insulation, without requiring complex finishing.