Construction of a garage is a critical stage that requires precise budget planning and the purchase of materials. One of the most popular questions when constructing a capital structure is determining the exact quantity building blocks. A garage measuring 5 by 6 meters is considered a standard solution, allowing you to comfortably accommodate one car and leave space for a workbench or shelving.
An error in calculations can lead to the fact that there is not enough material in the midst of work, or the excess will clutter the site for years. cinder block — the material is inexpensive, but its volume is significant, so ordering “by eye” is not economically feasible. In this article we will analyze the calculation method, taking into account the thickness of the walls, the presence of gates and windows, as well as the necessary reserve for fighting and pruning.
To begin with, it is important to decide on the project. From what foundation you have laid down and what ceiling height you plan will depend on the final figure in the estimate. We will consider the classic option with a wall height of 2.5–3 meters and standard masonry.
⚠️ Attention: Never order material exactly according to the calculated minimum. During delivery and unloading, the breakage ranges from 3 to 5%, and trimming of entire blocks for corners and openings is always required.
Choosing the type and size of cinder block
Before you start doing arithmetic, you need to clearly understand what kind of material you will use. On the building materials market, various types are often hidden under the general name “cinder block”. wall stones. The standard size of a classic cinder block is 390x190x188 mm. It is these dimensions that are most often taken as the basis for garage projects.
However, there are other variations, such as half blocks or blocks with a decorative front side. If you are planning an insulated garage, a wall thickness of one block (390 mm) may be excessive for the southern regions, but necessary for the north. At the same time, laying half a block (190 mm) will require mandatory insulation and cladding, which will increase overall costs.
It is important to consider the voidness of the material. The blocks can be solid or have a voidness of 20-30%. For load-bearing garage walls, the best option is one with moderate voids, which strikes a balance between thermal insulation and strength designs.
Calculation of perimeter and wall area
Basic math for a 5 by 6 meter garage starts with determining the perimeter. We add up the lengths of all sides: 5 + 6 + 5 + 6 = 22 linear meters. This is the length of the future foundation and the basis for calculating the number of rows of masonry. Next we determine the height of the walls. The standard height for a garage is 2.5 meters (13 rows) or 2.8–3 meters (15-16 rows).
The area of all walls without subtracting openings is calculated by multiplying the perimeter by the height. For a height of 2.5 meters, the area will be: 22 m × 2.5 m = 55 square meters. This is the “dirty” area from which you will later need to subtract gateway and, if provided for by the project, a window or gate.
Pay special attention to the corners. At the junction of the walls, the blocks can overlap each other, which slightly changes the geometry of the internal space, but has a slight effect on the external perimeter. The main thing is to accurately measure the external dimensions foundation, since it is along its edge that the first row of masonry will go.
Methodology for calculating the number of blocks
There are two main ways to determine how many pieces of material you will need. The first method is calculation by area. Knowing that for 1 square meter of a wall one block thick (390 mm) it takes approximately 12.5–13 pieces of standard cinder blocks (including seams), we can quickly get an approximate figure. However, this method is less accurate due to the variability in the thickness of the seams.
A more accurate method is calculation by rows. Divide the height of the wall by the height of the block plus the thickness of the seam. The standard block height is 188 mm, the seam is taken as 10 mm. Total height of one row: 198 mm. For a wall 2500 mm high you will need: 2500 / 198 ≈ 12.6, rounded up to 13 rows. Then we count the number of blocks in one row along the perimeter and multiply by the number of rows.
Don't forget about mortar joint. If you use glue or a special mixture with a thin seam (2-3 mm), the consumption of blocks will increase, since the rows will become thinner and more of them will be needed for the same height. The classic cement-sand mortar “eats” more height, but forgives errors in the geometry of the blocks.
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Accounting of openings: gates, windows and doors
A garage cannot exist without an entrance gate. The standard gate width for one car is from 2.5 to 3 meters, and the height is about 2.1–2.2 meters. The area of the gate opening must be subtracted from the total area of the walls, so as not to purchase extra building blocks.
If the project provides a separate gate (for example, 0.9 × 2.1 m) or a window for natural light, their area is also subject to deduction. However, experienced builders often recommend not subtracting small openings completely, but leaving this volume as a reserve for pruning and fight.
A lintel must be provided above the opening of gates and windows. It can be metal (angle, channel) or concrete. Blocks that formally should have stood at the location of the opening are often used to construct lintels or lay out gables if the roof is gable.
⚠️ Attention: When calculating the number of blocks, do not subtract the area of the armored belt if it is planned. A reinforced concrete belt will tie the structure together, but its volume is difficult to compensate for by trimming, so it is better to have a small supply of material.
Solution consumption and additional materials
The amount of cinder block is only half the equation. For high-quality masonry it is necessary solution. On average, 0.2–0.25 cubic meters of ready-made mortar are required per 1 cubic meter of masonry. For a garage 5 by 6 meters, the volume of masonry will be approximately 17–20 cubic meters (with a wall of one block), which will require ordering several tons of sand and dozens of bags of cement.
You will also need reinforcement to strengthen the masonry. Typically, a metal mesh or two reinforcement bars with a diameter of 6–8 mm are laid every 3–4 rows. This prevents cracks from occurring when shrinkage foundation and increases the fracture strength of walls.
Don't forget about waterproofing. Before laying the first row of cinder blocks on the foundation, 2 layers of roofing material or waterproofing must be laid. This will protect the hygroscopic material of the walls from moisture rising from the ground.
For laying cinder blocks, use special glue or cement mortar with the addition of a plasticizer. This will improve adhesion and make the seam thinner, which will have a positive effect on thermal insulation.
Final material calculation table
For convenience, we summarize the main data in a table. The calculation is given for a garage of 5x6 meters with a wall height of 2.5 meters and a wall thickness of one block (390 mm), taking into account a standard gate of 3x2.2 meters.
| Parameter | Meaning | Note |
|---|---|---|
| Garage perimeter | 22 linear meters | Without taking into account the thickness of the corners |
| Wall area (dirty) | 55 m² | Before openings |
| Gate area | 6.6 m² | Size 3×2.2 m |
| Net masonry area | 48.4 m² | Round up to 49 m² |
| Number of blocks (pieces) | ~640 pcs. | Without stock |
| Block volume (m³) | ~19 m³ | Including seams |
It is important to note that the data in the table is basic. The actual number of blocks for a 5x6 meter garage, taking into account the reserve for fighting and pruning, will be approximately 670–680 pieces. Rounding is always done upward, since purchasing additional material in small quantities later will be more expensive due to delivery costs.
How does the thickness of the seam affect the number of blocks?
The thickness of the seam directly affects the number of rows and solution consumption. With a 10 mm seam, fewer rows are included per meter of height than with a 5 mm seam. However, a thin seam requires a perfectly even block geometry, which is rare for a cinder block. Therefore, the standard calculation is carried out for a 10 mm seam.
Can I use used cinder blocks?
Using used blocks is possible, but requires careful sorting and cleaning of old mortar. Savings can be up to 40%, but labor costs for preparing the material will increase significantly, and the strength of the masonry may be lower.
Is it necessary to reinforce each row?
It is not necessary to reinforce each row and is not economically feasible. It is enough to lay reinforcing mesh or rods every 3-4 rows, and also always under and above window openings.
The optimal amount of cinder blocks for a 5x6 meter garage with a wall height of 2.5 meters is 670-680 pieces when laid in one block.
Frequently asked questions (FAQ)
How many pallets of cinder block do you need for a 5 by 6 garage?
A standard pallet holds 60 or 90 blocks (depending on the manufacturer and type of block). For a garage of 5x6 meters you will need approximately 7-8 pallets (at the rate of 670 pieces / 90 pieces ≈ 7.4). It is better to order 8 pallets, taking into account possible damage during transportation.
What brand of cement is best to use for masonry?
Cement grade M400 or M500 is optimal for laying cinder blocks. The solution is prepared in the proportion of 1 part cement to 3-4 parts sand. Using higher grades of cement unnecessarily will increase the cost of the work, and lower grades may not provide the required strength.
Do I need to wet the cinder block before laying it?
Yes, especially in hot weather. Dry cinder block quickly draws water from the cement mortar, which reduces adhesion and can lead to cracks. It is recommended to slightly moisten the blocks before laying, but not to wet them to the point of a puddle.
Which wall thickness is better: half a block or a block?
For a permanent garage where the car is planned to be stored all year round, it is recommended to lay it in one block (390 mm). A half-block wall (190 mm) will require mandatory insulation and external finishing, which in the end can be more expensive than building a thick wall right away.
How to calculate the amount of solution yourself?
For an approximate calculation, use the formula: multiply the volume of the masonry by 0.25. If the volume of the blocks is 19 m³, then about 4.7–5 m³ of solution will be needed. This is approximately 1.5–2 tons of dry mixture or the corresponding amount of sand and cement.