CLC Blocks in Pakistan: Benefits, Price and Suppliers

Muhammad Hammad Rafique

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Advancements in the construction industry have enabled us to improve our living standards. One such trend is the use of CLC blocks in construction. CLC blocks stand for Cellular Lightweight Concrete Blocks and sometimes it’s called fly ash bricks in Pakistan. As the name implies, CLC is an advanced shape of concrete blocks with more benefits and better properties.

In this guide, we will be discussing the manufacturing process of CLC, its benefits, and comparison with the clay bricks. This article will also focus on a pricing comparison of CLC with clay bricks. After reading this guide, you will have an idea about the cost difference between CLC blocks and bricks, their advantages, and decide for yourself which material you want for your construction project.

What are CLC Blocks?

CLC blocks are made from lightweight concrete or foam concrete. CLC is a lightweight concrete that is created by mixing cement and fly-ash with pre-formed foam. CLC concrete is also known as foam concrete. Around the world, CLC blocks are also known as foam concrete blocks or foamcrete blocks. In Pakistan, these blocks are commonly known as CLC blocks in the construction industry.

CLC Blocks 1

How are CLC Blocks produced?

CLC blocks are formed by mixing cement, fly ash, sand, water, and foaming agent. There are two types of foaming agents used while making CLC blocks. They can be protein-based or synthetic. Each has its identical properties and affects the overall strength of the CLC blocks. However, the proportion of other raw materials also determines the properties of the CLC blocks. The attributes that can be changed by altering the raw materials’ percentage are strength, thermal conductivity, and durability. To obtain a required density and variance of the CLC blocks, an appropriate mix is selected, and the percentage of the raw materials is changed.

Manufacturing Process

To know about CLC blocks in detail, it is important that we understand the manufacturing process. It is possible that there are some variations in the manufacturing process from one place to another, but the basic process explained here is the same. The manufacturing process is explained in the steps below.

  1. First of all, cement, sand fly ash, and water are added to a concrete mixer and mixed thoroughly to form concrete slurry.
  2. Water is added to the foaming agent and mixed in a foam generator to form aqueous foam.
  3. The aqueous foam and the concrete slurry are mixed together in the mixer to form the CLC.
  4. After the CLC slurry is formed, it is checked for density and other properties. If the results are accurate, the slurry is drained into trollies.
  5. The slurry is then poured into the assembled molds for drying. The shape and volume of the molds can be different and changed as per the order/batch details. The slurry is allowed to settle for at least 24 hours.
  6. The blocks are then curated. As the curating time increases, the strength of the CLC blocks also increases. It is important to note that the average strength of the CLC blocks when aluminum is used as a foaming agent is far greater than a protein-based foaming agent. The increase in the strength of CLC blocks with the curating time is also more than the increase in the strength of the conventional clay bricks you use for construction.

Comparison with Clay Bricks

A research paper published by the well-reputed International Journal of Advance Engineering and Research Development showed the relationship between CLC blocks and conventional bricks over time. The strength gained by CLC blocks is far greater than the strength gained by the conventional bricks. If you are planning to buy CLC blocks for building your home, make sure you get blocks curated for 21 days. These blocks will give more durability to the building. Let’s look at some of the figures supporting the claim.

Average Strength of CLC Blocks & Conventional Clay Bricks after 7 Days
Material Load (kN) Area (mm²) Average Strength (N/mm²)
CLC Blocks (Protein Based) 36.59 17100 2.14
CLC Blocks (Aluminum Based) 38.81 17100 2.27
Conventional Clay Bricks 39.84 17100 2.33
Average Strength of CLC Blocks & Conventional Clay Bricks after 14 Days
Material Load (kN) Area (mm²) Average Strength (N/mm²)
CLC Blocks (Protein Based) 78.157 17100 4.57
CLC Blocks (Aluminum Based) 61.56 17100 3.6
Conventional Clay Bricks 64.98 17100 3.8
Average Strength of CLC Blocks & Conventional Clay Bricks after 28 Days
Material Load (kN) Area (mm²) Average Strength (N/mm²)
CLC Blocks (Protein Based) 153.33 17100 8.96
CLC Blocks (Aluminum Based) 96.67 17100 5.65
Conventional Clay Bricks 100 17100 5.84

From the above figures, it is obvious that CLC blocks are far more durable than conventional clay bricks. You only build a home once in your life. Why use clay bricks when you can afford the CLC blocks. CLC blocks will make your home more durable and protect the inhabitants for a long period.

Advantages of CLC Blocks

Lightweight: CLC blocks are lightweight. Their density is 300-1800kg/m3. The weight is 3 times less than the conventional clay bricks.

Reduction of Dead Load: CLC blocks reduce the dead load. When you want to add extra floors, or you have unstable ground conditions, the application of normal concrete blocks or clay bricks is limited. CLC is lightweight and thus reduces the dead load. Lightweight structures are also appreciated in earthquake-prone areas. Dead load is also reduced because aggregates are not required in the manufacturing of the CLC blocks.

Insulation: CLC blocks are better insulators than conventional bricks. A house build using CLC blocks will have lower electricity and heating bills in summer and winter respectively. CLC blocks are also known for thermal insulation. As they are composed of 30-35% air, heat transfer from outside to inside is greatly reduced. CLC blocks will keep your home cool during the harsh summers.

Eco-friendly: CLC is an eco-friendly product. It will not damage the environment like bricks. Fly-ash is an industrial waste material. Unlike the bricks, the CLC manufacturing process does not release any harmful effluents into the ground, water, and air. CLC is used for making partitions, which in turn reduces deforestation as plywood is not used.

CLC Blocks 2

Savings in Structural Foundations: When CLC blocks are used for making homes, you also get to save in structural foundation. CLC blocks are lightweight; hence the load transferred to the foundation reduces. This, in turn, leads to less steel being used in making the structural foundation, which results in huge savings.

Paint/Plaster Saving: Only a thin layer or single coat of paint will be good with CLC blocks. You can save a handsome amount of money on paint/plaster as well.

Fire Protection: CLC blocks are far superior when it comes to protecting your home from fire. The air embedded in the CLC plays a vital role in giving CLC blocks a higher fire rating. The thickness of a CLC wall is less than the brick wall, and it can offer up to 4 hours of fire rating without releasing any toxic fumes during an unfortunate event of fire.

Low Water Absorption: Low water absorption helps to reduce the cracks in the wall. It gives more durability to your home.

Quick Installation: CLC blocks are lightweight and thus easy to install. The construction time and effort reduce significantly when you are going for CLC blocks instead of conventional bricks. If you are doing construction in a hilly area, CLC blocks are recommended as you don’t need expensive transportation to deliver the heavy bricks.

Earthquake Resistance: As CLC blocks are lightweight, they are very reliable in earthquake-prone areas.

Uses of CLC Blocks

CLC blocks can be used in the following ways

  • Acoustic Construction
  • Precast exterior walls
  • Roof insulation
  • Waterproofing
  • Adding more floors to existing structures
  • Green construction
  • Construction material for high-rise buildings

Sizes Available in Pakistan

The common sizes (mm) (L x W x H) being available in Pakistan are mentioned below.

  • 600 x 100 x 200
  • 600 x 150 x 200
  • 600 x 200 x 200

Pricing Comparison

Now that you know about the benefits and uses of CLC blocks, it is time to compare the prices with conventional clay bricks. We know that CLC is costly, but it is your home’s safety and your family we are talking about. Owning a home in Pakistan is a dream of millions, and therefore you must not make any compromises while building one. We suggest using CLC blocks instead of conventional bricks; you can reap all the advantages we discussed above. The built quality of clay bricks in Pakistan is going down day by day. The reasons being: low-quality sand is used in the manufacturing process, quality is reduced to meet the high demand, and overall low quality due to high salt content in the sand.

Per Square Feet Construction Cost

The following table will compare the price of building a home with conventional bricks and the CLC bricks.

Fly ash blocks

Costing Details/Sqaure Feet (PKR-RS)
Construction Details Without Basement With Basement
Regular Brick Structure 1400-1500 1700-1800
Frame Structure with Bricks 1600-1700 2000-2100
Frame Structure with CLC Blocks 1900-2000 2200-2300

Let us now calculate by taking the example of the 10-Marla and 1-Kanal area.

10-Marla Construction Cost

When building a 10-marla home, the covered area is usually 3400 square feet without basement and 4400 with basement. The table below mentions the average cost for building a 10 Marla house.

Costing Details/10-Marla (PKR-RS)
Construction Details Without Basement (3400 sq. ft) With Basement(4400 sq. ft)
Regular Brick Structure 4,930,000 7,700,000
Frame Structure with Bricks 5,610,000 8,800,000
Frame Structure with CLC Blocks 6,290,000 9,680,000

1-Kanal Construction Cost

For a 1-Kanal home, the covered area without a basement is 5400 square feet, and with a basement, it is 8100 square feet. Cost estimation is given below.

Costing Details/1-Kanal (PKR-RS)
Construction Details Without Basement (5400 sq. ft) With Basement(8100 sq. ft)
Regular Brick Structure 7,830,000 141,017,500
Frame Structure with Bricks 8,910,000 16,200,000
Frame Structure with CLC Blocks 9,990,000 17,820,000

If you analyze the tables above, you will note that frame structure with bricks is around 15-20% costly than regular bricks structure and CLC blocks with frame structure are 25% costly than regular bricks structure. You will be paying a lot more, but you will also be getting many benefits by using CLC blocks. The final call is in your hands.

Please note that the costs mentioned above are estimated according to the market trends. Expect some fluctuation in the cost from time to time. The cost may change with respect to government policies and taxes as well. The rates can also vary from one city to another in Pakistan.

Final Words

Now that you know everything about CLC blocks, their benefits, uses, and pricing, making your final decision will be easier. If you have the budget, go for CLC blocks as you will be getting a lot of benefits from them and playing your part in saving Pakistan’s environment.

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