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CLC Blocks Complete Guide: Cost, Benefits and Sizes

CLC Blocks

The construction industry in Pakistan is booming; newer and innovative technologies are being introduced, making properties safer and better. Likewise, rates of construction materials, such as traditional bricks, are also increasing, making it difficult for individuals to construct a full-fledged home. 

But now, thanks to the advent of CLC blocks, the cost of constructing a grey structure has been significantly reduced. However, not many contractors and homeowners know about this. That is why we have covered every aspect of CLC blocks in this comprehensive guide on CLC Block cost, benefits, and sizes.

What are CLC Blocks?

CLC Blocks

CLC stands for Cellular Lightweight Concrete Blocks. These are commonly known as fly ash blocks or foam concrete blocks. These blocks are made with fly ash, water, sand, cement, and foaming agents.  These blocks are used to construct grey structures. Although these blocks aren’t known for being used in load-bearing structures, their strength can be improved by increasing their thickness. 

CLC blocks can thus be used for border, exterior, and interior walls. These blocks have been utilized for diverse applications worldwide for the past six decades. They are fire and insect-resistant, low-maintenance, long-life, and seismic-resistant blocks.

How are CLC Blocks made?

CLC blocks are made by combining cement, fly ash, and pre-formed foam. To create foam concrete, stable, pre-formed foam that is produced locally is injected into this slurry. Cellular lightweight concrete or foam concrete is used to make CLC blocks. It is simple to install, nail, drill, and cut the blocks for conduits and pipelines. Fly ash/sand, cement, and dust protein-based foaming agents are the primary raw materials for creating CLC blocks. 

To make CLC blocks,

  1. Cement, sand, fly ash, and water are first added to a concrete mixer and properly mixed to create a cement slurry.
  2. Water is combined with the foaming agent in a foam generator to create aqueous foam.
  3. The concrete slurry and aqueous foam are combined in a mixer to make CLC.
  4. The CLC slurry is created, and its density and other characteristics are evaluated. The slurry is emptied into trollies if the findings are reliable.
  5. The completed moulds are then filled with the slurry to dry. According to the order/batch information, the moulds’ shape and volume can be altered. The slurry must be given at least 24 hours to settle. 
  6. Then, the blocks are curated. The power of the CLC blocks likewise grows as the curation time does. It is significant to note that when aluminium is utilized as a foaming agent, the average strength of the CLC blocks is significantly higher than when a protein-based foaming agent is used. 

The strength of CLC blocks increases with curing time, but it does so more quickly than the strength of the regular clay bricks you use in building.

Why Use CLC Blocks Instead of Bricks?

The common question is why use these blocks instead of traditional red bricks. CLC blocks are durable, lightweight, and much cheaper than red bricks. Using these blocks in the construction of your property ensures its longevity and durability and is lighter on your pocket. 

What are the Types of CLC Blocks?

There are two types of CLC blocks: protein-based and synthetic. The main differences between the two varieties are strength, durability, and heat conductivity. By altering the ratio of raw elements in their composition, you can increase their strength and durability.

What are the Benefits of CLC Blocks?

CLC Blocks are more cost-effective, durable, and long-lasting than traditional bricks. Here’s how they are better:


CLC blocks are ideal for thermal insulation, particularly in the summer. These blocks’ design allows them to effectively block heat transfer from the environment outside to the interior. These blocks keep homes and structures cool, especially in warm summer climates. As a result, you can reduce your summer electricity costs. Similar to how they cut summer heating costs, these blocks are effective insulators during the winter.

Dead Load Reduction

CLC blocks lessen the dead load. The use of regular concrete blocks or clay bricks is limited when you wish to construct additional storeys or when the ground is unstable. Because CLC is lightweight, the dead load is decreased. In regions that are susceptible to earthquakes, lightweight constructions are highly valued. Because aggregates are not used to produce CLC blocks, dead load is also decreased.

Fire Protection

CLC Bricks provide excellent fire safety. CLC block provides fire endurance for heat transmission for 4 hours with a wall thickness of merely 100mm and a wall weight of 1000 kg/m3 without emitting hazardous gases.

Lightweight Blocks

CLC blocks are less heavy than traditional bricks. The density of these bricks ranges from 300 kg/m3 to 1800 kg/m3. In addition, a conventional red brick has a density of between 1800 and 3400 kilograms per square meter.


CLC is a sustainable product. Unlike bricks, it won’t harm the environment. An industrial waste product is fly ash. Unlike brick manufacturing, CLC does not discharge hazardous waste into the soil, water, or air. Deforestation is decreased since plywood is not utilized while creating partitions with CLC.

Saves Installation Time

CLC blocks are quick and simple to erect and take little time. These blocks require less energy to install since they are lightweight. Utilizing CLC blocks dramatically reduces installation time and effort.

Low Water Absorption

Water pockets exist in CLC blocks that are not connected by their structure. As a result, they are less water-absorbing than conventional bricks. Less water absorption consequently lowers the chance of wall fractures.

Enhances Carpeted Area

As an engineered block, a CLC block is available in any thickness. The consumer receives an extra 2% to 3% of carpet area by using bricks that are 150 mm thick rather than bricks that are 9 inches thick. More money is saved due to the increased carpet area than was spent on bricks. 


CLC blocks come in various sizes and can be easily cut and shaped to fit specific construction needs. This versatility allows architects and builders to create customized designs.

Earthquake Resistance

Because of their minimal weight, CLC blocks are ideal for places with excellent seismic rates. As a result, these blocks offer a sturdy housing construction that can withstand a devastating earthquake better than regular bricks.


Despite their lightweight nature, CLC blocks are highly durable and can withstand environmental stressors, including moisture and temperature fluctuations.

Moreover, CLC blocks offer:

  • Paint protection: With CLC blocks, only a thin layer or single coat of paint will work. Additionally, you can save a sizable sum of money on paint and plaster.
  • Thermal Capabilities: CLC block interiors keep you warm on chilly winter days and cool in the summer, five times better than clay bricks and ten times better than RCC.
  • Cost-saving: Reductions in energy expenses associated with cooling. Ideal substance for use in cold storage facilities. Depending on the thickness of the plaster, even greater values may be attainable. 
  • Good sound insulation: Up to 37-42db sound reduction based on thickness. 

Comparison of CLC Blocks with Clay Bricks

To help you understand the benefits of CLC blocks clearly, we have created a table comparing them with traditional clay bricks.

Average Strength of CLC Blocks and Clay Bricks after 7 Days
MaterialLoad (kN)Area (mm²)Average Strength (N/mm²)
CLC Blocks (Protein Based)36.59171002.14
CLC Blocks (Aluminum Based)38.81171002.27
Conventional Clay Bricks39.84171002.33
Average Strength of CLC Blocks and Clay Bricks after 14 Days
MaterialLoad (kN)Area (mm²)Average Strength (N/mm²)
CLC Blocks (Protein Based)78.157171004.57
CLC Blocks (Aluminum Based)61.56171003.6
Conventional Clay Bricks64.98171003.8
Average Strength of CLC Blocks and Clay Bricks after 28 Days
MaterialLoad (kN)Area (mm²)Average Strength (N/mm²)
CLC Blocks (Protein Based)153.33171008.96
CLC Blocks (Aluminum Based)96.67171005.65
Conventional Clay Bricks100171005.84

What are the Sizes of CLC Blocks in Pakistan?

The following sizes of CLC blocks are available in Pakistan (LxWxH):

  • 24ʺ×8ʺ×8ʺ
  • 24ʺ×6ʺ×8ʺ
  • 24ʺ×4ʺ×8ʺ

What is the Cost of CLC Blocks in Pakistan?

CLC blocks are slightly more expensive than bricks but have many advantages. In 2020, the cost of each CLC block was between PKR 55 to 70. The new tariff of CLC blocks is anticipated to grow 20–30% in response to the increase in the cost of construction materials. 

As of 2023, the cost of CLC blocks is PKR 70-100. The size and quality of these blocks also affect how much they cost. 

Additionally, the costs differ depending on the Pakistani cities. However, the slightly higher costs of CLC blocks have advantages over the long run. Due to insulation, homes made using these blocks have lower electricity expenses. 

Compared to building a brick house traditionally, labour and transportation costs are also lower. As a result, CLC blocks are preferable to bricks if you have the money to do so.

Price Comparison Between CLC Blocks and Bricks

We have created the following table to help you anticipate the cost of making a grey structure with bricks and CLC blocks.

Cost Details/Square Feet (PKR) Details
Construction DetailsWithout BasementWith Basement
Regular Brick Structure1400-15001700-1800
Frame Structure with Bricks1600-17002000-2100
Frame Structure with CLC Blocks1900-20002200-2300

What are the Uses of CLC Blocks?

CLC Blocks are diverse materials that offer the following uses:

  • Acoustic Building
  • Roof Insulation
  • Waterproofing
  • Air-conditioned buildings
  • Precast exterior walls
  • Green construction
  • Construction material for high-rise buildings
  • Additional floors to the existing building
  • Low-cost houses

Construction Cost of a 10 Marla House with CLC Blocks

The covered space for a 10-marla house is typically 3400 square feet without a basement and 4400 with one. The typical price for constructing a 10-Marla house is shown in the table below.

DetailsCost Details of a 10-Marla House (PKR)
Construction DetailsWithout Basement (3400 sq. ft)With Basement(4400 sq. ft)
Regular Brick Structure4,930,0007,700,000
Frame Structure with Bricks5,610,0008,800,000
Frame Structure with CLC Blocks6,290,0009,680,000

Read More: 10 Marla House Construction Cost in Pakistan

Construction Cost of a 1 Kanal House with CLC Blocks

The covered area for a 1-kanal house is 5400 square feet without a basement and 8100 square feet with one. The estimated cost is provided below.

Cost Details of a 1-Kanal House (PKR)Details
Construction DetailsWithout Basement (5400 sq. ft)With Basement(8100 sq. ft)
Regular Brick Structure7,830,000141,017,500
Frame Structure with Bricks8,910,00016,200,000
Frame Structure with CLC Blocks9,990,00017,820,000

Read More: 05 Marla House Construction Cost in Pakistan

Looking at the tables above, you’ll see that CLC blocks with frame structure are 25% more expensive than standard brick construction and that frame structure with bricks is about 15-20% more expensive. Using CLC blocks will cost you significantly more money, but you will also gain a number of advantages. Your decision will ultimately be made.

Please be aware that the costs listed here are estimates based on current market conditions. You should occasionally expect the price to change. Regarding taxes and government laws, the price may also alter. In Pakistan, prices can differ from one city to the next.

Are CLC Blocks Sustainable?

CLC blocks are highly sustainable due to the following: 

  • Energy Efficiency: CLC blocks’ excellent insulation properties reduce the energy required for heating and cooling, reducing energy consumption in buildings.
  • Waste Reduction: Using fly ash, a waste product, as a raw material in CLC block production reduces the environmental impact and lowers the demand for natural resources.
  • Lower Carbon Footprint: The lightweight nature of CLC blocks reduces transportation emissions, as they are easier to transport. The lower energy requirements during manufacturing also result in a reduced carbon footprint.

The Bottom Line

CLC blocks are much more effective and cost-friendly than traditional bricks in the long-run. They may be a bit pricey, but they don’t wither away with time, offering you value for money. Utilize these blocks in constructing your home and see how your house stands the test of time.


What size are CLC blocks?

The standard size of CLC blocks is 24ʺ×8ʺ×8ʺ in Pakistan.

What are the benefits of CLC block?

CLC blocks are lightweight, fire resistant, eco-friendly, cost-efficient, and offer thermal insulation.

What are the sizes of construction blocks?

The size of construction blocks is 4” × 8” × 16”.

What is the size of a cement block?

The standard cinder block dimensions are 8 in. x 8 in. x 16 in.

How thick is a CLC block?

A CLC block is 100mm thick.

What is the mix ratio for CLC?

The mix ratio for CLC blocks is 1:3.

What is the price of CLC block in Pakistan?

The price of CLC blocks in Pakistan is PKR 70-100.

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