Clay bricks vs concrete blocks

One concrete block covers the space of almost four bricks. Photos/Tony Mushoborozi.

What you need to know:

  • Both concrete blocks and traditional clay bricks are tried and tested as dependable building materials. They are both so trusted that it almost feels like it does not matter which one you chose. But it does matter actually.

You have worked your fingers to the bone for years, planning, executing impossible tasks, saving, closing deals, and thankfully, you are finally able to build your own house. Now you are starting to think about the specifics of the job ahead. When you get to the most basic building material, namely, the bricks, you are not sure whether to use clay bricks or concrete ones. 

Both concrete blocks and traditional clay bricks are tried and tested as dependable building materials. They are both durable, fire-resistant and insect-proof. They have both been used in the construction of buildings that have lasted generations. They are both so trusted that it almost feels like it does not matter which one you chose. But it does matter actually.

Differences and similarities 
Concrete blocks are made of stone dust and cement, making them very strong as a construction material.  Clay bricks on the other hand are made of that stiff, sticky, fine-grained earth that can be molded when wet. Clay bricks are dried and burnished for the purpose of hardening them and inoculating them from the damages of the elements.

While clay bricks have always been the favourite in Uganda’s commercial construction world, if you have been paying attention lately, you may have realised that concrete blocks are becoming more popular. In the past, concrete blocks were almost always exclusively preferred in large-scale construction projects, while clay bricks were preferred by home builders.

 However, concrete blocks are becoming mainstream, lately, and they are becoming more common in regular home construction projects and many other applications like perimeter fences, and so on. 

Today, one is likely to think about the two options as they get closer to starting a construction project. Bricks seem to have lost their position as the default choice. There are pros and cons of using either material and therefore, good reasons for choosing one over the other.

Pros of concrete blocks vs clay bricks
According to industry expert Cissy Namaganda, who runs a Cinam Investments Limited, a construction business, concrete blocks are her choice material in most construction projects because of several reasons. 

“As someone who always endeavors to help my clients save money on construction projects, I always advise my clients to choose concrete blocks because it just makes business sense. Concrete blocks are much more uniformly shaped than clay bricks and that goes a long way to save money that would have been spent on cement and sand.
“The job moves a lot faster because concrete blocks are larger than clay bricks. One concrete block covers the space of almost four bricks. That saves on labour and time, and once the walling is finished, there is so much less time and resources needed to plaster the walls because there almost no inconsistences to correct,” Namaganda says.

This is a win-win situation. The clients saves money of the project and the contractor moves onto another project in the shortest time possible.

Concrete blocks are larger than clay bricks, which makes construction faster.

Quality assurances
Apollo Buregyeya is an expert in the construction business and runs Eco Concrete, a company that deals in the manufacture of construction materials, currently developing a green cement for the Ugandan market. 
Buregyeya says that the advantages of using concrete blocks over clay bricks come in three layers, the first being a much higher value finishing because the dimensions are more uniform.

“If you are in the business of building houses for sale, you must choose concrete blocks. The house will look stronger and more professionally done than the one built with bricks, and the house will be a lot easier to sale than the one built with clay bricks because concrete blocks increase the value of the house in numerous ways,” he says. 
According to Buregyeya, there is no technical advantage of using clay bricks over using concrete blocks. 

“Technically, concrete blocks have an advantage over clay bricks.  For example, clay bricks are more likely to be of poor quality than concrete blocks. The problem of dump walls is strictly characteristic of brick walls because of quality issues. Bricks in Uganda are very problematic because they a very high water absorption rate. Why? Because there is no quality control. There is no standard amount of water to add in clay before molding. Brick layers go to swamps and dig soil without any standards of how much roots and leaves and dead matter to eliminate from the clay before laying the bricks. This makes most of the bricks on the market very permeable,” he says. 

He adds, “Do this experiment on your own. Weigh one concrete block and one clay brick. Immerse them in water and let them stay overnight. Remove them and let them dry for a week and weigh them again. The concrete block will go back to the original weight but the clay brick will not. 

“This means that during the rainy season, the walls of a house built with bricks will absorb huge amounts of water and expand. Once the dry season comes, the water in the bricks will start evaporating and the bricks shrinking. This is why most walls peel. Brick walls are susceptible to plaster flaking which cannot happen with concrete blocks,” he says.

Yes, the concrete blocks absorb water too, but the water gets to evaporate out of them immediately.

Cons of concrete blocks vs clay bricks
One of the greatest problems with using concrete blocks, according to industry experts is that if they are not sourced from the right manufacturer, they will tend to break a lot more easily than clay bricks. Clay bricks tend to be a lot tougher in general plus their small size helps them to be less susceptible to breaking. 
The other disadvantage of using concrete blocks is that on small projects, it tends to be more expensive than if one used clay bricks, according to Buregyeya. 

Concrete blocks are not available everywhere and transporting them is a lot trickier because they break more easily in transit according to Namaganda. Bricks on the other hand are available in every corner of the country which makes transporting them less risky because their ready availability means the distances to construction sites are short. 

Namaganda advises that one must do due diligence and get the right supplier who also offers warranty on his product. This will help eliminate bad actors that sell poor products.
“If you get blocks with poor mixes, this may turn out to be an unmitigated disaster,” she says.

Clay bricks help save money on transportation as they can be made on site.

Buregyeya says many Ugandans are mistaken into thinking that they save a lot of money by using bricks in construction. 

“We forget that walling only takes less than 5 percent of the total cost of a house. A standard three-bedroom house will easily cost about Shs180m. Of that, only Shs8m will be spent on bricks. But you find people putting a lot of focus on saving money on bricks by doing things like making their own bricks at home and so on,” he says.

He adds that a three-bedroom house will typically take about 20,000 clay bricks at an average of Shs400 each. The same house will need about 6000 concrete blocks each at Shs2,800. 

This means that the one who buys bricks will pay Shs8m while concrete blocks will cost Shs16.8m. That, on the face of it looks like a big saving but experts say it is deceptive.

Namaganda adds that while the price of concrete blocks is high on face value, it is actually cheaper in the end.  The money saved by buying bricks will be swallowed by higher costs in cement and sand, labour and duration of constructing a brick house. 
Buregyeya adds that bricks are also bad for the environment. Swamps are pillaged for clay, ruining nature’s plumbing system, and there is eventual deforestation because the bricks must be burnt. 

Pros of bricks over cement blocks
The only advantage of bricks over concrete blocks is that it employs more people to lay them, burns them, trade in them and transport them according to Buregyeya.
“The other advantage is that clay bricks are accessible in places where concrete blocks are not, and considering that most construction in Uganda is mainly incremental and only progresses at the rate the builder can raise money, it supports low income earners to progressively build their homes,” he says.

Concrete blocks have a much higher water resistance capability than bricks, and their compressive strength is higher. While clay bricks are known to outlast concrete blocks, the lifespan of concrete blocks give you efficient results for up to 100 years.  On top of that, solid concrete blocks offer outstanding fire resistance and they are far better than bricks at sound insulation. 

All experts seem to agree that technically, there are no advantages of using bricks over blocks. From aesthetics qualities to the sturdiness of the house, concrete blocks seem to win. And this is slowly dawning on Ugandans, making concrete clocks more and more popular today.