Kal Kalai

Contrasting Brick Masonry & CSEB Construction

I had been exposed to brick masonry way too little for an engineer than an average person. My first couple of internships outside of college were related to Steel Structures. I went for a few site visits in Trichy, which were my first-hand experiences with brick masonry.

Unfortunately, those were all in stages other than wall construction, which meant I was least exposed to brick masonry.

Brick wall to hold the ramp for staircase

This project took me farther away from brick masonry, and when the building was near completion and we were getting ready to add a staircase and other finishing touches, we decided to use normal bricks (to save money) as they would be covered with tiles or plastered.

Filling the gap with soil and demolition waste before concreting. 12mm Bars were extended from the verandah space while concreting, those are now tied along with the rebars for the ramp

The shift made evident the difference between CSEB (Compressed Stabilized Earth Blocks) and regular brick construction, and I think it's totally noteworthy to mention here:

• An average human can carry a maximum of 2-3 CSEB blocks due to their weight and size, whereas people can easily carry up to 11 regular bricks.

• Regular bricks are small and they hardly have edges, that is they are not perfectly in cuboid shape. They can also be easily broken by hitting with a heavy object whereas CSEB needs to be cut using a Wall Cutter blade and a machine, creating a lot of dust in the process. This also means for any small coverup CSEB makes it hard to cover up, unlike regular bricks.

• Regular bricks are smaller in size and require about two layers for the outer wall (9") and one layer (4.5") for the partition walls. It's sufficient to build with just one layer of CSEB blocks (in my case, 6" thick walls).

• Regular bricks don't take up as much load as CSEB blocks. It's best to conduct a compressive strength test if regular bricks are to be used for load-bearing structures.

• The price of a regular brick is about 1/5th to 1/4th that of CSEB blocks.

• Exposed brick walls give beautiful aesthetics, but that would require good quality, preferably wire-cut bricks completed with pointing to match the regular CSEB block finish.

• It's easier to find masons and labourers to work with regular bricks, which also means the speed of work is faster with regular bricks. It also allows for error correction at the time of plastering, unlike CSEB blocks.

• It is not economical to use CSEB wherever there would be plastering or covering up with tiles involved. Also, because it might be harder to plaster on CSEB due to the smooth finish of the blocks (blocks are made using moulds and tend to have fewer irregularities).

• From what I have seen, the amount of mortar required to hold together the bricks is comparatively higher compared to that of the mortar poured into the CSEB interlocking blocks. Adding to this would be the cement and sand used for plastering. CSEB, for sure, saves cement, sand, and time in terms of plastering.

Brick stairs built on the concrete stair ramp - Using Straight edge to check for flatness

Now, with the limited exposure to regular brick masonry, here are a few things that I thought I'd put down here. These might look too simple for anyone who has been exposed to construction work and has been on-site when their house was constructed. But for an engineer like me, straight out of college, who grew up in a neighbourhood where no one built a new house - all this might be useful.

Plus, learning a local language is mandatory when we are to deal with people who don't speak in technical terms like we do. These instruments and techniques are not only used for brick masonry but also by those fixing tiles, plumbers, carpenters, etc.

• Workers generally talk in precisions up to 1/4" - Kaal-inch (1/4"), Arai-Inch (1/2"), Mukkal-Inch (3/4"), and so on.

• Important checks when building a wall or any basic structure:

  • Moola Mattam - Right Angle: To verify the corners of the building.

  • Thooku Gundu - Plumb Bob: To check if the entire height of the wall is standing straight or if it is inclined. Necessary to make sure the centre of gravity of the wall rests in the centre.

  • Level Tube - Water Level: Very frequently used. To check if the building is built on a levelled surface. Checks if multiple points are on the same level. Helpful to provide slopes and drains in bathrooms and open spaces.

  • Rasa Mattam - Spirit Level: Analogous to a level tube but used to check for a smaller area.

  • Matta Kambu: Straight Edge. Used for plastering and to check the alignment of bricks

I can't say how much of this jargon has already become a part of me and how much I am losing my English terms already. One thing with being on-site doing small projects (projects that don't require much computer modelling and stuff) is that I have been losing touch with technicalities. Terms like Fck, Fcb, Tensile forces, Compressive strength all seem distant, and I wonder if I will be able to recall how to design beams and columns in Staad anymore.

That's a teeny bit scary, putting my entire 4-year course in question, but I am also happy that I am able to do something I like. I had never been sure if I liked civil engineering, but now I can see that I like seeing buildings rise. I like it when people ask me, "Was that you who wanted a circular window there?", " How did you hear about these bricks?", "How have you planned the roof of this building?" I like to see how all that I saw as a 3D model in SketchUp is coming to life and how I am learning to solve more practical problems that arise during execution instead of technical problems like an engineer I studied to be.

I'm not really sure what my future has in store for me, but I think for now, I'll sit down on the Thinnai I have built and give myself some time to breathe because it feels like just the place I want to be in.

At the end of the day, I am happy to be an artist who engineers.

There's art in engineering, Lla?