Interlocking bricks – as the name suggests locks itself with other bricks and it is these interlocks which give strength to the wall. No cement mixture is needed for the bonding.
This is a concept which many people Kerala is not well aware of. People often tend to reject anything which is new. Same was the case with Interlocking bricks, as was evident by the response of people whom I approached to get expert opinion on the usage of these bricks.
It was my architect who introduced this concept to me. After visiting two or three houses built by the architect using these bricks, I decided that I was going to use this for construction.
The major difference with the normal bricks used for construction and the interlocking bricks are
- Interlocking bricks are not baked, it is just mud in high density pressed using a pressing machine and allowed to solidify by drying naturally. Some chemicals are added for increasing the bondstrength. Normal bricks are baked ones
- Size of interlocking brick is more. Approximately it is 2.5 times more in volume than the baked bricks.
- Weight of Interlocking bricks is more than equivalent volume of baked bricks.
Method of Construction using interlocking bricks
1. Normal basement is to be laid down first. Since the interlocking bricks have more weight than conventional bricks, a more stronger basement is needed.
2. Once basement is laid, one layer of normal baked bricks is placed over the basement. Width of this layer shall match with the thickness of the wall which is going to be built using interlocking bricks.
3. The Interlocking bricks are neatly arranged over this layer. (Experienced labourers are a must, since any irregularities in their placement cannot be corrected at a later stage.
4. While concreting the roof, ensure that the edges of the roof projects out a little more than the wall. This is to ensure that rain water do not flow through the walls.
5. Once the construction is complete the corners of the wall are completely plastered using the cement. This helps to have adequate pressure from the sides of the building for the bricks bonded together. The pressure from the top is from the concrete above. So it is as if the interlocking is placed with adequate pressure from all the four boundaries.
Before plastering the edges
after plastering the edges
A close up view of the plastered edges
6. The external wall can be left as such without painting. But the gaps have to be filled with like colored cement.
If painting need to be done, it can be done directly over this wall. (I chose not to paint)
7. If internal wall need to be plastered, it is better to make the surface rough before plastering, since the surface of this brick is relatively smooth.
Advantages of Interlocking bricks
1. Cost saving in terms of cement, sand and water.
2. Design is more blended with nature as arificial bonding mechanism is completely done away with
3. The walls have more strength than the normal walls. (just hit the wall and listen to the sound of walls made by interlocking bricks as well as by normal bricks)
4. These bricks does not heat up as fast as normal bricks, hence the room will remain cooler.
5. Since no painting is required another cost saving
Disadvantage of Interlocking Bricks
1. The space between the interlocks of these bricks is enough for insects and ants to set up there homes. (To avoid this point the gaps using cement mixed with redoxide and do periodic mainteance once in 6 years)
2. If rain water flows through these bricks, the color of the brick changes very fast.
3. It is difficult to ensure availability of the same coloured bricks for the entire construction. If painting is not planned, all the bricks should be having the same color. For this all these bricks have to made from the soil of the same place.
4. Not suitable for buildings having more than 2 floors, if it is not supported by pillars. Pillars are not needed for double storeyed buildings.