Chapter Two
Bricks and Masonry work
The most common tale in the Tanzanian society is contracting a local fundi for masonry work. Masonry work, as defined by constructor.org, is a form of construction that is done through systematically laying bricks in mortar (a mixture of cement, water and sand) to form a solid mass that can sustain structural load. They also mention that it is the most durable form of construction. Well at least for Tanzania it has been the most dominant form of construction, but durable? I still wonder too. Please refer to my last article on durability properties of construction work.
It is customary for every local fundi to own their own tape measure, trowel level, a spirit level, a plumb line, and occasionally a mason ruler/bevel and a hammer. One of my most fascinating tool should be the water level, it ideally works similarly to the spirit level (If you come across any, please send me a comment or a picture attached) but uses the principle that water always finds it’s own level (a stepping concept for another article to explain the Jangwani drainage crisis) to illustrate a vertical level. That is when the two ends of the tube are held up, the water surfaces will always rest on the same vertical plane.
Masonry work in Tanzania has essentially been the work of a local fundi and trust me when I say that in every corner of this country there are a few available for you.
Now, one of the most crucial aspects I would like to point out in this article is the design of mortar. I mentioned earlier on about this mixture of cement, water and sand because mortar has such a large impact on the performance and longevity of masonry structures, extra attention should be exercised when mixing and placing it. Depending on the standards of use in the country most local fundi’s translate this design mix into their own understanding. In Tanzania, the mix design follows a volume based ratio rather than weight based ratio.
I have come across a number of local fundi’s with the same answer, “ndoo moja ya cement kwa ndoo tano za mchanga” meaning, one bucket of cement to five buckets of sand. Hence a 1:5 volume ratio of 10 liter buckets which represents 0.01 cubic meters.
Caution: This is an example and not a standard requirement, once again this requirement depends on standard of use, local material consideration and sections of the building. Masonry work for more load sustaining sections such as foundations take in more cement and less sand than less load sustaining sections such as wall partitions.
If you are going to take anything from this article then please go away with the importance of making sure the mortar ratio is proportioned adequately and sufficiently. Most deterioration originating from masonry work is found to have started from poor workmanship and insufficient mix design. As the popular saying goes, Garbage in, garbage out.
A personal favorite type of masonry work for me is brick construction. I mean, if you ask me in my sleep, “Kemmie, what is the ultimate construction material for you”, I will randomly choose bricks. Why? Hear me out here, Brick provide structural strength, longevity, aesthetics, ease to work with, insulation properties and durability in one material.
And yes — The fact that they use about 800 -1100 degrees centigrade during the production process is a bummer and a blessing in disguise. In addition, this process can be locally adjusted to suit it’s requirements as well as modernized to cut down any unwanted gas emissions and make the process greener and sustainable. National standards and manuals have been developed in countries such as India and Switzerland for such purposes. Other bumming factors include, sourcing/soil geology, investment in adequate equipment's as well as transportation costs.
The main reason as to why I put the picture below, (for those wanting to know where in Dar this is; this is the @ncbabanktz building right between it and the FNB building), it is because of the brilliant use of alternative materials in this building. The main structural elements are heavily invested with concrete while the walls and other opening are made of bricks and steel.
In Dar es salaam, which is the most urban city in Tanzania, the most common construction material is concrete and block work. And with concrete reasons as well, because when you factor in availability of resources and local fundi’s that are conversant with the technology, very few things top that. Strength and durability requirements play a large role in the selection of these materials.
The opposite is found in most north- and southern regions of Tanzania, where there is ample soil geology, lower costs of sourcing and production as well as well local fundi’s to deal with the material. It should be noted that the difference in temperatures between central Tanzania and North or Southern Tanzania is significant. Whereas; in the northern and Southern they experience colder temperatures of less than 5 degrees centigrade during winter, in the central Tanzania it’s mostly a constant hot temperature of not less than 22 degrees centigrade during winter seasons.
Earlier on in my explanation of why I prefer bricks, I mention “insulation properties” which further ties into my explanation here. Bricks have high insulation properties as compared to other construction materials such as blocks and concrete. During a hot season, bricks can be used to isolate the heat and retain an artificial induced colder environment such as the use of air conditioners inside buildings. Whereas; you can use a chimney to induce heat inside the house and keep the cold outside.
Currently, one of the biggest hurdles of adopting bricks in Dar es salaam, should be the manufacturing process and maybe soil source. I am confident that both can be researched, invested upon and make financial sense for the long-term durability of buildings. If you know anywhere that manufactures or sells good affordable bricks, and has done a couple projects as well using bricks in Dar es salaam, please drop a comment, I would love to get myself acquainted with them.
If you work in the Tanzanian construction material field and want to be part of this journey with me? Yes — Please, Welcome. Reach out to me through the comment section as well as my official Instagram page (@thefunditales)
That’s all from me, and my tales of the fundi through a sustainable eye.
