I know the article in your Jan/Feb 2025 issue’s main emphasis is "you pay for what you get" regarding the products durability but contractors should
I know the article in your Jan/Feb 2025 issue’s main emphasis is “you pay for what you get” regarding the products durability but contractors should be aware of the following which the article does not cover and is of more importance in the long run.
A normal South African wheelbarrow as made by Lasher or the like is of 65 litre capacity and all mixing ratios of cement: building/plaster sand uses this wheelbarrow as a standard of measure.
Note that a standard local builders wheelbarrow holds 2 bags of cement meaning a specified mixing ratio of 1:6 is two pockets of cement: 6 wheelbarrows of sand. We are now seeing more and more wheelbarrows coming in from Asia and they are bigger and less durable than a Lasher builders wheelbarrow but they are also cheaper. As such if we still use the 2 pockets of cement, we are putting in excessive sand (depending on the size of the w/barrow used if it is not the standard South African sized wheelbarrow).
The results is a weak friable mortar or plaster. This needs to be addressed by institutions such as the professional industry bodies.
Considering the amount of houses we are building and the financial burden of the people buying these houses this weaker, poorer quality of masonry construction should be addressed. The long-term maintenance of such houses regarding cracking, damp proofing, painting, moisture ingress etc is potentially a major burden especially if the house is bonded.
Yours sincerely
Calvin Billett
Quantum ready mixed concrete
