The 4 inch block is a partition unit. Used correctly it saves floor area, material and labour inside a building; used in the wrong place it is the most common cause of avoidable cracking in Zanzibar blockwork.
Internal partitions, non-load-bearing divisions, bathroom and service walls, and fit-out works where the wall divides space rather than carries it. Because it is thinner, each square metre of wall costs less in material and takes less time to lay, and the building gains usable floor area.
What it should not do is carry structural load, form an exposed boundary wall, or take the brunt of wind-driven rain on an external face — those are 6 inch or 8 inch jobs.
Most buildings need both sizes, and it is worth ordering them together. A combined quantity lets us plan production and schedule the deliveries so partitions arrive at the fit-out stage rather than sitting on site absorbing damage during the structural works.
Projects rarely order one material alone. These are the categories most often quoted alongside it.
Hydraulically moulded 4, 6 and 8 inch cement blocks made in Zanzibar, cured under controlled conditions and delivered across Unguja.
View concrete blocksThe standard walling block in Zanzibar — for load-bearing walls, the external envelope and boundary walls.
View 6" blocksHeavy-section block for tall perimeter walls, retaining situations and structural walling specified by the engineer.
View 8" blocksBagged cement (Dangote CEM II 42.5N, 50 kg) supplied in Zanzibar and staged against pour schedules and site storage.
View cementShort, practical guides written for Zanzibar sites — selection, quantities and what to send with an enquiry.
Which block size belongs where, what each one costs you in floor area and labour, and where projects most often get the choice wrong.
Read the guideEstimate from wall area rather than guesswork: the method, the deductions, the waste allowance and what to send us for an accurate quote.
Read the guideStone Town, Nungwi, Kiwengwa, Paje, Fumba, Wider Unguja and the wider island. Delivery feasibility and cost depend on quantity, access, route and schedule — confirmed in writing per order.
We do not recommend it. External and load-bearing walls should use 6 inch or 8 inch units as specified by the design team.
Per square metre of wall they usually are, because there is less material per unit and laying is quicker — but only where a partition unit is the correct choice structurally.
Yes. Combined orders are scheduled together so each size arrives at the stage of works that needs it.
Upload your BOQ or send us your full material requirement and Build Hub will prepare a consolidated quotation.
Send your quantities, site location and required dates — or attach a BOQ or material schedule — and our team will come back with a written quotation and a delivery plan.
