The 8 inch block is the heavy section: used where the wall has to resist more than it divides — retaining situations, tall perimeter walls and structural walling specified by the engineer.
An 8 inch unit costs more per block and slows the laying rate, so it should be specified deliberately. It earns that cost where the wall retains ground, stands tall and exposed, carries heavier structural load, or needs a wider core for vertical reinforcement and grout.
On coastal Zanzibar sites, exposure is a real factor — a tall boundary wall facing prevailing weather behaves very differently from a sheltered internal wall of the same height.
Where 8 inch blockwork is being reinforced, the bar schedule and the block order need to be agreed together: bar diameter, spacing and lap positions all affect the coursing and the practical build sequence. We supply reinforcement steel alongside blocks, so both can be quoted and scheduled on one order.
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" blocksY bar and reinforcing steel by diameter, supplied with binding wire and mesh for slabs, columns, beams and foundations.
View rebarBagged 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.
Retaining walls must be designed by an engineer. An 8 inch unit is often the practical minimum for reinforced blockwork retaining, but the design — not the block size — governs.
Yes, where the design calls for it. Agree the bar schedule before ordering so coursing and lap positions work with the units.
For most internal and standard external walls, 6 inch is the normal choice. 8 inch is usually reserved for tall boundary walls, retaining situations and specified structural walls.
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.
