Cover block price: what rebar spacers cost per slab
Published · Updated
The cover block price Kitovu gives on this page is for one plastic rebar chair with base, sold per piece from stock in Zanzibar. What a slab costs depends on how many you set: a Dutch supplier's guideline counts 1.5 large-base plastic spacers per square metre, against 3 large concrete blocks.
In stock in Zanzibar
See all 11 products
Plastic Rebar Chairs with Base (Rebar Spacers)
Plastic chairs that hold rebar at the right cover while concrete is poured.
Order on WhatsAppTZS 2,630perpiece
Polypropylene Fibre for Concrete and Mortar
12 mm polypropylene monofilament fibre against plastic shrinkage cracks, 0.9 kg per m³.
Order on WhatsAppTZS 15,100perkg
K11 Polymer Cement Waterproof Coating (Two-Component)
18 kg/barrelOrder on WhatsAppTZS 155,000perbucket
Cover block price at Kitovu: one plastic chair
The price shown above is for a single Plastic Rebar Chair with Base, sold by the piece from Kitovu’s stock in Zanzibar: a grey chair on a wide perforated foot with a clip on top for one bar, as Kitovu’s stock photo shows. It is not a price for concrete cover blocks, which hold the bars at cover depth in the same way.
Chair height, the bar diameters it accepts and the quantity in a pack are still to be confirmed. Height matters most, because it has to equal the concrete cover on your drawings, so ask for it before ordering.
Listed prices from other sellers
None so far. A search on 12 November 2026 turned up no seller in Tanzania publishing a price for cover blocks or plastic rebar spacers on a web page. The cover block price results that do appear come from India and Nepal, and a price from another country says nothing about what a block costs in Dar es Salaam or Zanzibar, so none is quoted here.
What changes the cost of spacers per slab
The price per piece is only half of the sum. The other half is the count, and that depends on the type of spacer. The Betonstaal guidelines for spacers, from a Dutch reinforcement supplier, give these quantities under slab mesh:
| Spacer type under a slab | Guideline quantity |
|---|---|
| Large concrete blocks | 3 per m² |
| Concrete setting rails | 2.5 per m² |
| Plastic spacers with a large base | 1.5 per m² |
Worked example (our calculation from that guideline): a slab of 6 × 5 m is 30 m². It takes 45 plastic chairs with a large base (30 × 1.5) or 90 large concrete blocks (30 × 3). Multiply the count by the price per piece of the type you choose. Your engineer’s specification overrides any guideline count.
Height is the second factor. The cover sets it, and the cover is a design decision: Eurocode 2 detailing rules as summarised by The Concrete Centre put it at no less than the bar size plus a deviation allowance, usually 10 mm. A chair lower than that cover leaves the steel short of it. Spacer types, layouts and the rules for setting cover are compared in the guide to rebar spacers and cover blocks.
How to get a quote
Send Kitovu a WhatsApp message with three things: the cover height on your drawings, the bar diameter that sits in the chair, and the slab area in square metres. Those three figures decide whether the chair in stock fits and how many the slab needs. Kitovu sells these chairs from stock in Zanzibar; prices for other materials are gathered on the building material prices page.