Concrete block paving is the most common driveway surface in South Africa: it carries cars well, drains better than a solid slab, and can be lifted and relaid when a pipe needs fixing. A paved driveway is only as good as what is underneath it, though. This guide follows the Concrete Manufacturers Association’s (CMA) step-by-step guide to paving, from the order to the final sweep.
Choosing pavers
Pavers must be strong enough for the traffic they will carry: foot traffic, domestic cars or heavy vehicles. The CMA notes that interlocking shapes perform better under heavy traffic, and recommends SABS-approved pavers made to SANS 1058 and kerbs made to SANS 927. Good pavers have tight tolerances (±2 mm on length and width, ±3 mm on height), a small chamfer on the top edges to help water drain, and lugs or spacers of no more than 3 mm that keep the joints even.
How much to order
- Pavers are sold per square metre. Interlocking 200 × 100 × 60 mm pavers work out at about 50 per m² (Stone Lifestyle sells them 500 to a pallet). Measure length × width for rectangles and π × radius² for circles, and add 10% for cutting and waste, as the CMA advises.
- Kerbs = total length of edging ÷ length of one kerb unit, plus 10%.
- Bedding sand: good-quality, well-graded washed river sand at about 6 to 7% moisture. Order 2.5 m³ per 100 m² of paving, enough for a 25 mm layer.
- Jointing sand: fine plaster sand, completely dry, about 10% of the bedding sand.
- Cement only for setting kerbs and for stabilising a poor base: the CMA suggests about 1.5 bags (75 kg) per m² when stabilising.
The paver calculator counts pavers, base, bedding sand, jointing sand and edging; the excavation calculator sizes the skips for the soil you dig out.
Preparing the site
Check for underground services before you dig: water pipes, electrical cables, sewers and gate-motor cables often run under driveways. Plan the falls: paving should slope away from buildings, with a minimum fall of 1 in 50 in one direction so water runs off. Where water stands for long after rain, improve the drainage before paving.
Excavate and shape the base so that, once compacted, it sits at the paver thickness plus about 20 mm below the finished level. The CMA warns that the paving will follow every bump and dip in the base, so compact it well, check for soft spots and fix them. A poor subgrade, or one that will carry heavy vehicles, can be stabilised with cement. The depth of base course a driveway needs depends on the ground and the traffic; ask your supplier or an engineer for heavy-duty work.
Edges first
Paving must be held at the edges or it spreads and loses its interlock. Lay kerbs on a 70 to 100 mm bed of concrete or dagha, fill the gaps between units, and let them set before you compact the pavers against them. Where paving meets a wall, slope it away from the wall.
Bedding sand, laying and jointing
The CMA asks for steps five to seven to be finished on the same day:
- Bedding sand. Lay rails about 3 m apart and screed the sand to a loose layer of about 25 mm, which compacts to about 20 mm. Don’t walk on the screeded sand. Don’t lay the sand on plastic sheeting: it spoils the interlock, traps water and doesn’t stop weeds.
- Lay and compact. Lay pavers in the chosen pattern, working from the lowest point up the slope, cut the edge pieces, and compact with a plate compactor.
- Jointing sand. Sweep dry, fine sand into the joints and compact again until the joints are full.
Looking after it
The CMA’s maintenance advice: resand the joints and vibrate the paving again after six months or after the first heavy rain. Where paving settles, lift the pavers carefully, add or adjust the sand and relay them. A whitish bloom on new pavers (efflorescence) is natural and usually disappears after about two rainy seasons. Soak up oil stains quickly with cat litter, and scrub other stains with a hard brush and a proprietary detergent. The CMA doesn’t recommend surface sealers, which cost a lot at first, wear off and need regular upkeep. When a pipe under the paving needs repair, lift the pavers, fix the pipe, rebuild and compact the base, and relay them.
This guide is general information for estimating. It is not engineering, legal or tax advice. Check SANS 10400 (the National Building Regulations) and your local municipality’s building control officer for your project.