Commercial Paving Specifications: What Cape Town Body Corporates Need to Know

A townhouse-complex road, a visitor car park or a refuse-truck route is not a big driveway. It carries heavier vehicles more often, so the paver, base, edges and handover checks need writing down before anyone digs.

Where we stand: the commercial paving we lay is priced from a written quote, not a rate card. Most of the figures below come from the Concrete Manufacturers Association (CMA) Concrete Block Paving manuals — the precast concrete industry’s own guidance, not an independent regulator.

Why commercial paving is specified differently

More vehicles, heavier vehicles and more turning, so the pavement is designed for the traffic rather than copied from a driveway.

• The design starts from traffic. Catalogue designs classify a road by its traffic and climate, but Book 2 says such methods are “in general, only applicable to roads and not suitable for the design of industrial pavements” [1]. A loading area or refuse-truck turning circle needs an engineer’s design.
• Edges carry load. A footpath may need only a small precast kerb, but “in a high-traffic industrial area heavy duty concrete kerbs or a reinforced concrete ground beam may be necessary” [1].
• Water is the usual culprit. “Most failures of pavements are due to ingress of water into the pavement layerwork”; CMA says a minimum 2% fall is generally required, with paving laid 5–10mm proud of stormwater structures [1].

The right paver for the loading

An 80mm interlocking block in herringbone. Blocks thicker than 80mm add little, and a higher strength class earns its cost only under heavy wheel loads or severe conditions.

Book 3’s clause, reproduced from SANS 1200 MJ, makes the lower of its two classes the default except for paving under wheel loads over 30 kN or where the project specification schedules the higher class, and its commentary adds exceptional loads and severe service or environmental conditions [2]. Those are the historical compressive classes, 25 and 35 MPa, from SANS 1058-1985. Today’s SANS 1058 grades blocks by tensile splitting strength instead — Class 30/2.0 at a 2.0 MPa average and Class 40/2.6 at 2.6 MPa [3] — so ask your engineer which current class to name.

Standards and testing

Name SANS 1058 for the blocks and a specification for the laying, then write the handover checks, and who pays for them, into the contract.

• SANS 1058 covers the block as a product: tensile splitting strength, abrasion (15g average, 20g individual) and water absorption (6.50% average, 8% individual) [3]. It is separate from the specification for laying [2], so a supplier’s certificate says nothing about whether the laying was any good.
• SANS 1200 MJ is, in Book 3’s words, “the standardised specification for civil engineering construction of segmented paving” [2]. SABS technical committee TC 1098 agreed to withdraw the whole SANS 1200 series in April 2016, so it no longer has national standard status, though it can still be bought from SABS [4].
• SANS 1200 DM and ME cover the subgrade and subbase, which MJ refers out to [2]; they went in the same 2016 withdrawal [4]. Book 3’s commentary puts “the strength and the line and level of the layerworks” on the main contractor [2], so say in the contract who builds and tests the base.

Book 3’s finished-surface limits (the first three below) are for Degree of Accuracy I, the only class it gives numbers for, and are measured “3 months after opening to traffic”; its commentary lets them be relaxed for economy, but never the tolerances on the blocks themselves [2]. The rest are construction and testing requirements from the same book.

• Adjacent pavers: a difference in level “not to exceed” 3mm [2].
• Under a 3m straight edge: +3mm/−0mm at kerbs, channels, gullies, manholes and other edge restraints, and +10mm/−15mm elsewhere. Book 3’s commentary calls the kerb figure “very difficult to achieve and … not critical provided that adequate falls are met” [2].
• Pattern lines: a joint line strays no more than 10mm from any 3m straight line, and no more than 20mm from any 20m line [2].
• Joints: “between 2 mm and 6 mm”, with a rule of thumb that they “average 3 mm over 20 blocks” [2].
• Base: tested under SANS 1200 DM and ME, with any depressions filled with subbase material “compacted to 98% of modified AASHTO maximum density” — never bedding sand [2].
• Flood test: the engineer may order the surface flooded; the contractor fixes any ponding “at his own expense”, and if none occurs the employer pays for the test [2].
• Heavy traffic: paving regularly carrying wheel loads over 30 kN gets at least five passes of a heavy pneumatic-tyred roller after joint filling [2].

What drives the cost on a commercial job

The engineer’s design for your traffic sets the price, so we don’t publish a rate. Make every bidder price the same separate lines.

We don’t publish a rate for this any more than for any of our other paving work. Ask for these as separate priced lines:

• Demolition and disposal of the existing surface.
• Subbase to the engineer’s design, with the compaction standard named.
• Ground improvement, if the test results call for it.
• Kerbs and edge restraints to a drawing detail.
• Drainage tie-ins to the existing stormwater system.
• Traffic management and phasing on an occupied site.
• Handover testing, with the results in writing.

Whether the job is a gated complex in Century City or an office park elsewhere, an all-in rate can’t be compared line by line with an itemised quote — the same logic as what moves a residential paving price.

The procurement process — what to ask in your tender

Ask every bidder for the same documents, so the prices you compare cover the same work.

Book 3 also lets the first section laid, at least 20m by about 6m, be a trial section the engineer approves before full laying, though its commentary says this need not be mandatory for experienced contractors [2]. In our view, a bidder who can’t produce the checklist isn’t ready for an occupied complex.

Defects-liability period — write it into the contract

Ask for a written workmanship warranty and a defects-liability period on top of it. We have found no South African standard that sets the length of either, so both are negotiated.

• Name the period and when it starts, for example from the signed handover.
• Say what the contractor must come back and fix during it, and how quickly they must respond.
• Make the period run past the three-month mark and walk the site again before it ends, since Book 3 measures finished-surface tolerances three months after opening to traffic [2].

If the base, drainage or edges are not properly designed and built, Book 2 warns “excessive maintenance may be required during the life of the pavement”, and where defects are local, “repairs are not usually difficult, time consuming or costly” [1] — typically lifting and relaying a sunken section.

Common Questions

Planning work on a complex, office park or retail site? We do a free site survey and follow it with a written quote, and phasing or after-hours work is something we can programme where the site has to stay open. See how we put a quote together, or call 021 825 6396, weekdays 8am to 5pm.