Paving Maintenance: How to Keep Your Cape Town Driveway Looking New

What does paving maintenance actually involve? For well-built block paving, the Concrete Manufacturers Association’s design manual lists three jobs: replacing jointing sand, treating weeds, and correcting surface levels where there were localised construction defects [2]. Most of the rest is cleaning, and the trick with cleaning is not emptying the joints while you do it.

Where we stand: paving is our trade, and we do the re-jointing and relaying of worn paving when home upkeep is no longer enough. We are not a cleaning company, so this is the routine for doing it yourself. We quote that manual [2], the CMA’s DIY paving guide [3] and the UK’s Interpave [4]. All are concrete paving industry bodies writing about their own product, so we say where the advice is ours.

How to clean paving, step by step

Sweep, deal with weeds and moss, test your cleaner on a hidden corner, scrub with soapy water and a stiff brush, rinse, then top up the joints once the paving is dry.

1. Sweep first. For general dirt and detritus, Interpave recommends regular brushing [4]. Clear leaves and grit out of the channels while you are there.
2. Pull weeds and treat moss before you wash. Weeds and moss are covered below; cleaning over them only moves the problem around.
3. Test a small patch. Try any cleaning method on a small, preferably inconspicuous area first [4].
4. Scrub. If the colour has become masked, scrub with soap and warm water [4]. For other stains, use a hard brush and a proprietary detergent, then wash off with clean water [3].
5. Rinse, and watch where the water goes. Cape Town’s Stormwater By-law bars putting anything other than stormwater into the stormwater system, or onto a surface where it could reasonably be expected to get there, without the City’s written consent [1]. Rinse all the soap off and channel the run-off to drainage points or containers for safe disposal [4]; in our view that means a garden bed or a container, not the street drain.
6. Let it dry, then re-sand. Brush dry jointing sand into any joints that have lost sand. Brush it in, don’t wash it in: washed-in sand forms a “bridge” that collapses later [3].

On clay pavers or natural stone, use the supplier’s cleaning advice: Interpave’s notes are written for precast concrete paving [4].

Pressure washing without emptying the joints

You can pressure-wash paving, but Interpave says care must be taken to avoid removing the jointing material, and that the paving should be inspected and the joints refilled as required afterwards [4].

If the joints empty every time you wash, or the paving rocks underfoot afterwards, stop washing and read the section on when maintenance is not enough, further down.

Which cleaner for which mark

Use a product made for that specific stain, follow its label, and test it on a hidden corner first. For the common marks, this is what Interpave and the CMA say [2][3][4].

Acid cleaners need respect. Wear protective clothing such as gloves and goggles, and when diluting, always add acid to water, never water to the cleaner [4]. The CMA’s DIY guide, on efflorescence, calls an acid wash “expert use only” [3], and in our view the same caution applies to any acid cleaner.

Moss that keeps coming back is a shade and drainage problem: treatments that leave a residue to discourage regrowth are of limited value if the paving stays damp and in shade [4].

Oil stains and sealing

Blot fresh oil straight away. For a set stain, the CMA suggests a product made for the job or, failing that, a strong detergent scrub and a wash-down [2]. On sealers for concrete pavers, the CMA’s guide lists surface sealants as not recommended [3]; the UK’s Interpave is warmer on them [4].

• Fresh oil: cover it with cat litter as soon as possible, so the oil is absorbed and the litter brushed off [3]. Blot a spill rather than wiping it, which drives the oil in and spreads it [4].
• Set stains: the CMA’s design manual points to “proprietary products which have been designed specifically for this purpose”, or, failing those, paving “scrubbed with a strong detergent and washed down with water” [2]. A detergent scrub might also leach out some pigment [4], so try it on a small area first.
• Sealers on concrete pavers: the CMA’s DIY guide lists surface sealants as “not recommended”, citing high initial cost, abrasion removing the sealer from the surface, and regular maintenance [3]. Interpave, the UK body, is warmer on sealing and calls it a potentially cost-effective way to improve appearance, but notes a sealer may affect colour and slip resistance, may need ongoing maintenance, and needs a dry, clean surface [4].
• If you do seal: we have found no re-seal interval we can stand behind. Check the sealer’s data sheet covers your surface, and follow it.

White bloom on new paving

A whitish bloom on new concrete pavers can be efflorescence. The CMA calls it mostly temporary and purely superficial, and says it usually disappears of its own accord [2].

• What it is: free lime in the cement, dissolved and carried to the surface by water, then left behind as the water evaporates [2].
• When it shows: generally early in the life of the pavers, particularly when water is present and it is cold [2].
• How long it lasts: the CMA’s DIY guide says it will disappear with time, “usually after two rainy seasons” [3].
• Does it matter? No: it “does not affect the durability or strength of the concrete paving units” [2].
• If it has to go now: the pavers can be given an acid wash [2], but the CMA’s DIY guide marks that “expert use only” [3]. In our view, waiting is the cheaper option.

Keep the joints full, with the right sand

Check the joints about three months after laying and again after the first heavy rain, and top up whenever they have dropped, including after a wash. The CMA’s design manual gives about three months [2]; its DIY guide says six months or the first heavy rain [3]. Use a finer plaster sand, not bedding sand.

The CMA says jointing sand “plays an important role in the performance” of block paving, and that a little clay or silt in it “helps seal the joints against water ingress” [2].

Correctly graded joint sand needs less maintenance [2]. A permeable paving driveway is a different build, with aggregate in its joints and its own routine.

Weeds: the CMA says most grow from seed, not from underneath

In large paved areas, the CMA says 90% of vegetation grows from wind-blown seeds germinating in the jointing sand [2]. Pull them while small and refill the gap.

• Check where the root starts. In most cases the stem ends and the roots begin just below the surface of the blocks, in the jointing sand [2].
• Growth from beneath, such as Kikuyu grass: a suitable herbicide can be mixed into the jointing sand or sprayed over the paving, used with care and with expert advice on which one [2].
• Skip plastic sheeting. The CMA does not recommend sheeting under the pavers to stop wind-blown seeds [2].

Our view: on a home driveway, pulling weeds while they are small and sweeping sand back into the gap is the simplest routine.

Keep water moving off the surface

“Most failures of pavements are due to ingress of water into the pavement layerwork,” says the CMA [2]. Keep channels, gullies and outlets clear so rain leaves the surface.

Water is the thread running through our guide to why paving fails early. Keeping the drains working is also on you: Cape Town’s Stormwater Management By-law requires the owner of a property with private stormwater systems to “at own cost, keep such stormwater systems functioning effectively” [1].

• Clear channels, gullies and grates of leaves and sand, especially through the wet months.
• Note where water stands after rain, and watch whether that spot grows.
• At a downpipe or stormwater outlet, the CMA’s two documents differ: the design manual suggests a little cement in the joint sand there, to help prevent wash-out [2], while its newer DIY guide says bentonite or a proprietary joint sealer, not cement [3]. In our view the newer guidance is the safer choice.

When cleaning and maintenance are not enough

A sunken patch or a ridge from tree roots points to a problem below the surface, and joints that keep washing out need a look at where the water is coming from. The CMA’s fix for settlement is to lift the area, address the problem, reinstate the level and re-lay the pavers [2].

Laying new paving near a mature tree? Say so at quote stage: as our notes on paving in Constantia put it, a root barrier or a layout that lifts and re-sets is cheaper designed in than retrofitted. Where roots have already lifted a section, ask an arborist about the tree before the paving goes back down.

Our guide to how a sunken section gets lifted and relaid walks through the repair. If the failure runs across the whole driveway, a new paved driveway is also a chance to rethink the layout and bond.

Just had paving laid? Run the checks on new paving before you pay, and see the full range of paving jobs we quote.

Common Questions

Paving sinking, lifting or losing its joints faster than you can refill them? We do free on-site assessments across Cape Town: we tell you what we think is going on underneath and follow with a written quote, with no obligation to use us for the work. See how we work out a price, or call 021 825 6396, weekdays 8am to 5pm.