The complete block paving construction process, step by step

Step 1 – Preparation and planning

Every successful paving job starts with thorough preparation:

• site survey and measurement, locating buried utilities,
• assessing bearing capacity and drainage conditions,
• setting out the formation level,
• determining the falls,
• setting out kerbs, drainage channels and gullies,
• planning the removal of weak, organic, fill or waterlogged soil.

Keep in mind: depending on the scope of the works, a minor works licence (licencia de obra menor) or a prior notification at the town hall may be required; any work on public land needs municipal authorisation.

Step 2 – Earthworks and formation level

1. Removal of topsoil, silt and organic matter (typically 20–40 cm).
2. Replacement of weak soil with granular material.
3. Shaping the formation level to the designed falls.
4. Compacting the formation with a plate compactor or roller.
5. Replacing soft spots with granular material.
6. Where necessary, a geotextile to separate the subgrade from the sub-base.
7. Under heavy loads a geogrid can be used to improve bearing capacity.

The compaction requirement for the formation (Ev2 modulus, plate load test) is set in line with the Spanish PG-3 specifications and technical recommendations for pavements; check the current values applicable to your project.

Step 3 – Building the sub-base

Typical materials:

• 0/32, 0/45, 0/56 crushed stone (aggregates to UNE-EN 13242),
• stabilised granular base,
• sandy gravel only for light duty, with a suitable grading,
• cement-treated base (soil-cement / lean concrete) for heavier loads,
• open-graded crushed stone for permeable pavements.

Placing:

• spreading in layers (max. 15–25 cm compacted layer thickness),
• keeping to the optimum moisture content,
• compaction with a vibrating roller or heavy plate compactor,
• level checking with a laser or string line.

Step 4 – Edge restraints (a key element!)

The functions of the kerb:

• lateral restraint – the blocks only hold their position against a stable kerb,
• transferring loads to the ground,
• preventing the pavement from "spreading" apart.

Kerb types:

• garden edging (private properties),
• road kerb (trafficked areas),
• dropped kerb (vehicle crossings, accessibility),
• kerb with drainage channel (an inclined unit beside the pavement that collects and carries rainwater – standard practice in Spanish urbanisation works),
• concrete haunching (concrete collar).

Execution: kerbs must be set on a concrete bed with concrete haunching behind. Without edge restraint, the pavement creeps apart and the edges sink.

Step 5 – Bedding layer

The bedding layer is the levelling, load-spreading layer directly under the blocks:

• Material: washed grit, e.g. 2/5 or 4/8 mm fraction.
• Thickness: 3–5 cm after compaction – no more!
• Important: the bedding must not be pre-compacted separately; it takes its final set together with the blocks during final vibration.

Typical mistakes:

• Using sand under heavier loads: it washes out and silts up.
• Too thick a bedding (6–10 cm): rutting, undulation, settlement.
• Pre-compaction: the bedding gets squeezed apart during laying.

Step 6 – Laying the blocks

• Always lay from the finished surface, onto the prepared bedding.
• Use a string line, laser or screed rails for precise levels.
• A 3–5 mm joint is generally needed; blocks knocked tightly together can spall.

Laying patterns:

• Stretcher bond: suitable for pedestrian or light loading.
• Herringbone: better under vehicle traffic; it distributes shear forces more effectively.
• Interlocking industrial pavers: for high shear forces and industrial applications.

Cut with a diamond blade or block splitter. Avoid cut pieces smaller than 1/3 of a block in heavily loaded zones.

Step 7 – Jointing and compaction

1. Sweeping in dry, clean jointing sand or fine grit.
2. First sweep – make sure the joints are completely filled.
3. Plate compaction with a rubber mat (without the mat it is forbidden – it damages the blocks).
4. Re-jointing – the joint material settles.
5. A top-up a few weeks later is recommended.

Without compaction the surface never beds in properly – the blocks rock and shift.

Plant and tool list

Machinery:

• mini excavator, loader, dumper,
• plate compactor with rubber mat, reversible plate compactor,
• vibrating roller,
• water-cooled cutting saw,
• laser level or rotating laser.

Hand tools:

• shovel, rake, wheelbarrow,
• string line, stakes, marking spray,
• spirit level, laser level,
• screed bar, screed rails,
• rubber mallet, broom, block lifter,
• manual block splitter or diamond-blade cutter.

Weather and seasonal constraints

In the province of Málaga paving can be carried out practically all year round, but a few rules should be respected:

• Never spread the sub-base on a waterlogged or softened formation – after the torrential autumn rains (DANA episodes) the ground must be allowed to dry out.
• Bedding and jointing should not be carried out during heavy rain.
• In high summer heat it is better to work in the cooler hours; the concrete for kerbs needs curing and protection against drying out.
• In the inland comarcas (Ronda, Antequera) occasional light frosts occur in winter: do not work on frozen ground, although these episodes are rare and short.