Repairing sunken pavers: what happens at each stage of the job

Why does the order of the steps matter?

Each stage of a paving repair depends on the one before it. A perfectly laid surface on a bed that was never corrected will sink again, and a well-prepared base is wasted if the joints are left half empty. Knowing the sequence also helps owners understand a quote and ask sensible questions about what is, and is not, included.

The method below is how we approach a typical lift and relay repair. Exact depths, materials and the size of the area depend on what we find once the blocks are up, which is why we describe the logic rather than fixed measurements.

Step 1 – How do you decide how much paving to lift?

We always lift more than the visible dip. The sunken area is surrounded by blocks that have tilted slightly towards it, and the edge of the hollow is rarely where the base failure ends. Lifting a margin of apparently sound paving lets us reach firm ground on every side and blend the new level into the old.

Before anything comes up, we photograph the pattern and, where it is complex, number or sketch the blocks so they return in the same arrangement. Herringbone and multi-size patterns in particular need care, because a single misplaced row shows clearly once the job is finished.

• mark the repair area beyond the dip on all sides
• record the laying pattern and any cut pieces at edges or covers
• lift the first blocks carefully, as they are the hardest to free
• stack the blocks nearby and clean old bedding off their undersides

Step 2 – What happens to the base once the blocks are up?

This is the most important stage and the one that separates a repair from a cosmetic fix. With the blocks removed, we dig out the old bedding and inspect the sub-base. Soft, wet or contaminated material comes out until we reach firm, stable ground, and at that point we can usually see the cause of the failure.

The correction depends on the cause. A thin sub-base is rebuilt with granular material placed and compacted in layers. Settled trench backfill is excavated and recompacted. Where water is the culprit, the fall is corrected and the outlet dealt with. If a root is involved, it is assessed before anything else. The guide to base failures lists the faults we meet most often.

Material removed at this stage is construction and demolition waste. In Spain it is governed by Royal Decree 105/2008 and Law 7/2022; the latter treats rubble from minor domestic building and repair works as household waste under municipal responsibility. Typical European List of Waste codes are 17 01 07 for mixed concrete and ceramics and 17 05 04 for soil and stones.

Step 3 – How is the new bedding layer prepared?

On top of the corrected base goes a thin, even layer of bedding grit. It is spread loosely and then screeded with a straight rail running on guides set to the final level, allowing for the small amount the blocks will settle during compaction. Nobody walks on the screeded bed; it is laid ahead of the blocks and worked from the paved side.

Getting the bedding level right is what makes the repaired patch disappear into the surrounding paving. It is also where the fall is set, so water runs to the channel or gully rather than back into the repair. A bedding layer that is too thick is a common fault, because it moves under load and lets the surface ripple.

Step 4 – Can the original blocks be reused?

In most repairs, yes. Concrete and stone blocks laid on a flexible bed usually come up undamaged and go back in exactly the same pattern. Reusing them keeps the colour and texture consistent, which matters on a driveway or terrace where newer blocks would stand out.

Chipped or cracked blocks are replaced. If the original product is no longer available, we look for the closest match and place replacements where they are least visible, for example under a parked car or at an edge. Blocks are laid from the existing paving outwards, tight to the string lines, keeping the joint width consistent with the rest of the surface.

Step 5 – Why are the joints filled before compaction?

Dry jointing sand is brushed into the joints so the blocks can lock against each other. A first fill goes in before compaction, so the vibration works sand down between the blocks rather than letting them shift. Without sand, blocks rock against each other and their edges chip. After compaction the joints are topped up again, because the first fill always settles. Empty joints are one of the main reasons paving loosens over time, and they are covered separately in our loose pavers repair page.

How long before the repaired area can be used?

Because block paving is laid on an unbound bed and compacted on the day, a repaired area can normally take foot traffic as soon as the surplus sand has been swept away. Vehicles are a different matter where the base has been rebuilt, and we advise on that case by case depending on what was replaced and how deep the work went.

For the first period after a repair, the joint sand keeps settling, especially after the first rain. A light top-up of the joints is a normal part of aftercare and does not mean the repair has failed. The aftercare guide explains what to look for and when to call us back for a check.

Step 6 – How is the repaired area compacted?

A plate compactor, usually fitted with a protective pad to avoid marking the surface, is run over the repaired area and a strip of the surrounding paving. This beds the blocks into the grit, closes the joints and brings the repair to the same level as the paving around it.

After compaction we check the level with a straight edge, top up the joints, sweep away surplus sand and look at how water would run across the surface. On a driveway we also check the transition at the garage threshold and the gate, where small differences are easiest to feel underfoot.

What about permits, safety and owners who are away?

Most private paving repairs are minor works. In Andalusia, Law 7/2021 (LISTA), article 138.1.a), places minor works of limited scope that do not need a project under a declaración responsable, but each town hall decides which procedure applies to a given job. Before work starts, check the current ordinance of your municipality or ask its planning department which route applies. Work touching the public pavement or a kerb drop normally needs its own municipal authorisation, requested under the same town hall's rules.

On site, Royal Decree 1627/1997 sets the minimum health and safety provisions for construction works, with or without a project. In practice that means keeping the work area fenced off, especially in communities with children or pool users nearby.

Many of our clients are not in Spain while the work happens. We agree the scope from photos, send pictures of the opened base so you can see the cause for yourself, and send pictures of the finished repair. Send us a photo and the approximate m² – free, no-obligation quote. For cost factors, see the paving repair cost page.

Frequently asked questions

Sources

• Law 7/2021 LISTA – minor works by declaración responsable (Vera town hall model)
• Construction and demolition waste – Royal Decree 105/2008 and Law 7/2022 (COA Málaga technical note)
• European List of Waste codes for construction waste (Govern de les Illes Balears)
• Royal Decree 1627/1997 – health and safety on construction sites (BOE)