Will sealing fix sunken pavers?

Reading a sunken area from the bottom up shows which layer moved and which one a sealer touches.

• The subgrade: the soil underneath, the first layer Tech Spec 6 names when it traces a depression to settlement.
• The granular base: the layer above the subgrade, the other one Tech Spec 6 names for that settlement.
• The bedding sand: the layer a sand set paver is laid on, which Tech Spec 6 says can deform under wheel loads where it is too thick, or wash out.
• The pavers: the surface that shows the low spot.
• The sealer: a coat on the pavers that soaks into the joint sand to some extent, the top layer and the only one a sealing reaches.

The layers under the pavers are defined in full at paver base.

The maintenance guide ICPI and CMHA publish names the causes, and every one of them lies under or between the pavers.

Tech Spec 6 says depressions “are caused by settlement of the underlying subgrade or granular base, often from inadequate compaction,” and names other factors: a saturated base or soil, excessive bedding sand thickness deformed from wheel loads, or washed out bedding and joint sand. Rutting is the same kind of low area in a wheel path, typically caused by settlement of the subgrade or base under repetitive wheel loads. The guide's repair for a depression begins by identifying the source in the bedding, base or subgrade, and ICPI's construction guide adds that adequate compaction will minimize settlement.

Tech Spec 6 separates noticing a low spot from measuring one.

Tech Spec 6 says “Standing water and stains can be used to visually identify depressions,” though their boundaries and depth should be measured with a straight edge or string line. Rain on the pavement, it adds, readily identifies rutting, settlement and ponding. For pavers in low severity depressions, its repair is that they “can be removed, the settlement adjusted, and the units reinstalled with no wasted paving materials or unsightly patches.”

Measuring a low area and lifting its pavers is installation work, and nothing in a sealing does either. The paver cleaning page draws the same line for sealers and stabilizers under joint sand, weeds and the Naples rain.

ICPI's description of a sealer's job stays at the paver surface it is applied to.

What ICPI Tech Spec 5 credits a sealer with happens in the paver surfaces, where it limits what water, stains, oils and dirt can soak into, and ICPI's glossary adds enhanced color and, in some cases, reduced abrasion. None of those reaches below the paver. ICPI's warning about a poorly draining base makes the direction plain: a sealer applied over a base that drains poorly can become cloudy, which is the base acting on the sealer, not the reverse. A clouded sealer is taken up under why sealed pavers turn white, cloudy or slippery.

A paver that rocks or has drifted at an edge rather than sunk has its own mechanism and its own answer under will sealing fix loose pavers.

The repair Tech Spec 6 describes is a construction step, not a finish.

Tech Spec 6 sends restoration work to installers, naming CMHA's certified paver installers and an experienced paver installation contractor as the ones to guide a reinstatement. Timing a sealing around a landscaping project, which can move soil and irrigation near a driveway, is answered under sealing before or after landscaping, and joint sand lost to concentrated runoff flows, one of the causes Tech Spec 6 names for sand loss, is covered under why is the sand washing out of my paver joints.