Concrete Pavers: A Technical Reference
What a concrete paver actually is, what standard it has to meet, what thickness and base depth each application needs, and how they fail. Every number on this page is referenced to a published standard or to industry guidance, listed at the bottom.
Written by NexGen Remodeling & Building, CSLB #1127800. We install concrete pavers across Los Angeles and Ventura County. Last verified 20 August 2026.
What a concrete paver is
A concrete paver is a manufactured, pre-cast unit made from cementitious material, aggregate and admixtures, pressed and cured under controlled conditions. It is not poured on site and it is not the same material as a concrete slab, despite the shared name. Units are laid on a compacted aggregate base with a thin bedding layer, then locked together with joint sand.
The word that does the work is interlocking. Load applied to one unit transfers through the joint sand to its neighbours, so the surface behaves as a field rather than as a set of loose tiles. That is also why joint sand is structural rather than cosmetic, and why an empty joint is a real problem rather than an aesthetic one.
What the standard requires
Interlocking concrete pavers sold in the United States are specified under ASTM C936/C936M. These are the requirements a unit must meet.
| Property | Requirement | Note |
|---|---|---|
| Average compressive strength | 8,000 psi (55 MPa) minimum | No individual unit below 7,200 psi (50 MPa). |
| Water absorption | 5% average maximum | No individual unit above 7%. |
| Minimum thickness | 60 mm (2 3/8 in.) | Thinner units are not covered by the standard. |
| Freeze-thaw durability | ≤1.0% mass loss over 50 cycles | Effectively irrelevant in Southern California. Listed for completeness. |
| Length and width tolerance | ±1.6 mm (±0.063 in.) | This tolerance is why a machine-made paver field closes up tightly. |
| Height tolerance | ±3.2 mm (±0.125 in.) | Tighter than natural stone, which varies by its nature. |
The comparison worth knowing
A concrete paver must average 8,000 psi. A residential concrete driveway slab is typically specified at 3,000 to 4,000 psi, and a patio slab can be as low as 2,500 psi. A concrete paver is therefore roughly two to three times the compressive strength of the poured concrete it replaces.
Worth being precise about what that does and does not mean. It is a real difference, but it is not the main reason paver surfaces outlast slabs. The larger factor is structural behaviour: a segmental surface flexes at its joints instead of cracking, and a failed area can be lifted and reset rather than demolished.
Thickness and base by application
From CMHA Tech Spec 10. This table corrects a claim you will see repeated widely, including by contractors: 80 mm pavers are not required for a residential driveway.
| Application | Paver thickness | Aggregate base |
|---|---|---|
| Patios and walkways | 60 mm | Compacted aggregate, depth set on site |
| Residential driveways | 60 mm | Deeper than a patio, set on site |
| Vehicular traffic beyond residential | 80 mm | Engineered to the load |
The number that actually changes between a patio and a driveway is the base, not the paver. Both are specified to be compacted to 98% standard Proctor density per ASTM D698, which requires placing and compacting in layers rather than all at once a plate compactor only densifies so far below itself, so a single deep placement leaves a firm crust over loose material.
Local conditions push these minimums up. Expansive clay soils, common across parts of the San Fernando Valley and inland Ventura County, want more base than well-draining sandy ground near the coast.
Thru-mix and face-mix: why some fade and some do not
Two manufacturing methods produce visually similar pavers that age very differently.
A thru-mix unit carries the same blend of pigment and aggregate all the way through. It is simpler to produce. As the surface wears, the pigment dulls and the coarse structural aggregate beneath begins to show through at the face, which is what people are describing when they say concrete pavers "faded."
A face-mix unit is made in two layers: a top layer of concentrated pigment and fine, wear-resistant aggregate over a coarse structural base. The visible surface is engineered for appearance and wear, and the structural aggregate never reaches the face. Colour retention is substantially better.
If long-term colour matters to you, this distinction matters more than the brand name and more than the price. It is also not something you can see in a showroom sample, so it has to be asked about. We install lines from Belgard, Angelus Block, Acker-Stone and Orco, and we will tell you which method a given line uses before you commit to it.
How concrete paver surfaces fail
Almost every failure traces to one of four causes, and only one of them is about the paver itself.
- Inadequate base depth or compaction. The most common by a wide margin. Produces settling, units that rock underfoot, and low areas that hold water. Not repairable by resanding or sealing.
- Missing edge restraint. The perimeter has no neighbouring unit to press against. Without a restraint the edge migrates outward and the field loosens progressively inward.
- Joint sand depletion. Sand washes out slowly, faster in coastal damp. Once the level drops, load stops transferring between units and weed seed has somewhere to sit. This one is genuinely maintenance, and cheap relative to the alternative.
- Surface wear on thru-mix units. Colour dulls and structural aggregate shows at the face. Cosmetic rather than structural, and not reversible.
The practical test that separates the first from the third: walk the surface and put weight on individual units, particularly near edges and where vehicles turn. Nothing should rock. Low joint sand on a solid surface is maintenance. Low joint sand on a surface that moves is a base problem, and resanding it will not fix anything.
Where concrete pavers are the wrong choice
We install these for a living, so weigh this accordingly, but a reference page that only lists advantages is not a reference page.
- Up-front cost. Pavers cost more than a poured slab on day one, essentially always. If you are selling within a couple of years, or the difference is what stands between doing the project and not doing it, a slab is the right answer.
- Barefoot heat on a dark unit. Surface temperature tracks colour more than material. A dark charcoal pool deck will be unpleasant in an inland August regardless of what it is made of, and lighter natural stone such as travertine genuinely runs cooler.
- Where a specific natural material is the point. Concrete pavers imitate stone well, and a manufactured unit is still a manufactured unit. If the veining and irregularity of real stone is what you want, buy real stone.
- Cheap installations. A paver surface on an inadequate base fails faster than a slab would have. Done badly. This is the worse choice, not the better one.
Sources
- ASTM C936/C936M, Standard Specification for Solid Concrete Interlocking Paving Units, compressive strength, absorption, thickness and dimensional tolerances.
- CMHA (Concrete Masonry & Hardscapes Association) Tech Spec 10, Application Guide for Interlocking Concrete Pavements, paver thickness and aggregate base depth by application.
- ASTM D698, Standard Test Methods for Laboratory Compaction Characteristics of Soil Using Standard Effort, the reference for 98% standard Proctor density.
- Residential slab strength ranges are the values commonly specified for residential driveways, patios and flatwork rather than a single mandated figure; local building codes set the governing minimum.
If you find something on this page that is wrong, tell us and we will correct it. The page is only worth publishing if it is accurate.
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