Paver base compaction photo records before bedding sand

Direct answer

Before bedding sand is placed over a paver base, record the hardscape area, approved section, subgrade condition, geotextile or separation layer where required, aggregate base material, lift thickness, moisture condition, compaction equipment, pass pattern, density or proof evidence where required, surface tolerance, grades, drainage direction, base extension, edge restraints, curbs, utility structures, drainage inlets, photos, failed areas, corrections, rechecks, open exceptions, and release decision.

The record belongs before bedding sand because bedding sand should not become a hidden patch for a weak, wet, low, thin, loose, or poorly shaped base. Once sand is screeded, the crew may lose the visible evidence that would have shown whether the aggregate base was compacted, graded, drained, and accepted.

Use this field note as documentation guidance only. Project specifications, drawings, geotechnical report, paver manufacturer instructions, CMHA/ICPI guidance, civil or landscape architect direction, owner standards, local code, utility requirements, and site safety plan control the actual base material, thickness, density method, slope, drainage, bedding-sand thickness, and release authority.

Bedding sand should not hide base problems

A paver base can look almost finished while still being wrong. The aggregate may be short of thickness at the edge, loose near a utility lid, wet at a low corner, unsupported outside the edge restraint, too high at a doorway, or low enough that a crew is tempted to add extra sand.

Those conditions matter because the bedding layer follows the base. If the base is not accepted first, the paver installer may inherit a grade problem that cannot be corrected cleanly with sand. Later settlement, rocking units, ponding, edge creep, joint loss, and trip points often start as base issues that were covered before anyone wrote them down.

The photo record does not need to turn the foreman into the designer or geotechnical engineer. It needs to preserve the visible condition, test status, correction chain, and release boundary before the next layer makes the base harder to review.

Define the area and section

Start with the exact hardscape area. Record patio, walk, driveway, plaza, apron, courtyard, pool deck, parking bay, unit-paver roadway, phase, gridline, station, lot, or plan sheet reference. If the project has multiple paver sections, do not let one base photo stand for all of them.

Then identify the approved section that controls the base. Record paver type, bedding material, base material, base thickness, subbase if used, geotextile if used, drainage layer if used, edge restraint, curb, concrete collar, drain inlet, and any special load condition such as residential driveway, light vehicle, heavy vehicle, pedestrian, permeable, rooftop, or pedestal-adjacent work.

If the field condition differs from the plan, write the hold. Examples include unexpected soft soil, unsuitable fill, changed drainage slope, extra utility trench, different edge condition, missing curb, changed paver thickness, or a manufacturer detail that does not match the approved section.

Subgrade evidence comes first

The base record should show what it sits on. Photograph and record proof-roll observations where required, soft spots, pumping, rutting, organic material, unsuitable fill, standing water, excavation limits, elevation checks, utility trenches, repaired areas, and any geotextile or separation layer before aggregate hides the subgrade.

Do not write that the subgrade passed if the required reviewer has not accepted it. If the project requires a geotechnical observation, density test, moisture check, proof-roll signoff, or owner inspection, attach that evidence or list it as an open hold.

Subgrade exceptions should stay in the packet after repair. A soft area that was undercut, dried, stabilized, bridged with geotextile, or rebuilt with approved material explains why the finished base looks different from the original excavation photos.

Record base material, lifts, and moisture

For the aggregate base, record material source, material type, gradation or spec reference, delivery ticket where available, placed area, placed thickness, compacted lift thickness, number of lifts, moisture condition, weather, and whether the base was protected from contamination before release.

Lift records matter because a thick loose layer can look level while hiding poor compaction below. If the project limits lift thickness, the photo packet should show the lift sequence and the check that each lift was compacted before the next one was placed.

Moisture belongs in the record. Base aggregate that is too dry, saturated, frozen, contaminated, or pumping under the compactor should not be turned into a clean release note. Record the condition, correction, and recheck before bedding sand.

Tie compaction to equipment and location

A useful compaction note says more than compacted base. Record the compactor type, plate or roller model where required, crew, date, pass direction, pass count or pattern if tracked, lift, area, obstacles, and areas completed by smaller equipment because large equipment could not reach them.

Edges and obstructions need their own evidence. Photograph and record compaction around walls, curbs, steps, building edges, tree wells, utility boxes, drainage inlets, collars, poles, and tight corners. These are the areas where a smooth center field can hide loose margins.

If density testing is required, attach the report and map the test locations. If the project uses proof-rolling, plate observation, or another acceptance method instead, record the method, reviewer, observed condition, and release decision. Do not copy a density percentage from another specification unless it actually controls the project.

Grade and tolerance checks before sand

Base grade controls the finished paver surface more than many crews want to admit. Before sand, record stringline, laser, straightedge, slope, high point, low point, drain direction, door threshold, curb reveal, inlet collar, step transition, accessible route, and tie-in elevations required by the project.

The photo packet should show the check, not just the final appearance. Photograph the straightedge or grade rod at representative locations, the low corner, the drain or scupper equivalent, the edge restraint line, and the tie-in to fixed structures.

If the base is low, high, wavy, or out of plane, correct the base. Do not release bedding sand with a note that sand will make it up unless the project documents specifically allow the adjustment. Extra bedding sand may look convenient during installation and still telegraph movement or unevenness later.

Edge restraints and transitions are release items

A compacted base is not ready for bedding sand if the edge condition is unresolved. Record curbs, concrete bands, metal or plastic edge restraints, spikes, compacted base extension outside the paver edge, restraint elevation, restraint alignment, and whether the restraint is installed on the base or another approved support.

Transitions also need photos. Capture utility covers, cleanouts, drain inlets, trench repairs, existing slabs, asphalt tie-ins, steps, ramps, building thresholds, walls, planting beds, and landscape drainage features. These locations often decide whether pavers rock, shed water, or hold grade.

If an edge restraint, curb, inlet collar, or utility adjustment is not ready, make a partial release. Bedding sand can proceed only in the area that has a clear base, edge, and grade release.

Minimum paver-base release packet

Use the owner form, project QC form, geotechnical report, density report, and paver manufacturer's checklist first. Add this field packet where the required forms do not connect base acceptance to photos and bedding-sand release.

Before bedding sand checklist

Run this check before the bedding crew starts spreading or screeding sand.

• Confirm the hardscape area, plan detail, paver section, base material, and bedding-sand requirement.
• Attach subgrade proof, density, geotechnical, or owner inspection records required by the project.
• Photograph subgrade repairs, geotextile placement, utility trench repairs, and aggregate placement before they are covered.
• Record aggregate source, material type, tickets where available, lift thickness, placed area, and weather exposure.
• Record moisture condition and any drying, watering, removal, replacement, or rework before compaction release.
• Record compaction equipment, lift, pass pattern or observation method, density/proof evidence, and recheck results.
• Photograph tight-area compaction around edges, curbs, inlets, utility structures, walls, steps, and building faces.
• Check grade, slope, base thickness, straightedge tolerance, tie-ins, thresholds, inlets, and drainage direction.
• Confirm edge restraints, curbs, collars, base extensions, and utility structures are installed or clearly held.
• Do not use bedding sand to fill depressions, waves, missing base thickness, or unresolved grade problems.
• Mark partial releases and hold lines on photos or a plan.
• Name the person authorized to release bedding sand and the exceptions that remain open.

Failed areas need a correction chain

Do not replace a failed base note with a clean final note. Keep the original condition, photo, test, correction, and recheck. That chain is what proves the issue was closed before sand.

Examples include a wet pocket under the walk, a low base near a catch basin, loose aggregate at an edge restraint, thin base at a sawcut tie-in, a utility trench that settled under compaction, or a density test that failed at the driveway throat.

If the correction changes grade, base thickness, drainage direction, edge support, or utility elevation, update the release boundary and photos. A corrected base may still need a new approval before bedding sand.

Weak and strong base notes

Weak note: base compacted, ready for sand.

That note does not show the area, section, subgrade status, aggregate material, lift thickness, moisture, equipment, density or proof method, grade, edge restraints, photos, holds, or release authority.

Stronger note: South courtyard paver base checked before bedding sand from grid S1 through S6. Approved section L-4 used: concrete pavers over bedding sand and compacted aggregate base. Subgrade proof observation accepted after soft spot at S3 west was undercut, replaced with approved aggregate, compacted, and photographed. Geotextile placed at planter edge per drawing and overlap photos attached. Base installed in two lifts; tickets AB-214 through AB-218 attached. Moisture adjusted before final compaction. Plate compactor and small tamper used at wall, inlet CI-2, and utility lids. Density reports D-11 through D-15 passed at mapped locations; CI-2 east edge failed first check, received added aggregate and recheck D-15. Straightedge and laser photos show base grade to CI-2 and threshold T-1. Edge restraint ER-4 remains on hold at planter return; bedding sand released only for south courtyard outside the marked hold line.

The stronger note works because it preserves the failed condition, correction, recheck, and partial release. It also tells the bedding crew exactly where not to work.

Common mistakes

The first mistake is using final paver appearance as proof of base quality. A clean surface does not show lift thickness, moisture, density, subgrade repair, or edge support.

The second mistake is treating bedding sand as a leveling course for base defects. If the base is wrong, fix the base before sand unless the controlling documents say otherwise.

The third mistake is only photographing the center of the patio or drive. Edges, utility lids, collars, steps, walls, inlets, tight corners, and tie-ins need evidence because they are harder to compact and easier to dispute.

The fourth mistake is losing failed density or proof results after repair. Keep the failed result and the passing recheck so the record shows the defect was closed.

The fifth mistake is releasing the whole area when one edge or drain is still open. Partial releases are acceptable only when the hold line is clear and the next crew knows the limit.

Compliance and safety limits

This field note is not a pavement design, geotechnical approval, density specification, drainage design, accessible-route ruling, utility adjustment instruction, product installation manual, or code approval. The project specifications, drawings, manufacturer instructions, geotechnical report, civil or landscape architect, owner, AHJ, and qualified reviewers control the work.

Do not use this checklist to bypass utility locating, excavation protection, trench safety, compaction-equipment safety, traffic control, hearing protection, silica controls, dust control, PPE, slope access, weather limits, lifting controls, or site-specific safety procedures. Do not operate plate compactors, rollers, saws, loaders, or powered equipment without the training and controls required for the site.

Sources checked

• CMHA, Application Guide for Interlocking Concrete PavementsUsed for interlocking concrete pavement assembly context around bedding sand, compacted aggregate base, construction sequence, and application types.
• ICPI Tech Spec 2, Construction of Interlocking Concrete PavementsUsed for construction sequence, subgrade compaction, optional geotextile, aggregate base lifts, moisture, density checks, base surface, edge restraints, bedding sand, and compaction themes.
• CMHA PAV-TEC-009-13, Guide Specification for the Construction of Interlocking Concrete PavementUsed for compacted aggregate base under bedding sand, written density test results, base surface tolerance, dry/certified base, edge restraints, and the instruction not to proceed with bedding sand until base conditions are corrected.
• CMHA PAV-MAN-006-20, Construction Tolerances for ICPUsed for construction tolerance context around base variation, base thickness, compaction, base extensions, bedding sand, straightedge checks, and referenced ASTM standards.
• ASTM D698-12(2021), Laboratory Compaction Characteristics of Soil Using Standard EffortUsed for standard Proctor compaction-method context where project specifications reference ASTM D698.
• ASTM D1557-12(2021), Laboratory Compaction Characteristics of Soil Using Modified EffortUsed for modified Proctor compaction-method context where project specifications reference ASTM D1557.
• ASTM D2940/D2940M-20, Graded Aggregate Material for Bases or SubbasesUsed for graded aggregate base/subbase material context where specifications reference ASTM D2940.
• ICPI Tech Spec 17, Bedding Sand Selection for Interlocking Concrete Pavements in Vehicular ApplicationsUsed for bedding-sand material context, sand gradation, fines, durability, drainage, and the limit that bedding sand performance depends on more than appearance.
• OSHA, 29 CFR 1926.651, Specific Excavation RequirementsUsed for excavation and trenching safety boundaries around base preparation and utility work.
• OSHA, 29 CFR 1926.300, General Requirements for ToolsUsed for powered tool and equipment safety boundaries around compaction and cutting operations.

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