Horizontal Filter Fabrics and Protection Layers Checklist

The checklist

Materials & Delivery Verification

1. 1Confirm geotextile type, class, and mass per approved project specifications; verify roll tags against submittals; record manufacturer, lot numbers, and roll dimensions; photograph roll labels for evidence.
2. 2Inspect delivered rolls for tears, UV damage, moisture, or contamination; keep packaging intact until use; reject compromised rolls and document with photos and supplier notification.
3. 3Measure roll width with a steel tape (±10 mm) and confirm planned coverage layout fits drawing extents; record measurements and capture a layout photo.
4. 4Verify protection layer material (e.g., sand/fine gravel or geotextile cushion) meets gradation/thickness per approved project specifications; collect certificates of conformity; photograph stockpiles and labels.

Subgrade Preparation (Horizontal)

1. 5Grade and compact subgrade to design level; confirm with 3 m straightedge (max deviation 10 mm) and level survey (±10 mm); record readings and photos.
2. 6Remove protrusions/debris; proof-roll with low ground pressure equipment; acceptance: no exposed stones >25 mm and no pumping; photo evidence required.
3. 7Confirm surface is firm and dry-to-damp; no standing water; dewater or dry as needed; document moisture condition with photos before placing fabric.
4. 8Install perimeter wind control/anchors: trench 200–300 mm deep or sandbags at 2–3 m spacing; photograph trench dimensions or ballast grid.
5. 9Mark layout lines and machine-direction arrows on the subgrade using spray paint; reference control points; capture overview photos with markers visible.

Placement & Orientation (Horizontal)

1. 10Unroll fabric in the specified machine direction using a spreader bar and two-person crew; avoid dragging; acceptance: no wrinkles >25 mm; photo after placement.
2. 11Verify fabric face orientation (if applicable) per manufacturer datasheet; acceptance: correct side up; photograph manufacturer markings in situ.
3. 12Lightly tension and smooth fabric with push brooms/squeegee; ensure full contact with subgrade; acceptance: no bridging/voids; photo of smoothing operation.
4. 13Place temporary ballast (sandbags) along edges and laps at 2–3 m spacing to prevent wind uplift; photograph ballast spacing.
5. 14Only after inspection approval, place initial protection layer lift with low-ground-pressure equipment; target thickness 50–100 mm per specifications; verify with depth pins every 5 m; record readings and photos.

Overlaps & Seams (Horizontal)

1. 15Form shingle laps in flow direction; minimum overlap 300 mm; measure with a tape (−0/+20 mm tolerance); photograph measurements.
2. 16Stagger T- and end-joints by ≥500 mm; mark with chalk; verify with tape; capture joint layout photos.
3. 17Where traffic before cover is unavoidable, secure overlaps with plastic staples or sandbags at ≤1.5 m spacing; photograph fixings.
4. 18If sewn seams are specified, use double-thread lockstitch; perform a 1 m trial seam pull test per approved project specifications; log results and photos.
5. 19Patch around penetrations/cuts with geotextile extending ≥300 mm beyond opening; secure per specification; photograph patch dimensions.

Coverage, Protection & Damage Prevention

1. 20Confirm 100% area coverage; no gaps, fishmouths, or fold-unders; upload an overview photo grid showing continuous fabric.
2. 21Restrict equipment on exposed fabric; if crossing is necessary, use plywood/track mats; acceptance: no tire tracks or snags; supervisor sign-off and photos.
3. 22Place full protection layer before routine access; maintain uniform thickness (e.g., 75 mm nominal) checked with depth pins every 5 m; record all readings.
4. 23Prohibit turning wheels in place on first cover lift; brief crew and post signage; acceptance: no rutting or exposed fabric; photo verification.
5. 24Inspect during/after covering for tears or punctures; repair with patch extending ≥300 mm beyond damage; re-cover and photograph before/after; obtain supervisor approval.
6. 25Recheck overlaps after cover placement; acceptance: retained overlap ≥300 mm with no displacement; measure at random 10% of joints; record values.

Documentation & Handover

1. 26Upload roll numbers, delivery tickets, certificates, measurements, and photos to the checklist; acceptance: all fields complete; QA reviewer sign-off captured.
2. 27Mark as-built coverage extents on plan with chainage/coordinates; tolerance ±0.2 m to drawings; attach annotated sketch/photo overlay.
3. 28Capture digital signatures of foreman and inspector with date/time; export PDF/Excel with QR authentication; distribute to stakeholders and archive.

Preview the printable checklist

Preview page one below. Open the image or download the PDF for all pages.

At a glance

• Standardizes horizontal geotextile placement from subgrade readiness through coverage. Crews confirm machine-direction orientation, shingle laps, and full area coverage with measurable tolerances. Results: fewer punctures, consistent filtration/separation, reduced contamination, and clear photo evidence that withstands audits and supports payment milestones.
• Interactive online checklist with tick, comment, and export features secured by QR code. Field teams attach roll tags, overlap measurements, and cover thickness readings; reviewers trace approvals and timestamps, ensuring transparent, verifiable QA and rapid resolution of nonconformities without sifting through fragmented records.
• Focuses solely on horizontal filter fabrics and protection layers, excluding membranes and vertical work. Acceptance cues include 3 m straightedge flatness limits, minimum 300 mm overlaps, staggered T-joints, and controlled access. Real jobsite practices—sandbags, mats, and low-pressure equipment—limit damage and displacement during covering operations.

How to Use This Interactive Horizontal Fabric Placement Checklist

1. Preparation: Confirm latest drawings, approved project specifications, ITPs, and submittals. Gather tape measures, 3 m straightedge, depth pins, spreader bar, sandbags, mats, camera/PDF scanner, PPE, and low-ground-pressure equipment.
2. Open the checklist: Create a new section for the work area, enter roll numbers and material types, and assign responsible roles for placement, inspection, and sign-off.
3. Use interactive mode: Tick items as completed, add time-stamped comments, and attach geotagged photos for overlaps, thickness checks, and repairs directly in the relevant steps.
4. Quality capture: Record measurements, approvals, and trial results in the designated fields. Link evidence to plan locations or chainage for easy traceability during reviews.
5. Sign-off and export: Collect digital signatures from supervisor and inspector, then export the commentable record as PDF/Excel with QR authentication for distribution and archiving.

Subgrade readiness and fabric orientation drive durable performance

Horizontal geotextile performance starts with a smooth, firm platform. Grade to level and proof-roll to reveal soft spots; remove sharp debris that risks puncture. Use a 3 m straightedge to maintain a maximum 10 mm deviation, then confirm levels within ±10 mm. Mark layout lines and machine-direction arrows before unrolling so the fabric aligns with primary load or flow, as specified. Unroll with a spreader bar and two-person crew, avoiding drag that scuffs or snags fibers. Lightly broom to remove wrinkles and ensure full contact; bridging creates stress concentrators and sediment bypass. Temporary sandbags at 2–3 m intervals control wind uplift while you check orientation and face marking against the datasheet. On river training works, for example, a well-prepared bedding ensures the filter remains continuous beneath a riprap apron, preventing fines washout and settlement. Document all checks with photos of straightedge readings, layout marks, and face-orientation indicators for traceable QA.

• Maintain ≤10 mm under a 3 m straightedge.
• Confirm levels within ±10 mm design elevation.
• Pre-mark machine direction and fabric layout.
• Avoid dragging rolls; use a spreader bar.
• Ballast edges with sandbags at 2–3 m.

Overlaps, joints, and securing methods that keep soil in place

Correct overlaps stop fine soil migration. Use shingle laps in the flow direction with a minimum 300 mm overlap, checked by tape. Stagger T- and end-joints by at least 500 mm to prevent through-joint pathways. Where cover is delayed or traffic is unavoidable, secure laps with sandbags or approved plastic staples at ≤1.5 m spacing. For projects requiring sewn seams, adopt a double-thread lockstitch and run a 1 m trial seam pull test per approved project specifications, recording results. Around penetrations, place patches extending at least 300 mm beyond cuts. Keep wrinkles under 25 mm and fishmouths eliminated before covering. On drainage blankets under slabs, these controls maintain filtration continuity and bearing evenness. Photograph tape measurements, joint staggering, and any seam trials; link them to roll numbers so repairs or extensions remain traceable during future works or maintenance interventions.

• Shingle laps in flow direction; ≥300 mm overlap.
• Stagger T-joints/end-joints by ≥500 mm.
• Secure laps at ≤1.5 m when traffic occurs.
• Trial seam pull tests where sewing is specified.
• Patch penetrations with ≥300 mm extension.

Cover promptly and prevent damage during construction traffic

Filter fabrics and associated protection layers must be covered promptly to avoid UV exposure and accidental damage. Place the first protection lift—often 50–100 mm sand or fine gravel—using low-ground-pressure equipment. Verify thickness with depth pins every 5 m and avoid turning wheels in place. Where crossings are unavoidable before cover, use mats or plywood to distribute loads and prevent snags. Inspect continuously during covering; repair any tears with patches extending at least 300 mm beyond damage, then re-cover. Recheck overlaps after cover placement to confirm they remain ≥300 mm. On utility corridors, these practices keep fines from migrating into the sub-base, preserving pavement life and drainage performance. Document thickness readings, equipment type, and repair photos; secure supervisor approval and digital signatures to close out works with a complete, auditable record.

• Place 50–100 mm initial protection lift promptly.
• Use mats for any crossing on exposed fabric.
• No wheel turning on first cover lift.
• Repair tears with ≥300 mm patch overlap.
• Recheck overlaps after cover placement.