Choose woven geotextile by its required function first, then check the test method, machine and cross-machine properties, soil compatibility and installation survivability. Finally, calculate usable coverage after overlaps. A grab strength in pounds-force is not interchangeable with wide-width strength in kN/m, and neither fabric weight nor a single tensile number determines how much traffic a road can carry.
This guide covers strength, roll width and project type for buyers preparing a woven-geotextile specification. For a nonwoven purchase, use the nonwoven procurement checklist.
Tensile Strength: Read the Rating Before Comparing Products
Grab Strength and Wide-Width Strength Answer Different Questions
A label reading “200 lb” is incomplete without the test method, direction and reporting basis. ASTM D4632/D4632M measures grab breaking load and elongation. Material outside the gripped portion also contributes to the result; the number is not simply the strength of a one-inch strip. It is an index property used in quality control and acceptance.
ASTM D4595 evaluates wide-width tensile behavior and provides parameters relevant to reinforcement design. It is a valid, different measurement—not an inflated version of grab strength. Do not convert between the two by multiplying by roll width.
| Datasheet item | What to compare | Common mistake |
|---|---|---|
| Grab breaking load, N or lbf | Same test method, direction, condition and statistical basis | Treating the result as a truck-load rating |
| Wide-width tensile strength, kN/m or lbf/ft | Specified direction, strength and strain information | Substituting it for a grab-strength requirement |
| MD and CD/CMD | Machine direction along the roll; cross-machine direction across it | Assuming both directions have the same value |
| Elongation | Test method and strain at the stated load | Using elongation at rupture to predict road rut depth |
For force conversions only, 1 kN ≈ 224.8 lbf; therefore 1.4 kN ≈ 315 lbf. This arithmetic does not establish a universal 315-lbf product requirement. A value expressed in kN/m is force per unit width and cannot be compared directly with kN.
What MARV Means
MARV means minimum average roll value. FHWA describes the common statistical basis as the mean minus two standard deviations. It is not the lowest individual reading in a ten-roll sample. For illustration, a mean of 230 lbf and standard deviation of 15 lbf gives 230 − 2 × 15 = 200 lbf. This example is not a Jinseed test result.
Request the manufacturer’s declared MARV and supporting quality-control data. There is no universal rule that MD and CD must differ by less than 20%; directional requirements come from the application. A reinforcement design also considers working strain, installation damage, creep and durability, rather than using the ultimate strength without reductions.
Width: Calculate Effective Coverage and Handling Needs
Allow for Every Overlap
For equal-width parallel strips, the simple layout equation is effective coverage = n × W − (n − 1) × O, where n is the number of strips, W is roll width and O is the specified side overlap. Edge returns, end laps, curves and cutouts require additional material.
| Illustrative layout | Calculation | Usable coverage |
|---|---|---|
| Two 1.8 m strips; 0.9 m side overlap | 2 × 1.8 − 0.9 | 2.7 m, insufficient for a 3.5 m area |
| Two 2 m strips; 0.6 m side overlap | 2 × 2 − 0.6 | 3.4 m, insufficient for a 4 m pad |
| Two 5 m strips; 0.5 m side overlap | 2 × 5 − 0.5 | 9.5 m, insufficient for a 10 m area |
These overlap dimensions are calculation inputs, not installation recommendations. Select the actual overlap or seam detail from the approved design and supplier instructions. Soft ground, aggregate placement and anticipated movement can change the joint requirements. A loose overlap does not provide the same tensile continuity as a tested structural seam.
Check Roll Mass, Access and Cutting Layout
Nominal fabric mass can be estimated as width × length × GSM ÷ 1,000, with dimensions in meters and the result in kilograms. A 4 m × 100 m roll at 200–300 g/m² contains approximately 80–120 kg of fabric, excluding its core and wrapping. Confirm the actual shipping mass and available lifting equipment; do not assume a fixed number of people can safely carry it.
Compare supplier-confirmed widths and lengths against unloading access, turns, service penetrations and available working space. A wider roll can reduce joints, but it may increase trimming around obstacles. Draw the panel layout before ordering. An exactly 4 m wide sheet covers a 4 m width only before allowing for required edge details and tolerances.
Project Type: Match Function to Site Conditions
Driveways and Roads
For separation, the fabric helps keep subgrade soil and aggregate from mixing while satisfying the specified hydraulic requirements. For stabilization or reinforcement, additional design checks are needed. Provide subgrade information, drainage conditions, aggregate gradation, proposed base thickness and construction traffic before selecting a grade.
A 200-lbf grab value does not guarantee five to eight rut-free years, and a woven geotextile does not automatically replace a fixed thickness of aggregate. Prepare the subgrade, avoid driving directly on exposed fabric, and place the initial cover and compacted lifts according to the construction specification. Persistent pumping or rutting requires a review of the ground and pavement system, not simply a heavier roll.
Heavy-Duty Parking and Working Pads
Account for wheel or track loads, turning and braking, repeated traffic and the condition of the ground during construction. Installation survivability and long-term service performance are separate checks. Where AASHTO M288 is specified, identify the contract edition, application, relevant elongation category and all required properties; do not approve a product from one strength value or GSM alone.
Retaining Walls and Riprap
Distinguish filtration from soil reinforcement. A filter between soil and drainage stone is selected for soil retention, water passage, clogging resistance and survivability; it is not automatically the wall’s reinforcing layer. Woven products differ substantially in yarn construction and hydraulic performance. FHWA’s rockery guidance, for example, calls for nonwoven filters and excludes woven slit-film separation fabrics in that application. Do not extend that example to every engineered woven filter.
For wall filtration, see retaining-wall geotextile selection. Rock placement height, bedding, anchorage and joints must follow the applicable design; a high puncture value does not make uncontrolled rock drops acceptable.
Before Approving the Woven-Geotextile Order
- State the function, soil conditions and installation conditions.
- Specify the test methods, units, required directions and acceptance basis.
- Check hydraulic properties where filtration or drainage matters.
- Confirm net coverage, roll dimensions, shipping mass and joint details.
- Obtain traceable product documentation and resolve any substitutions before installation.
Use the geotextile test-report guide to check the submitted evidence. Where the design instead calls for a nonwoven filter or protection layer, compare the Jinseed nonwoven geotextile range against the specified requirements.
