Geotextiles are produced from chemically-resistant synthetic fibers to prevent biodegrading.  The fibers are made into a flexible, porous fabric by standard weaving machinery.  They are then knitted or matted together by heat-sealing or needle punching.  Although porous to water flow across their manufactured plane, their mechanical and hydraulic properties vary widely.


  • Separation — Prevents the mixing of two layers of soil having different particle sizes.  Performance criteria are AOS, tear, tensile strength, permeability, and permittivity.
  • Filtration — Retains fine particles while allowing water to flow through.  Acts as a filter rather than a drain.  Therefore, it is important to consider performance criteria such as AOS, permeability, and permittivity.   The physical properties of the fabric must also allow adequate flow, proper soil retention and resist clogging.
  • Drainage — Gathers and discharges liquids or gases not required functionally by structure.  Performance criteria are mass, transmissivity, and permeability.
  • Reinforcement — Provides a tensile element to the soil matrix, thus providing more competent structural material.  A geotextile must be able to transfer its strength to the soil it is reinforcing.  It must also maintain its strength for maximum effectiveness.  It must allow water to pass through readily while filtering out fine materials that can weaken the soil.  Performance criteria are grab, elongation, tear and mass.
  • Protection — Shields synthetic membranes from puncture, abrasion and perforation.  Also referred to as a cushion layer.  Performance criteria are puncture resistance, mass, and burst strength.

Non-Woven Geotextiles

Non-woven Geotextiles are a felt-like material made from polyester or polypropylene staple fibers.  They are needle punched and then heat set.  Two main categories of non-woven geotextiles are available.  Civil series non-wovens meet typical weight strength and filtration properties, which is more cost-effective.  Environmental series non-wovens meet the minimum average roll values (MARV) which may be required depending on the project.  Please send us your specifications so we can help you determine the most cost-effective solution for your next project.

Light-Weight Non-Wovens

  • Functions — Separation and filtration
  • Weight — 3 oz – 5oz, roll widths 12.5’ and 15’
  • Applications — High flow rate and small opening sizes.  Used as a filter fabric around a subsurface drainage system.  Fabric collects fine sediments while filtering out water.  For use along highways, within embankments, and on athletic fields.

Medium-Weight Non-Wovens

  • Functions — Separation, filtration, and protection
  • Weight — 6 & 8oz, Roll width 15’
  • Applications — Specifically used for separation layers under rip-rap, in gabion baskets and under Envirogrid geocells.  Also to hold soils in place for permanent erosion control.

Heavy-Weight Non-Wovens

  • Functions — Protection, separation and stabilization
  • Weight — 10 oz./sy – 16 oz./sy,
  • Applications — Cushion and protect geomembranes while providing abrasion resistance.  Also used for stabilization under railroads to prevent the mixing of ballast with subgrade below.

Ultra Heavy-Weight Non-Wovens

  • Function — Protection and stabilization
  • Weights — Up to 100 oz./sy, roll widths up to 25’
  • Applications — High load applications such as the protection of landfill liners and cells, railroad sub-grade protection.  Also to wrap buried pipe and for environmental drainage control.

Recycled Green Non-Woven Geotextiles

IWT carries a complete line of GREEN non-woven geotextiles manufactured from post-consumer plastic bottles.  The green color of these polyester fibers can also be used as a high visibility demarcation layer.  In addition, they can be used towards LEED credit/certification for your project.  Typical weights range from 4.5 oz./sy up to 12 oz./sy.  Roll size is 12.5‘ x 400 or 15‘ x 300‘.  Please call us for more information.

Orange Non-Woven Geotextile Demarcation Fabric

Orange demarcation fabrics act as a visual dig barrier on construction, environmental and historical sites.  They also separate contaminated soils from clean soils before capping while providing a protective visual barrier for future excavations.  This is especially important on sites with underground utilities or other buried structures.

IWT also offers lightweight orange woven geotextiles and netting for these applications.  Please see our demarcation fabrics page for more information or call us at 609-971-8810.  We’ll answer your questions so you can select the most cost-effective option for your project.

Woven Geotextiles

Woven geotextiles are made from polypropylene or polyester fibers interlaced to create a unique fabric.  Slit-film wovens are manufactured with flat strands for strength while monofilaments have round fibers to create more uniform opening sizes for drainage applications.  High strength and high performance wovens can also be knitted or woven to achieve the desired performance characteristics.

Slit-Film Wovens

  • Functions — Separation, filtration, stabilization and reinforcement.
  • Excellent puncture and tear resistance as well as high tensile strengths.
  • Lightweights for separation of good to moderate subgrades.  Also for control of runoff and flow velocity, such as silt fences and temporary access roads.
  • Heavy weights for separation and reinforcement.  Also for the stabilization of weak subgrades for heavy loads or abrasive base material.
  • Applications — Stabilization of weak subgrades such as unpaved roads, parking lots, access haul roads.

Monofilament Wovens

  • Functions — Filtration, erosion control
  • Unique hydraulic characteristics – High percent open area (POA) allows water to flow through at high rates while filtering out and capturing sediments without clogging
  • High strengths for durability as well as survivability
  • Applications — Shoreline erosion control, leachate collection systems, drainage and curb inlet filters as well as geotextile tubes and filter bags.  Also bulkheads and silt curtains

High Strength and High Performance Wovens

  • Functions — Reinforcement, stabilization, filtration, separation
  • High soil interaction — Soil confinement/greater load distribution
  • High percent open area for long term free flowing filtration and drainage
  • Immediate load take up with low elongation, low creep and high tensile strengths
  • High seam strength — Weak soil conditions and demanding stabilization applications
  • Applications — Retaining walls, landfill liner reinforcement, extra steep earthwork, soil stabilization for rail and road construction.  Also for bulkheads and underwater
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Disclaimer: These guidelines are for informational purposes only and are intended as illustration or general information only and are not intended as a guarantee or warranty. IWT assumes no responsibilities in connection with the use of this information.