Most are needlepunched polypropylene staple or continuous filament, sold by weight in ounces per square yard or grams per square meter, commonly from about 4 to 16 oz/yd2. They stretch more than 50 percent before breaking, which helps them survive rough placement, and their thickness gives high water flow and puncture cushioning. Heat-bonded nonwovens are thinner and stiffer, with smaller openings.
Sixteen-ounce nonwoven geotextile goes on the liner first, nobody dumps stone on bare sheet.
Installers name nonwovens by weight, as in an 8-ounce, but a spec written on weight alone does not guarantee puncture or filtration performance.
Also heard as
- needlepunched geotextile
- nonwoven fabric
- felt
Related terms
Geotextile
Permeable fabric used with soil to separate, filter, drain, reinforce or protect, made woven, nonwoven or knitted.
Filtration
Letting water pass across a geotextile while holding back the soil particles it carries.
CBR puncture
Puncture test in which a 50 mm plunger is pushed through a clamped geosynthetic, simulating a stone pressing into it.
Mass per unit area
Weight of a geosynthetic per square meter or square yard, the basic identity check for geotextiles.