To understand which geotextile is right for your project, you must first understand how they are made.
Woven Geotextile: The Workhorse of Strength Woven geotextiles are manufactured by interlacing polypropylene tapes or multifilament yarns on a loom, similar to weaving cloth. This process creates a fabric with extremely high Tensile Strength. The primary function of woven geotextile is Reinforcement and Stabilization.
If you are building on soft soil, such as a swamp or clay subgrade, a woven geotextile is your best friend. It acts like a belt, holding the soil together and distributing the load of the overlying fill. It is particularly effective in constructing steepened slopes or retaining walls where the soil needs structural support.
However, woven fabrics generally have lower permeability compared to non-woven. While they are excellent at holding things together, they are not the best at moving water. Some woven fabrics are slit-film types, which can be prone to creep (long-term deformation) under constant load, so selecting the right grade is essential.
Non-woven Geotextile: The Master of Filtration As discussed previously, non-woven geotextiles are felt-like materials. They are excellent at allowing water to flow through while filtering out soil particles. Their strength lies in their thickness and ability to withstand installation damage.
Non-woven fabrics are typically used where drainage is a priority, such as in French drains, beneath concrete slabs, or on erosion control blankets. They are more flexible and conform better to uneven terrain than woven fabrics.
Making the Decision Ask yourself these questions:
1. Is the primary goal to stop soil from moving sideways and provide structural support? -> Choose Woven.
2. Is the primary goal to allow water to pass while filtering soil? -> Choose Non-woven.
In many complex projects, a combination of both is used. For instance, a woven fabric for stabilization at the bottom and a non-woven fabric for filtration on top.
Conclusion There is no "best" material, only the "right" material for the job. By understanding the physics behind woven and non-woven geotextiles, you can optimize your design for safety, efficiency, and cost.
