Using a professional-grade fabric in retaining wall construction is important in ensuring the longevity of the wall. Scroll down to view details on the fabric referenced in the diagram below.
Geotextile Fabric for Retaining Walls: An Overview
When building a retaining wall, success isn’t only about the blocks. Beneath, behind, and above every wall should be a
geotextile fabric layer that manages water, prevents soil migration, and increases long-term durability.
This fabric acts as the hidden foundation of a healthy retaining wall system.
Finished Retaining Wall
What Does Geotextile Fabric Do?
Geotextile fabric is a woven or nonwoven material placed in key areas around a wall. Its purpose is simple but critical:
allow water to pass while keeping soil in place. Without it, water can wash fines into drainage stone, clog pipes, and
cause erosion or bulging behind the wall face.
In short, fabric separates and filters—it ensures that different construction layers (soil, gravel, drainage fill)
stay intact and perform their roles without contamination.
Fabric behind wall prevents soil from clogging drainage stone
Where Is the Fabric Installed?
Below the wall base: A layer beneath the compacted gravel base prevents subsoil fines from migrating upward and weakening the footing.
Behind the wall: Installed vertically between the drainage stone and the backfill soil, the fabric keeps soil from washing into the stone zone.
Above the wall: Placed over the top layer of drainage stone before topsoil, it protects the stone zone from contamination while allowing water to escape.
Together, these placements ensure the wall’s structure remains free-draining and stable for decades.
Installing a Retaining Wall
Benefits of Using Retaining Wall Fabric
Prevents soil migration: Keeps soil from clogging gravel or drain pipes.
Improves drainage: Allows water to pass freely while holding soil particles back.
Protects structural integrity: Reduces pressure buildup behind the wall by maintaining clean drainage zones.
Weed suppression: When used on top, fabric helps block weeds from growing through the wall cap area.
Cost efficiency: Extends wall lifespan, reducing repairs and rebuilds over time.
Case Study: Backyard Garden Wall with Drainage Issues
Challenge: A homeowner built a small 4-foot retaining wall without fabric. Within two years, water had washed soil into
the gravel zone, clogging the drain pipe and causing soggy soil and wall leaning.
Solution
Removed backfill and installed nonwoven geotextile fabric beneath the base, behind the gravel, and above the drainage zone.
Replaced clogged gravel with clean, angular stone.
Added new drain pipe wrapped in fabric for extra filtration.
Result
Wall stabilized and drainage restored.
Standing water eliminated even during heavy rains.
Homeowner avoided a costly full wall rebuild.
FAQs
Should I use woven or nonwoven fabric?
Nonwoven fabric is generally best behind walls since it has superior filtration. Woven fabrics can be used beneath the base if
separation strength is more critical.
Do I need fabric for short retaining walls?
Yes—while small walls don’t require geogrid reinforcement, fabric is always recommended to protect drainage zones and
prevent erosion.
Can landscaping fabric be used instead?
No. Weed barrier cloth is not engineered for structural drainage applications. Always use geotextile fabric designed for
retaining walls and soil separation.
