A silt sausage is a geotextile tube filled with aggregate that traps sediment from stormwater runoff while letting clean water pass through. They sit around drain inlets, along kerb lines, and at the base of disturbed slopes on construction sites across Australia.

Also called silt socks, filter tubes, or sand sausages, these products are a standard part of erosion and sediment control (ESC) plans required under EPA guidelines in every Australian state. They are reusable, UV resistant, and far quicker to deploy than many alternatives.

This guide covers what a silt sausage is, how to install one, where to place them on site, and how they compare to silt fences and other sediment controls.

What Is a Silt Sausage and How Does It Work

A silt sausage is made from non-woven geotextile fabric formed into a tube shape. The tube is filled with coarse aggregate (typically 10-20mm blue metal) or clean gravel to give it weight and structure. The geotextile filter tube lets water pass through while trapping suspended sediment particles on the upstream side.

The filtering action works because the aggregate inside creates thousands of tiny passages that slow water velocity. As stormwater passes through, suspended soil particles settle out and are captured. Clean water exits the downstream side.

Key features of silt sausages

• Non-woven polypropylene fabric rated at 90-100gsm for durability and UV resistance
• 150mm diameter when filled, sitting low enough to avoid tripping hazards
• Pre-cut or roll lengths available in 1m, 2m, and 50m rolls for any site layout
• Reusable across multiple projects when properly maintained
• No trenching required for installation, unlike silt fences that need posts driven into the ground

Because they conform to the ground surface, silt sausages seal better around drain grates and kerb returns than rigid products. They also handle foot traffic and light vehicle crossings without losing their shape.

Where to Use a Silt Sausage on a Construction Site

Silt sausages work best as secondary or perimeter controls around specific drainage points and along flow paths. They are not a replacement for primary controls on large-scale earthworks, but they are the right tool for targeted sediment capture.

Common placement locations

• Around stormwater drain inlets to prevent sediment entering the drainage network
• Along kerb and gutter lines where sheet flow carries sediment off disturbed areas
• At the base of stockpiles to catch material washed off soil, sand, or mulch piles
• Around concrete washout areas to contain high-pH runoff
• Across shallow swales and channels as inline check dams to slow flow and settle sediment
• Along site boundaries where runoff exits the property onto roads or neighbouring land

On residential building sites, a typical layout includes silt sausages around every drain inlet within the site boundary, along any kerb line receiving runoff, and at the downhill edge of any exposed soil.

How to Install a Silt Sausage

Installing a silt sausage is straightforward and does not require specialised tools or heavy equipment. If you are using pre-cut lengths like the 1m geotextile filter tube or the 2m filter tube, the process takes minutes per unit.

Step-by-step installation

1. Clear the placement area. Remove loose debris, rocks, and vegetation so the silt sausage can sit flat against the ground surface.
2. Fill the tube with aggregate. Use 10-20mm blue metal or clean gravel. Fill to about 80% capacity so the tube remains flexible enough to conform to the ground.
3. Position the silt sausage. Place it across the flow path or around the drain inlet. Push it firmly against the ground to eliminate gaps underneath.
4. Join multiple lengths. For longer runs, butt the ends together tightly or overlap by 150-200mm. Secure joins with cable ties or wire through the geotextile.
5. Anchor if needed. On steeper grades or high-flow areas, use steel fastening pins through the tube fabric to prevent movement.
6. Check for gaps. Walk the full length and press down any sections that are not flush with the ground. Gaps underneath will let sediment-laden water bypass the control.

For bulk installations, the 50m filter tube roll lets you cut to any length on site. This is more cost-effective for large commercial or civil projects than buying individual pre-cut units.

Silt Sausage vs Silt Fence

Both silt sausages and silt fences are standard sediment controls on Australian construction sites. They serve different purposes, and most ESC plans use both.

The main advantage of a silt sausage is speed. You fill it, place it, and it starts working. There are no posts to drive, no trenches to dig, and no risk of the fabric sagging between supports in a downpour.

The main advantage of a silt fence is height. At 770-860mm above ground, it can pond more water and handle greater sediment volumes across long perimeter runs.

Silt Sausage Maintenance and Reuse

A silt sausage only works if it is maintained. Sediment builds up on the upstream side over time, and if it is not cleared, water will flow over the top instead of through the filter.

Maintenance checklist

• Inspect after every rain event and remove accumulated sediment from the upstream side
• Check for undercutting where water has eroded a channel beneath the sausage
• Reposition if shifted by heavy flow or site traffic
• Replace aggregate if the fill material has become clogged with fine sediment
• Check fabric integrity for tears, UV degradation, or punctures from site debris

When the project finishes, silt sausages can be emptied, hosed clean, and stored for the next job. The non-woven polypropylene fabric is UV stabilised, so it holds up across multiple deployments as long as the fabric is not physically damaged.

Choosing the Right Silt Sausage Size

All Stake Supply stocks geotextile filter tubes in several lengths to suit different site requirements. The right choice depends on how many drain inlets you need to protect and whether you are running continuous lengths along kerb lines.

For most residential building sites, the 2m filter tube is the most practical size. It wraps around a standard drain inlet with enough length to seal both sides. Larger civil and commercial projects benefit from the 50m roll, which you cut to length on site and avoid waste.

Other Sediment Control Products That Work With Silt Sausages

A silt sausage handles drain protection and localised sediment capture. But a complete erosion and sediment control plan usually requires several products working together.

• Silt fences for long perimeter runs along downhill site boundaries
• Coir logs for slope stabilisation and check dams in drainage channels
• Sandbags for diverting flow paths and building temporary bunds
• Hay bale bags for additional inlet protection and sediment traps
• Geotextile filter fabric for lining sediment basins and wrapping aggregate drains

All Stake Supply has been a family-owned Australian supplier since 1976, with over 1,000 erosion control and site products in stock at the St Marys NSW warehouse. Browse the full sediment control range or contact the team for trade pricing on bulk orders.