How To Install A Silt Fence
Simple steps to minimize erosion on your build site.
A half day
$150 - $400
IntroductionSilt fence is easy to install, and it’s also easy to do it wrong. Poor installation makes it ineffective. Here’s how to correctly install silt fence for your next project involving earth disturbance.
- 3-lb. maul
- Staple gun
We moved a lot of dirt to prepare our building site. We did it in a specific and strategic way, digging the foundation and basement while keeping the rest of the soil in place with silt fencing.
That’s the point of silt fencing – soil control. When well-placed and properly installed, the simple woven-fabric fence allows water to seep through while it holds back dirt and sediment. This prevents the land you’re disturbing from eroding into the lake or river or whatever’s next door. The beautiful lake just downhill doesn’t want our silt and dirt.
Silt fence is easy to install, and it’s also easy to do it wrong. Poor installation makes it ineffective. Here’s how to correctly install silt fence for your next project involving earth disturbance.
Note: This process is specific to our build in northern Wisconsin. While some of the steps transfer to other locations, check with your county or state for your specific rules.
Project step-by-step (6)
Buying Silt Fence
Silt fencing is sold in rolls, often with wooden stakes attached at eight-foot intervals; that’s the standard for many applications like ours. Buy the rolled-and-staked fence fabric in 50-ft. or 100-ft. rolls, as much as you need for your site. A 100-ft. roll with stakes attached costs about $50 at home centers.
Because pre-staked silt fence may sit in store inventory for long periods, check the integrity of the stakes, especially at stores with outdoor storage where wood may have been exposed to weather. You can also buy silt fence fabric and stakes separately.
Lay Out A Path
Lay out and mark the path for your silt fence, knowing it's intended to prevent silt from washing downhill off your worksite. You install silt fence in line with, not perpendicular to, the contour of your site. Install the fence run below the areas you’re disturbing.
Avoid creating large U-shaped fenced-in low spots where rainwater and sediment could collect. You may need to stagger fence runs, arranging them in J-shaped layouts, to avoid areas where water and sediment could flow over the top of a stressed fence. Create the same J-shape with the final end runs of the fence material and stakes.
Dig A Trench
For the entire run of your silt fence, dig a trench at least four inches deep. A V-shaped trench is easiest if you’re digging by hand, but a 4-in. x 4-in. square trench is good, too.
Place the lower eight inches of fabric into the trench; most fence fabric will have a red printed line on it noting that depth. The fence stakes should be on the lower or downhill side of the trench, and the fabric in the trench will run into the uphill side.
When the fencing is all in place, refill that trench and bury the bottom of the fabric.
Set The Stakes
As you move along burying the bottom of the fence fabric, pound the fence stakes into the ground every eight feet. We used a 10-lb. maul. Silt fence should stand at least 14 inches above the ground; check the regulations in your area. Where two sections of silt fence meet, overlap the fence ends to cover a span of two posts.
If you’re installing separate fence material and stakes, secure the fabric to the stakes. It’s easy to staple the fence material to wooden stakes. If you’re using steel stakes, attach the fabric with plastic tie wraps or wire fasteners.
Backfill The Trough
Once all stakes are in place, backfill the trough you dug and make sure the uphill side of the fence fabric is buried. Use a compactor and tamp the soil firmly over the fabric. You don’t need to place dirt behind the fabric and the stakes. Just make sure the stakes are solidly in the ground to keep the fence from collapsing.
Maintain The Fence
You’ll need to check your silt fence and make sure it’s maintaining shape and structure after rainy weather. Once the ground is stabilized and erosion is no longer a threat, you can pull up stakes and remove the silt fence.