What Is a Silt Fence and Why Do You Need One for a Home Build?

Updated: Jul. 07, 2021

Made of posts and permeable fabric, silt fences help protect the watershed and infrastructure by keeping soil runoff in its place. Learn more here.

You’ve thought about siding, roofing, landscaping materials and the pros and cons of the various types of driveways. All are important. But have you made plans to install a silt fence? If not, take a step back and do it now — it’s a must for any new home build.

Most jurisdictions require silt fences at all construction sites. Without them, you could find yourself dealing with a clogged-up sewer and a mess of sediment pouring into the street. If you or your contractor skip this step, fines are likely, along with annoyed neighbors.

What Is a Silt Fence?

A silt fence differs from typical types of fences. It’s a temporary barrier employed at construction sites for erosion control, to “retain the soil in disturbed land,” according to Environmental Protection Agency (EPA). It keeps the soil you are digging and moving during your home build from winding up on roads and in rivers, lakes, streams, ponds and estuaries.

You’ve probably seen silt fences when driving by residential and commercial construction sites. They certainly aren’t anything you’ll want to leave up once construction is complete — porous fabric (known in the industry as a geotextile) held in place with posts. Proper design and placement are critical, with lots of digging, measuring and trenching involved.

Types of Silt Fences

Though there are several types of silt fences, only a couple are commonly used on home construction sites. When installed properly, all are sturdy and should keep sediments away from your local roads and/or watershed.

Standard Staked Silt Fences/Types A and B

This is the most basic of silt fences, and the one you are most likely to install. The difference between Types A and B is the width of the fabric and the length of the posts. A Type A fence requires 36-inch fabric and a minimum post length of four inches. Type B is 22 inches and three inches, respectively. Otherwise, the design is basically the same, and both varieties feature wooden or PVC posts.

Type C Silt Fences

Also known as wire-back silt fences, Type Cs are constructed with 40-inch metal or steel posts and 36-inch fabric, according to Dyersburg, Tennessee’s erosion control handbook. They are typically recommended for home builds adjacent to creeks, streams and ponds because the metal posts provide extra reinforcement.

Do I Need a Type A, B or C Silt Fence?

The type of silt fence your home build requires depends on various factors. Consult with your local building inspections department before you proceed to confirm requirements, design and materials. Many cities like Faribault, Minnesota list detailed specs for silt fences right on their website, so you can easily access and download the information you need.

How Much Does a Silt Fence Cost?

The cost of a silt fence is minimal compared to the overall cost of your home — not to mention the environmental costs and fines involved in skipping it.

The real cost will depend on the length of your fence and the materials used. You can sometimes find complete kits for 300-foot type C silt fences at home improvement retailers for less than $1,300, or a 50-foot roll of silt fence fabric for less than $15. You can also buy components individually from wholesalers and retailers specializing in erosion control, where basic wooden posts are often less than $2 each.

Keep in mind that construction supplies are in short supply and many items are backordered, so the things you need could be hard to track down.

If you hired a general contractor for your home build, the cost of silt fence materials and installation will probably be incorporated into your overall bid.

Can I Install a Silt Fence Myself?

Seasoned DIYers with knowledge of erosion control and landscaping can install a silt fence. The difficult part? Digging the trench, which is best done with the help of an excavator.

Be sure to track down your local requirements and regulations, educate yourself on the EPA’s silt fence best practices and find a good set of instructions. However, this is not a project to experiment with if you are a beginner — the stakes are too high. If you have any doubts about your ability to build a proper silt fence, consult a pro.