The 5 Rules of Silt Fence Installation
Silt fences are used to prevent sediment from migrating to private properties or natural bodies of water near construction sites. Despite their importance, however, their effectiveness is often compromised by improper installation. To ensure your silt fence does its job, follow these five installation guidelines.
1. Select the correct height
Silt fences consist of a permeable geofabric stretched between posts. This fabric lets water through while holding back sediment. To work properly, the fabric needs to be high enough. On flat sites with a slope of less than six per cent, a fence of at least 16 inches is required. The height of the fence should increase with the slope. However, never go above 28 inches, as it would increase the risk of flooding below the fence in the even it fails.
2. Select the right post type
Wood posts are almost always preferable to metal ones. Their increased surface area allows them to withstand side loads more easily. In addition, they make it possible to attach the fabric with wide crown staples, which are more secure than the plastic zip-ties used with metal posts. However, when the soil on the site is too hard to use wood, metal posts are an adequate substitute.
3. Space the posts correctly
The maximum distance between each post should always be 10 feet. However, it’s often necessary to reduce this distance, such as in curved sections and in very low areas. The general rule of thumb is that allowing for a distance of eight feet between each post will ensure the fence can withstand wind and water runoff. The cost of additional posts is usually offset by lower maintenance and repair costs thanks to the fence’s sturdiness.
4. Select the correct post length
Posts should be 16 inches longer than the above-ground height of the fence. There’s no point in going any deeper. Past 16 inches, both wood and metal posts will break from the resulting stress before being pulled out of the ground.
5. Install wire backing where necessary
Adding a wire backing will increase a silt fence’s strength and stability. It’s recommended that any sections located in high-load areas be reinforced with a wire backing, as these are the places where a failure is most likely to happen. When using wire backing, posts should be no further than six feet apart.
Get the right fencing contractor for the job
Construction sites can benefit from a range of fencing solutions. With 35 years of experience, City Fence can help you make your work site as safe and efficient as possible. Contact us today for a free estimate or to discuss your project.