How to Position a Snow Fence to Block Snow

Snow fencing effectively keeps snow off roads and driveways, reducing the amount of plowing you have to do to keep the area clear. Snow fencing along roadways improves winter highway safety. Iowa State University's Local Technical Assistance Program reports that snow fencing along Interstate 80 in Wyoming reduced accidents caused by poor visibility by 80 percent. In order for snow fencing to be effective, you must know where to position it to block the snow.

Purchase snow fencing either 4 or 6 feet high. The taller the fence, the more snow it will block, but the more it will cost. The Iowa Department of Transportation uses 4- to 6-foot fencing along state highways. You can purchase this size of fencing at home improvement stores. This height is also easier to handle than much taller fencing.

Multiply the height of your fencing by 35. This is the distance your fence needs to be from the area you're trying to keep clear of snow, according to Iowa State University. This is enough space for snow to collect behind the fencing, and between the fencing and the road or driveway. If you place the fencing closer, you risk directing more snow onto the road or driveway.

Leave a gap of 6 to 12 inches between the bottom of the snow fence and the ground. The New Hampshire Technology Transfer Center explains this gap allows wind to flow under the fence and helps keep the fence from being buried in drifts.

Extend the fencing past the area you need to protect. Iowa State University reports this helps prevent wind from whipping snow around the fencing and onto the road or driveway. The Iowa Department of Transportation extends snow fencing 20 feet past the roadway. The New Hampshire Technology Transfer Center recommends extending the fencing at least 50 feet.

Erect the fence on the side of the roadway toward prevailing winter winds. This will be the side on which the highest drifts have accumulated in the past.