We’ve all built or repaired driveways or water crossings. According to earthmoving contractors, advance planning and a little extra money upfront contribute to long-lasting driveways that require minimal maintenance. Here are some tips:
1. A household driveway works well with a 12’-wide driving surface and with shoulders an additional 2’ wide on each side. Driveways that will carry 4WD tractors, semis and large equipment should have 24’- to 26’-wide driving surfaces with 2’-wide shoulders.
2. If you plan to mow the sides of the driveway, the slopes should be 3 to 1 or flatter (3’ of width for every 1’ of rise in height).
3. Build the top of the driveway “level,” and create a final crown with crushed rock or stone. A 2” crown is adequate for a 12’-wide driveway. A 3” to 4” crown is usually adequate for a 24’-wide driving surface. Excessive crown can lead to bottoming of low-clearance machinery.
4. Remove all sod and vegetation from the roadway’s path and scarify (rough up) the existing surface to allow the roadbed to bond with the existing soil. Build and compact the driveway in layers, with each layer of fill dirt not exceeding 9”. Once the finished grade is achieved, consider installing a layer of geotextile fabric. The fabric isolates the fill dirt of the roadbed from the material of the actual driving surface and reduces problems with potholes and frost boils. Some contractors like to use large crushed rock as the first layer on top of fabric to allow moisture to drain sideways, then apply a finer grade of stone for the actual driving surface.
Tow-behind box scrapers are the preferred way to level and maintain the final driving surface. Three-point-mounted blades mounted on tractors react to every vertical movement of a tractor’s front and rear axles. A tow-behind, hydraulically-adjustable box scraper can be used to slowly, precisely cut away high spots, fill potholes and smooth areas of washboard.
