Cold and snow during the winter months can translate to additional maintenance needs on an acreage in the spring. One of the first things to tend to after a long winter is the driveway. Driveways often require repair or even partial reconstruction after a winter of snow removal. The following article discusses maintenance of your driveway.
Driveway surfaces are generally one of three types – concrete, asphalt or gravel. Concrete is obviously the most durable and handles frequently scraped surfaces, but is not a common choice for Iowa acreages. Asphalt requires sealing every few years to prevent deterioration. Gravel driveways are the most common type of farm driveway and require a compacted gravel base of at least 8 inches and some ongoing maintenance to ensure a long life.
Following a winter of blading snow from the driveway, the first step is to take a good look at your driveway and determine what, if anything, needs to be done. Take a garden rake and rake loose gravel that was pushed into your lawn with a snowplow and return that to the driveway. Do you have potholes, heaving or an extreme loss of gravel that requires replacement?
Under each driveway, there is a subgrade, or the natural soil existing there. A good driveway then has 8-12 inches of ¾ to 3 inch crushed stone on top and another 4 inches of compacted fine material on top of that.
To maintain a driveway, it is important that the subgrade can drain water adequately. Soils lose bearing strength as moisture increases, as is obvious when trying to drive through mud.
The MidWest Plan Service (MWPS) is a university-based publishing cooperative dedicated to disseminating research-based, peer-reviewed, and un-biased publications that support the outreach missions of the 12 North Central Region land-grant universities plus the U.S. Department of Agriculture (USDA). MWPS offers publications on everything from ventilation to construction to maintenance of farm and acreage buildings, as well as water and septic systems, wiring, crop production and more.
One such publication, Living on Acreages, What You Need to Know, covers things such as lot development, utilities, pests, maintenance schedules and driveway construction and maintenance.
The manual offers specific recommendations on driveways to ensure long-term viability. “Crown a gravel drive surface in the center of the road with a surface slope of half an inch per foot (4%) to encourage good surface drainage. Maintain the surface to prevent ruts, potholes and gravel ridges at roadsides that can trap water and encourage infiltration into the subgrade.”
Gravel driveways with poor crowns trap water, causing the crust to become saturated and break up, causing first damage and then deterioration of the driveway itself.
If potholes have occurred, widen out the section and fill the hole with layers, compacting each layer of gravel as it is added.
If the water is consistently a problem in your driveway, you probably have a drainage problem and tile must be installed to divert the water away from the driveway. Culverts should be utilized to direct flowing water underneath the driveway, such as the farm/acreage entrance from the road.
According to the MWPS manual, many states, counties and townships have permit requirements that specify the diameter, length and installation process for a driveway culvert. The most common culvert is made from corrugated metal pipe 26 feet long with a 15-inch diameter.
If new gravel is required, there are several sources throughout Iowa that will deliver trucks of gravel to your acreage.
A quick estimate to calculate the amount of new gravel you need into cubic yards is to take length (in feet) x width (in feet) x desired thickness (in feet - ideally .167 to .5 foot thick, depending on the condition of the driveway). Divide that number by 27 to obtain cubic yards and then add 4 percent to compensate for additional compaction.
Additional tips on maintaining your driveway can be found in the Living on Acreages: What You Need to Know manual, https://www-mwps.sws.iastate.edu/catalog/country-rural-living/living-acreages.