This article will cover the treatment depth, drainage, surface profile, surface treatment, and typical timeline for unpaved road and pad construction projects.
Treatment Depth
The biggest factor to keep in mind when choosing the treatment depth for unpaved roads and pads is the traffic weight and volume that will travel on the surface.
You have three options when choosing a treatment depth:
1. Light traffic
For light-duty traffic, such as residential roadways that see mostly passenger vehicles, apply Perma-Zyme to a depth of at least three inches.
2. Regular traffic
For areas that see regular traffic from medium to heavy weight vehicles, such farming roads or rural roads with consistent semi truck traffic, treat to a depth of at least six inches.
3. Heavy traffic
For heavy industrial areas that see only extremely heavy weight traffic, such as mining or logging vehicles, treat to a depth of nine to 12 inches.
The treatment depth can change how to compact the soil. See the APPLICATION PROCEDURE section for instructions on compacting the soil.
Failure to treat the area to the proper depth during application can result in failures. Customers should contact their sales representative for questions regarding the depth of their application.
Drainage
Prior to construction, project owners must consider drainage. If not, water will stand on the road or pad and expedite surface wear. We recommend that forming ditches or trenches along the sides that are lower than the road or pad. These ditches will encourage water to flow away from the treated surface, helping elongate its lifespan.
Surface Profile
To have proper drainage, the surface must be shaped properly. It is necessary for proper functioning and also to ensure a long surface life and prevent safety issues such as standing water or flooding.
A slight crown running at the centerline will force water to move toward the ditches. We recommend that you follow proper transportation department guidelines for the region and that the profile not be so steep as to cause traffic issues.
On turns, the surface must be higher at the outside edge. This will force the water to drain to the inside of the turn.
Surface Treatment
Some customers add a gravel topcoat to unpaved, Perma-Zyme treated areas. We typically recommend a topcoat that is one to two inches thick, but the thickness will depend on different uses and preferences.
There are two options for applying a gravel topcoat:
- Add a gravel topcoat during compaction. In this case, the compactor works the gravel into the soil’s surface, and the soil bonds around it. This helps lock in the gravel to prevent material loss.
- Add a gravel topcoat after the Perma-Zyme treated surface cures. Wait for the soil to cure for at least 72 hours before applying gravel; applying gravel too early could prevent the soil from properly curing. Before adding the topcoat, spray a dilution of one part Perma-Zyme to 10,000 parts water (1:10,000) onto the treated area to help the gravel adhere to the surface.