Road Maintenance Activities

Cement Treated Base  

Spokane County began this process in 1999. The intent of these projects is to improve the underlying structure of the road and create an all season road. This process eliminates the closing of a road due to the freeze thaw season. This process decreases the high cost of maintaining these roads which are utilized frequently by heavy equipment.

This process involves a contractor pulverizing the existing asphalt in to a 3-inch minus material then adding dry Portland cement to the surface. This matter is then mixed with water to a depth of 8-10 inches. A 3 shot bituminous surface treatment is added to the road surface. This process does require that we close the road to local traffic only due to a curing time of about 2 weeks. Weight restrictions are in force during this period of time.

Standard Chip Seal   

Chip sealing is the most common preservation method in Spokane County. Chip Sealing is usually used to pave long stretches of rural roads, but has also been used on urban roads with success.  Visit our Chip Seal page for in depth information on the process and to view a map of scheduled chip sealing routes here:: Chip Seal 

Fog Seal  

This process is used to rejuvenate the asphalt surface which degrades and oxidizes with time due to environmental and other conditions. The fog seal is applied to the surface with a small amount of emulsified oil (50% diluted with water). The oil fills in the crevices and small cracks and helps to extend the life of the existing pavement.

Crack Sealing  

To combat the effects of water penetration into the sub grade, Spokane County applies a flexible crack sealant into and over cracks that are ¼” wide or greater. Cracks are sealed before overlaying, fog sealing, or chip sealing a road. When the crack filler dries it leaves the crack sealed from any further infiltration, extending the life of the road a few more years or until the next scheduled repair or replacement. Arterial roads are evaluated yearly for crack sealing candidates.

Gravel Roads - Rehabilitation and Restoration   

The rehabilitation process involves re-ditching, repairing or replacing culverts, fixing soft spots, shaping and in some cases widening the road. These roads usually receive 4 inches of new base rock and 3 inches of new top rock.

The preservation process involves regrading, light ditching and applying 2-4 inches of top rock to the existing surface. These roads are prioritized by traffic and need due to maintenance problems.

Asphalt Patching  

(Pavement removal and replacement) - When an area of road surface is damaged it is repaired and then a layer of hot asphalt mix and base rock area applied. The arterial roads are a priority. Roads to be chip sealed, fog sealed or overlay require these repairs.

Asphalt Overlay Program  

This process involves grinding some of the old asphalt off and relaying new asphalt. Spokane County overlays approximately one to two miles of road per year. This is used as preservation for our urban arterials.

Grind & Inlay Program  

Old pavement is ground or removed to a depth of about two inches and replaced with new asphalt. The grindings (removed asphalt) are recycled for future use.

This process is used for residential roads that have too many defects to make it cost effective to apply a slurry seal. This process involves grinding the existing asphalt, freshening up the rock or sub-base, fixing major curb, sidewalk and drainage problems and then applying new asphalt.