What kind of patches are done?
- Skin Patch - Skin patches are used when there's a large area of "spider webbing". It involves laying a thin skin of asphalt without milling or grinding down the underlying layer. It is also used to resolve water flow issues or to minimize ruts and uneven asphalt.
- Pothole Patch - Pothole patches involve manually installing new asphalt mix and compacting the area. During the winter season, a "cold patch" is used as a temporary fix until spring comes and a more permanent fix is done.
- Overlay Patch - An overlay patch is one where multiple conflicting patches are combined into one integrated patch. This option is a great alternative when a complete road replacement is not needed at the time.
What is the process?
Our Public Works department will blow out the debris, pour in the asphalt, lute it out smooth, then roll and compact it. They use either 4A or 4S type asphalt from St. Paul. 4A is used for bigger pothole patches and has more aggregate in it. 4S is more of a sand mix, uses less aggregate and used for skin patches. We use a 4-ton trailer to get the asphalt around the City, which means the more severe the road, the sooner they get to it. Minor patches will take longer to fix since the trailer can only hold so much and we get our asphalt from St. Paul, it's not made locally. With that, we make sure to use every last bit that is bought from St. Paul. No piece of asphalt goes unused.
Severity Of Roads
Our Public Works department works on potholes by their severity. The bigger the pothole, the faster it will be fixed.
How long before a pothole can be driven or walked on?
Potholes can be patched very quickly (some only take 5 minutes), but the asphalt comes out of the truck at 300-320 degrees. Most patches can be walked on or driven on right after, but just as a precaution, please avoid it for at least 30 minutes. If the pothole takes longer to cool, our Public Works department will stick around or provide the proper signage to make sure you avoid the area.
Walking Trail Potholes
If you notice an asphalt walking trail with a pothole or any heaving, let us know right away. Our Public Works staff don't walk these roads often, but you do. If you notice anything, let us know
here.
Sinkhole
A sinkhole is a depression in the ground that has no natural external surface drainage. When water from a rainfall moves down through the soil, rocks begin to dissolve by the groundwater circulating. With time, the underground space gets too big and eventually there is no support for the land above and the ground collapses. A sinkhole looks like a pothole from a distance, but up close, you'll see undermining beneath the surface. Sinkholes are mainly found near catch basins. This is because catch basins erode, water starts seeping into the asphalt and eventually the stone base supporting the asphalt collapses.
If you notice any type of pothole or sinkhole, let us know here.
