Why Reycle Shingles?
As landfill availability decreases and tipping fees increase, solid waste generators
are becoming more interested in finding alternative ways of managing shingle waste.
This site discusses the recycling of asphalt roofing shingles, or “composition shingles”
including shingle quantities, composition, processing, products, and products made
with recycled asphalt roofing shingles.
Asphalt shingle scrap can be used in a variety of products, including:
* Asphalt pavement
* Road and ground cover
* Aggregate base and subbase
* New roofing
* Cold patch for potholes, sidewalks, driveways, etc.
* Fuel oil
Processing Steps
To prepare shingles for use in new products, the shingles must be ground to a specified
size, and contaminants removed.
Grinding may be easier in the winter when the asphalt is more brittle. If the shingles
begin to stick together in hot weather, or from the heat of the equipment, spraying
with water or blending with sand or gravel may help.
Depending on the equipment used, primary grinding may yield 2” or 3”-minus size
pieces. Secondary grinding may be required to make smaller pieces if needed; for
example, aggregate base may require 3/4”-minus, and asphalt pavement may require
1/2”-minus or 1/4”-minus.
Depending on the use, the shingles may have to be sieved after grinding, to conform
to grading requirements.
For virtually all uses, contaminants must be removed. Possible contaminants may
include:
- Metals, which can be removed by a rotating magnet.
- Wood, which sometimes accompanies shingles when the plywood is also replaced in
a re-roof job.
- Wood can be removed by hand, or floated off in a water flotation unit.