Single-Ply Membrane Recycling

Single-ply membrane recycling is the recovery of flat-roof waterproofing sheets, mainly thermoplastics such as PVC (polyvinyl chloride) and TPO (thermoplastic polyolefin), so the material can be reprocessed into new products. Thermoplastics can be melted and reformed, which makes them more readily recyclable than thermoset membranes such as EPDM rubber.

Roofcollect in Europe

Roofcollect is a collection and recycling system set up by ESWA, the European Single Ply Waterproofing Association, to recover end-of-life waterproofing membranes. It organizes collection in most European countries. Recovered thermoplastic membrane can be reprocessed into new products. Separately, the European PVC industry's VinylPlus programme works on collection and recycling of PVC more broadly.

Sources of material

• Installation offcuts and trimmings, which are clean and easiest to recycle.
• Tear-off membranes from reroofing projects, which may be contaminated with adhesives, dirt, ballast or insulation facers.

TPO

TPO membranes are blends of a thermoplastic (such as polypropylene or polyethylene), an elastomer or rubber, and usually a mineral filler such as talc. They are widely used in roofing because they resist UV degradation. As a thermoplastic, TPO can in principle be remelted and reprocessed, although post-consumer collection is less established than for metals.

Challenges

• Contamination from adhesives, coatings and attached insulation reduces recycled quality.
• Additives such as plasticizers, stabilizers and fillers vary between products and ages, which can complicate reprocessing.
• Logistics: large, light rolls of used membrane are costly to transport.
• Overlay versus tear-off: where codes and roof conditions allow, recovering an existing membrane rather than removing it avoids waste altogether.

Related approaches

Long service life, repairability and roof designs that allow layers to be separated at end of life all help reduce membrane waste.