Single Ply Roofing, as its name implies, is a single layer of roofing material. It is a flexible or semi-flexible pre-manufactured membrane typically made of rubber or plastic materials.
In simple terms, they are sheet products that are in roll form. These sheets or membranes are then rolled out and attached to the roof three unique ways: adhesives ("fully adhered"), screws and plates ("mechanically attached") or weighted down with rock or pavers added on top of the sheet ("ballasted").
The term single ply roofing can be used to describe quite a few very different roof assemblies from modified bitumen to PVC. Primarily this term is used to describe newer roof membranes such as:
They are categorized as follows:
- EPDM (Ethyl Propylene Diene Monomer) is an elastomeric rubber roofing membrane.
- PVC (Polyvinyl Chloride) is an energy efficient, fiber-reinforced, lightweight roof membrane.
- TPO (Thermoplastic Polyolefin) is a high quality, reinforced membrane with superior tear strength and stability.
Thermosets are membranes that cannot be hot air welded and are mechanically fastened or adhered. EPDM membranes fall into this category.
Thermoplastic are membranes that can be hot air welded to form cohesive seams. PVC and TPO membranes are the most common types.
Hypalon is manufactured as a thermoplastic but cures over time and becomes a thermoset.
PVC and TPO membranes are both thermoplastic sheets, which mean that they can be heat welded. The welded seams of a properly installed thermoplastic membrane are usually stronger than the sheet itself.
Both PVC and TPO membranes are usually white although many manufacturers are now offering these in a variety of colors. The white sheets have benefits due to their reflective nature. Many testing and certification entities have labeled these as being âcool roofsâ due to their ability to lower interior temperatures and utility costs as compared to a darker roof type.
Why use Single Ply?
The application of single ply roofing has great advantages for the customer:
The biggest advantage to these single-ply systems are their light weight per square foot. This advantage makes them an ideal choice for retro-fitting over the existing roof. This allows for quicker installations, less disruptions to the building owner and cost savings. Many single-ply membranes are white and provide superior reflectivity which helps reduce A/C costs during the summer months.
- Rapid construction
- Cost Effective
- Safe, flame-free construction using hot-air welding, adhesives and fasteners
- High thermal performance using lightweight, thermally efficient rigid insulation
- Easy repair, modification and refurbishment
- Extremely durable
- Simple detailing to suit all situations
- Interfaces to other construction elements
- They offer long term warranties that can be purchased inexpensively