Elite Roofing understands that, if you’re not a roofer or a jack of all trades, roofing systems might seem complex and their warranties confusing. This glossary of roof types is designed to help you understand what you currently have, what your options are and what might best suit your needs.
There are five generic classifications of low-slope roof membranes or systems.
- Built-up roof (BUR)/ four-ply membranes
- Modified bitumen two-ply membranes
- Single-ply membranes
- Thermoplastic membranes (e.g., PVC, TPO)
- Thermoset membranes (e.g., EPDM)
Most low-slope roof membranes have three principal components:
- Weatherproofing layer or layers — the weatherproofing component is the most important element because it keeps water from entering a roof assembly
- Reinforcement — reinforcement adds strength, puncture resistance and dimensional stability to a membrane
- Surfacing — surfacing is the component that protects the weatherproofing and reinforcement from sunlight and weather. Some surfacing provide other benefits such as increased fire resistance, improved traffic and hail resistance, and increased solar reflectivity
With some roof membranes, a component may perform more than one function.
There are four generic classifications of steep-slope roof coverings.
- Asphalt shingles
- Synthetic slate
- Cedar shakes
- Aluminum eavestroughs and downpipes
Steep-slope roof systems typically are composed of individual pieces or components installed in shingle fashion. Steep-slope roof assemblies typically consist of three primary parts:
- Roof deck — a roof deck is the structural substrate and usually is a wood-based material such as plywood or oriented strand board (OSB).
- Underlayment — underlayment provides temporary protection until a roof covering is installed and provides a secondary weatherproofing barrier. Sometimes underlayment is referred to as “felt” or “paper” but can include ice and water shield, synthetic or organic felt paper type membranes.
- Roof covering — the roof covering is the external water-shedding material