Here is a chart of all the commercial roof types available (in a general sense) for use at this time:

Roof
System
System DescriptionIdeal System Recovery OptionsSystem ProsSystem ConsCost (1-10)Install Disruption (1-10)Warranty OptionsColour OptionsSystem Manufacturers
4-ply
built-up
Paper or Fiberglass
felts laminated
together with
asphalt. Membrane
is covered with pea
gravel or crushed
stone
2-ply MB, Single-PlyUsed over 100+ years. Rugged and durable.Field assembled. Smell of asphalt fumes during construction41010, 15, 20, 25 yrsDepends on ballast colour (pea gravel, crushed stone, granite, aluminized paint, etc)IKO, JM, Soprema
2-ply
modified
bitumen
(Con)
Modified Bitumen
(MB) is asphalt that
has had modifiers
added to it to give it
plastic or rubber-like
properties. The most
common types of
modifiers being used
are APP (Atactic
Polypropylene) and
SBS (Styrene
Butadiene Styrene).
Fiberglass or Kevlar
membrane
reinforcement.
3rd ply of modified bitumen, Single-ply membranes, Reinforced liquid applied acrylic membraneDurable, proven peformance, easy to repair Torch application of membrane may pose a fire risk7710, 15, 20, 25 yrsWhite, Grey, Brown, Green, Black, Silver, CopperIKO, JM, Soprema, Siplast, Firestone, Certainteed
Inverted
2-ply
modified
bitumen
Same as above but
membrane is directly
placed over deck.
Also know as a PMR
(Protected Membrane
Roof)
Modified BitumenMembrane is protected from puntures, wear & tear as well as heat fluctuationsDifficult to find leaks and to do repairs.7710, 15, 20, 25 yrsWhite, Grey, Brown, Green, Black, Silver, CopperIKO, JM, Soprema, Siplast, Firestone, Certainteed
EPDMEPDM  (ethylene
propylene diene
terpolymer) is an
extremely durable
single-ply synthetic
rubber roofing
membrane. Its two
primary ingredients,
ethylene and
propylene, are
derived from oil and
natural gas.
EPDM, Reinforced liquid applied acrylic membraneLow material costs, large factory assembled sheetsLow puncture resistance4210, 15, 20 yrsFirestone, Carlisle, Lexcan
Ballasted
EPDM
Same as above but
membrane is
ballasted with large
river stones.
EPDM, Reinforced liquid applied acrylic membraneLow material costs, large factory assembled sheetsDifficult to find leaks and to do repairs.4210, 15, 20 yrsFirestone, Carlisle, Lexcan
TPOThermoplastic
polyolefin (TPO)
single-ply 
roofing membranes
are among the
fastest growing
commercial roofing
products.
TPO, Reinforced liquid applied acrylic membraneLow material costs, large factory assembled sheetsLow puncture resistance4210, 15, 20 yrsWhiteFirestone, Carlisle, Lexcan
PVCPVC (Polyvinyl
Chloride). PVC sheets
are produced by
calendaring, spread
coating or extruding,
and typically are
reinforced with
polyester or glass-
fiber mats or scrim.
Can only be recovered with PVClarge factory assembled sheets minimize field assembly requirementsCost7210, 15, 20, 25, 30 yrsAny colourSika-Sarnafil
KEE KEE (Ketone Ethylene
Ester) is a polymer
with elastomeric
properties and
favorable melting
properties for
thermoplastic
processing.
It is manufactured
solely by DuPont™,
under the brand
name Elavloy®
Can only be recovered with KEEExtremely puncture resistant. High fire resistance.Cost7210, 15, 20, 25, 30 yrsAny colourFibertite