Single-ply membrane roofs (TPO, PVC, and EPDM) are typically fastened to commercial buildings in one of two ways: mechanically attached or fully adhered (there are others but these are the most popular). Virtually all roofs sit on top of a layer of insulation or cover board that rests between the single-ply membrane roof and the structural roof deck.


Here is a quick comparison:     

                                                

  CATEGORY

MECHANICALLY ATTACHED

FULLY ADHERED

WINNER

WIND UPLIFT:

Great wind uplift resistance (depending on attachment method)

Superior wind uplift resistance

FA

HAIL RESISTANCE:

Good resistance (depending on substrate)

Superior resistance (depending on substrate)

FA

INSTALLATION COST:

Less expensive

More expensive

MA

INSTALLATION TIME:

Quicker

Slower

MA

INSTALLATION TEMPERATURE:

Any temperature

Warmer temperature

MA

ENERGY EFFICIENCY:

Lower due to air intrusion and fluttering of the membrane

Higher – acts as an air barrier

FA

DURABILITY:

Medium

High

FA

So which is best?

  • That all depends on your budget, type of building, and your performance expectations.  
  • A Fully Adhered system will out perform a Mechanically Attached system every time.
  • When it's time for a new roof, always consult with an experienced and trusted roofing contractor to determine the best system for your building.


Pro Tip: Mechanically Attached and Fully Adhered both require proactive preventative maintenance programs to prevent hazards from becoming leaks and to prolong the life of the membrane. Manufacturer’s require a maintenance program to keep the warranty in good standing. Rhoden Roofing offers a preventative maintenance program called RoofCare.  RoofCare is designed to save building owners money, increase the lifespan of the membrane, and reduce headaches that come from unexpected & preventable leaks.


Fully Adhered Illustration:

Mechanically Attached Illustration: