A roof system is the full grouping of coverings that make up your roof which includes the waterproof covering, roof insulation, a vapor barrier and a roof deck.

Roof systems and materials are generally divided into generic classifications: low slope and steep slope. Low slope roofing includes water impermeable or weatherproof types of roof membranes installed on a slight slope. Steep slope roofing includes water-shedding types of roof coverings installed on more steep slopes.


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 provides 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 six typical classifications of steep slope roof coverings.

  • Asphalt Shingles

  • Clay Tile and Concrete Tile

  • Metal Roof Systems for Steep-Slope Applications

  • Slate

  • Wood Shakes and Wood Shingles

  • Synthetic


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."

  • Roof Covering: The roof covering is the external watershedding material.


Source: National Roofing Contractors Association

PROBUILTCO is a Cary, NC roofing & siding contractor providing interior & exterior renovation services to Raleigh-Durham and surrounding areas of North Carolina.

PROBUILTCO Construction & Land Technologies

10030 Green Level Church Road

Suite 802-1083

Cary, NC 27519

PROBUILTCO | BBB Better Business Bureau
PROBUILTCO | HomeAdvisor
PROBUILTCO | Thumbtack
  • w-facebook
  • Twitter Clean
  • Google+ Clean

© 2013 - 2018 by PROBUILTCO | Pro Built Construction & Land Technologies, LLC. All Rights Reserved. 

PROBUILTCO Construction & Land Technologies | Cary, NC General Contractor | Interior & Exterior Renovation & Construction

(919) 642-3792