There are a number of things to consider when selectiong a roof system. Of cource, cost and durability head the list, but aesthetics and architectural style are important, too.   The roof system for your home or building is one that balances these considerations.

The following summary is provided to assist property owners selecting the type of roof system that would best serve his/her purpose.

1. Built-up Roofing System (BUR): The "Traditional" Roof System.

Fabricated "on-the-job" by applying alternating layers of roofing "felt" and hot (or cold) asphalt.
It has been tried and proven its effectiveness.    It is easy to repair, and Cost Effective.

Its drawbacks are Its odor during installation, hazards associated with hot asphalt (450 degrees), and Requires regular maintenance.

2.Modified Bitumen Systems: The Tough and Durable Roofing System.

These are modern versions of Built-up Roof Systems embodying asphalt that contains modifiers in the "felts" which improves flexibility and longevity.   Various assemblies can be made using hot asphalt, cold process or heat welding.

Its advantages are Extra Longevity and Flexibility in the assembly compared to Built-up Roofing (BUR) System. It generally costs more than BUR.

3.Single-Ply Roofing System

As its name suggests, this is a roofing system consisting of one layer of material.
There are many types of single ply products, most of them designated by the initials of their principal chemical compound.   For example, one popular membrane material is PVC, a flexible version of polyvinyl-chloride.    Another rubber-like membrane is EPDM( ethylenepropylene-diene-monomer )

With these choices, it is imperative that the selection is tailored to the specific project.   Consult with your ATRC project manager for recommendations based on your project parameters.

Advantages of these Systems are Longevity, Lightweight and Flexibility.   Limitation of this system is High Initial Project Cost.   However, the Labor Content of the project cost is lower that would result in more value remaining in the roof.

4. Shingle Roofing Systems :

1) Asphalt Shingles posses an overwhelming share of the US steep-slope roofing market and can be reinforced with organic fiberglass materials.   Although asphalt shingles reinforced with organic felts have been around much longer, fiberglass-reinforced products now dominate the market.

A. Organic Shingles consists of a cellulose-fiber (i.e., wood) base that is saturated with asphalt and coated with colored mineral granules.

B. Fiberglass Shingles consists of a fiberglass mat, top-and bottom layers of asphalt, and mineral granules.

Asphalt shingle fire resistance, like most other roofing materials, are categorized by Class A, B or C. Class A signifies resistance.   Generally, most fiberglass shingles have Class A ratings, and most organic shingles have Class C ratings.

2) Wood Whingles and Shakes are made from cedar, redwood, southern pine and other woods; their look is popular in California, the Northwest and parts of Midwest.   Wood shingles are machine-sawn; shakes are handmade and rougher looking.

A point to consider: Some local building codes limit the use of wood shingles and shakes because of concerns about fire resistance.   Many wood shingles and shakes only have Class C ratings or no rating at all.   However, Class A fire ratings are available for certain wood shingle products that incorporate a factory-applied, fire-resistant treatment.

5. Tile Roof System : Clay or concrete - is a durable roofing material.

Mission and Spanish-style round-topped tiles are used widely in the Southwest and Florida, and flat styles also are available to create French and English looks.

Tile is available in a variety of finishes.   Tile is very heavy.   If you are replacing another type of roof system with tile, you will need to verify that the structure can support the load.

6. Slate Roof System : Slate is quarried in Vermont, New York, Pennsylvania and Virginia.   It is available in different colors and grades, depending on its origin.

Considered virtually indestructible, it is, however, more expensive than other roofing materials.

In addition, its application requires special skill and experience.   Many old homes, especially in the Northeast, are protected by this long-lasting roofing material.

7. Metal Roof System : Primarily thought of as a low-slope roofing material, has been found to be a roofing alternative for home and building owner with steep-slop roofs.   There are two types of metal roofing products: panels and shingles.   Numerous metal shapes and configurations exist.   Metal shingles typically are intended to simulate traditional roof coverings, such as wood shakes, shingles and tile.

Apart from metal roofing's longevity, metal shingles are relatively lightweight, have a greater resistance to adverse weather and can be aesthetically pleasing.    Some have Class A ratings.

NRCA recommends that

Before making a buying decision, you look at full-size samples of a proposed products, as well as manufaturer's brochures.   It also is a good idea to visit a building that is roofed with a paticular product in debate.