What does a roof do?

Roof - Wikipedia

Complete Guide to Roof Installation and Local Roofers.
A roof is the top covering of a building, including all materials and constructions necessary to support it on the walls of the building or on uprights; it provides protection against rain, snow, sunlight, extremes of temperature, and wind. A roof is part of the building envelope.

How does roof pitch affect cost?

Steep Sloped Roofs Versus Low Sloped Roofs | Which Costs More

Palau Roofing Contractors | Palau Roofers | Commercial Repair and ...
How Does Roof Pitch Affect Roofing Prices? For starters, the steeper the slope on a roof, the more shingles it will take to cover it. Asphalt shingle costs might be double on a 12/12 compared with a 4/12 roof. This is an important consideration if you're building a new home.

How do you know it's time for a new roof?

Do I Need a New Roof? | Owens Corning Roofing

Prime Six Roofing Ideas By Specialists - Homes Renovation Idea
Potential signs that your roof may need to be replaced:
  1. Shingle edges are curled or shingle tabs are cupped. ...
  2. Bald spots where granules are missing.
  3. Cracked shingles. ...
  4. Your roof is at least 20 years old; while many shingles today are produced for durability, many factors can accelerate the aging of shingles.