It depends on the current roof system, roof age, and existing number of layers and composition of roof system. Repairs are commonly used to allow for extra time to plan for complete replacement.

Shake or wood shingle roofs rule of thumb last 20 to 25 years.
Most asphalt shingle systems typically last from 12 to 20 years.

Most roofs fail due to improper specifications and poor workmanship.

Static vents are roof vents that have no moving parts or power and rely on physics to allow for proper air flow in a properly specified and installed roof system.

Ventilation is necessary if there is airspace between an insulated living area and roof deck area. Most roofing product manufacturers require proper ventilation to maintain a warranty for their products.

Yes! Providing that there is no more than 1 layer of existing roofs.

Ideally it is better if the roof is removed. The Uniform Building Code states that only 2 layers of roofing material will be allowed on any residence. This sometimes varies by city and county Codes.

There is always the possibility when installing a new roof over the existing roof, that the old roof may carry an uneven look into the new roof.

There are many different types and styles of roofing materials available and selection should be a process of identifying proper needs and wants.

The slope of the roof, house style, and structure of the roof are the first consideration when selecting new roof materials. Then, select a product that will last to your expectations and fits within your budget while also providing the right look for your type of home to add to its curb appeal. The best approach is to work with an experienced project specifier that can assist in matching the right needs and wants. Since most roofs fail due to improper specifications and poor workmanship, selecting the right company to work with is critical to long term performance.