While there could be some initial cost-saving in laying new shingles over an old, aged roof, we generally don't recommend re-roofing. Old shingles also mean an old roof deck. By tearing off the old shingles, our licensed roofing contractor will then be able to spot any areas of instability or damage to the roof deck that may have been hidden by the shingles. We can replace any sections where there may be wood rot. Roof installation techniques and materials have also changed over the last couple of decades, and your old roof may not be up to code. "Re-roof" jobs may also not carry the same warranties as a full replacement.
Each shingle brand provides a different guideline for how long they expect their shingles to last. A properly installed roof will generally last up to 15 years with regular maintenance and inspection, especially after severe weather events.
The pricing for new roofs depends primarily on the square footage of the roof surface, the type of material you choose (asphalt, metal, cedar shakes, tile, etc), and the complexity of your roof (dormers, steep angles, etc.) Because we've been installing new roofs in the Puget Sound area for so many years, we have the experience and resources to help you decide on a quality roof solution that will suit your budget.
When you decide it's time to consider a new roof, consider first your budget and your goals. Metal roofs tend to last longer than asphalt shingles, but they cost more upfront and may not "fit in" with the neighborhood. Asphalt shingles are an affordable option, but even in that arena, there are choices that will determine the overall aesthetic and potential lifespan of the roof. Consulting a roofing contractor to help you make these choices is best. They'll have the experience to help guide you towards the best result.