If your roof is reaching the end of its lifespan, you'll generally have two options for a new roof installation: tearing off the old one or re-roofing over your existing shingles. Most contractors recommend the former, but why is removing your old roof important? This process may seem like a way to spend more on labor, but it's critical to getting a long-lasting roof installation.
While re-roofing might cost less upfront, these three advantages make a complete tear-off and replacement more durable and reliable.
1. Better Warranty Support
When you buy a brand-new car, you expect the manufacturer to cover the cost of any defects during the warranty period. Roofing materials come with similar guarantees. Asphalt shingles and other roofing materials will all come with manufacturer warranties that cover defects over a certain number of years. Most roofing contractors will also offer a warranty against installation defects.
However, these warranties typically come with requirements that include a proper installation. Many manufacturers will not provide the same warranty for re-roofing over existing shingles. Your roofer may also offer fewer guarantees when re-roofing since their installation can be affected the condition of your existing roof.
2. Decking Assessment and Repair
The decking (or sheathing) is the lowest layer of your roof. This layer typically consists of OSB (oriented strand board) or plywood boards attached to your rafters. Unsurprisingly, these wood boards are highly vulnerable to moisture. Leaks or pooled water on your roof can work their way under your shingles and underlayment, causing damage to these critical structural supports.
Any roof old enough to require replacement will likely have at least some water damage to its decking. By tearing off your old roof, your contractors can assess the condition of your decking and make repairs where needed. A new roof installation is the best time to make these repairs, and ensuring your decking is in good shape will also ensure your new roof won't fail due to existing decking damage.
3. Underlayment Replacement
Most roofing systems require an underlayment between the decking and the shingles. The underlayment protects the vulnerable decking and provides a good shingle base. However, roofers cannot install underlayment over an existing layer of shingles. If you choose to re-roof, you'll rely on the original underlayment beneath your old shingles.
On the other hand, a complete roofing replacement allows your contractors to remove the old underlayment and install an entirely new layer. A fresh underlayment provides maximum protection for your roof decking while ensuring that your new shingles have the solid base they need to last for many years.
For more information about roofing replacement, contact a local company.
