From Asphalt Shingles to Zinc Strips

Why Do Roofers Need To Remove Your Old Roof During A Replacement?

One of the messiest and most labor-intensive parts of installing a new roof is removing your old one. When you replace your asphalt shingle roof, your roofers must remove your old shingles and underlayment before proceeding with the replacement. This process can take a substantial amount of time and will usually produce a lot of construction debris.

Since reaching your old decking can be such a large project, you may wonder why it's necessary. A roof restoration (or reroofing), which involves installing new shingles on top of your old ones, avoids this step altogether. This article will discuss why this step is critical and how removing your old roof makes a replacement more durable than a simple restoration.

Roofing Layers Explained

Manufacturers produce roofing systems in varying complexities, and some roofing systems may include extra layers of frost protection or other additional features. However, the simplest roofing systems will always have an underlayment installed on your roof decking, with asphalt shingle strips on top. These three layers ensure proper drainage and protect the decking from water that seeps under the shingles.

The underlayment is one of the most commonly misunderstood parts of a roofing system. This layer doesn't provide complete waterproof protection but acts as a secondary barrier. Your shingles' primary job is to keep water off your roof, but the underlayment can act as a stopgap if your shingles suffer damage or heavy rains allow some water to flow underneath them.

These added layers are important because your roof decking is so vulnerable to moisture. Any water that reaches your decking can lead to wood rot, reducing the structural integrity of your roof. Wet decking can also warp, creating ugly ripples and causing shingles to loosen and fall off. Ultimately, these problems will lead to more leaks and more problems.

The Importance of Removing Your Old Roof

As your roof ages, water will likely seep below your shingles. Your underlayment will provide some protection, but damage to your decking is almost inevitable. By installing new shingles on top of your old ones, you will do nothing to address these problems. While you may protect your roof from additional damage, existing deck problems can greatly shorten the lifespan of your roof or even lead to new leaks.

By removing your old roof as part of the replacement process, your roofers can carefully examine the condition of your decking. Roofers can remove damaged or rotting decking boards, providing a solid foundation for your new underlayment and shingles. While time-consuming, this process ensures that your new roof will last as long as possible.

Note that reroofing may be appropriate in some circumstances. However, you should always rely on the experience of a qualified roofer to make this determination. If your roofer suggests that a full tear-off replacement is the best option for your roof, taking this more time-consuming and costly route will ultimately pay off in a more durable and reliable roof for your home. 

For more info about roofing services, contact a local professional.