Why You Should Never Just Put Shingle Over Existing Shingles: Suggest A Tear-off

Replacing a roof is a significant investment, and it requires careful consideration of how the process should be carried out. Many homeowners wonder if it’s acceptable to simply add new shingles over existing shingles. Adding new shingles over old ones can lead to a host of issues, from reduced roof lifespan to potential structural damage.

Laying new shingles over old ones prevents you from inspecting the roof deck for damage. Hidden problems like rot and leaks can go unnoticed, leading to costly repairs down the line. Additionally, adding extra weight to the roof can stress the structural integrity of your home.

Ventilation is another critical factor affected by this practice. Roof ventilation is vital for maintaining a healthy roof structure, and layering shingles can hamper proper ventilation. This can result in trapped moisture, increasing the risk of mold growth and further damage.

Fundamentals of Roof Replacement

Replacing a roof involves critical decisions about the materials used and whether to perform a complete tear-off or opt for reroofing. These choices affect both durability and cost.

Understanding Roofing Materials and Structures

The choice of roofing materials impacts the longevity and performance of the roof. Asphalt shingles are commonly used due to their affordability and ease of installation. Metal roofing, wood shakes, and slate offer different benefits but also come with varying costs and lifespans.

The roof structure includes the roof deck, often composed of plywood or oriented strand board (OSB), and sheathing, which provides the necessary support for the shingles. Proper shingle installation on a sturdy roof deck ensures longevity and protection from the elements.

Tear-off involves removing all existing shingles and inspecting the underlying structure. This allows for the replacement of damaged roof decking or sheathing, ensuring a solid foundation for the new roofing material. Tear-off is beneficial for identifying and repairing hidden issues.

Risks of Layering New Shingles Over Old

Layering new shingles over old shingles can lead to several issues including increased weight causing structural concerns, hidden damages that can exacerbate future problems, and potential complications with warranties and building codes.

Weight Concerns and Structure Integrity

Adding a second layer of shingles significantly increases the weight of the roof. Roof sheathing and trusses are designed to hold a certain load. When this load is exceeded, it can compromise the integrity of the entire structure.

Over time, the added weight can cause the roof to sag. This sagging may not be immediately noticeable but can result in structural damage. In extreme cases, it might even lead to a collapse.

It’s important to consider that the original roof was engineered to support only one layer of shingles. By adding more weight, risks to the structure are compounded, potentially leading to costly repairs.

Hidden Damage and Future Problems

Laying new shingles over old ones can mask underlying damage. Issues such as rot, mold, or water damage in the roof sheathing are concealed, making them harder to detect and repair.

This hidden damage can worsen over time. Moisture trapped between layers can accelerate the deterioration of roofing materials. It may also lead to mold growth, posing health risks to occupants.

Moreover, the old shingles’ issues are not resolved, but merely covered. This can lead to more extensive repairs or even complete roof replacement sooner than anticipated.

Complications with Warranty and Building Codes

Installing new shingles over old shingles can void manufacturer warranties. Most manufacturers require proper installation to maintain their warranty terms. Non-compliance with these guidelines means any future shingle failures might not be covered.

Furthermore, this practice can violate local building codes. Many building codes specify that only one layer of shingles is permissible. Non-compliance can result in fines or mandated correction, adding financial and logistical burdens.

For homeowners considering resale, a roof that doesn’t adhere to building codes or has voided warranties can be a significant deterrent for potential buyers, affecting property value.

Implications for Lifespan and Costs

Replacing shingles directly over existing ones can lead to immediate savings, but it might also result in long-term financial and durability concerns.

Short-Term Savings vs. Long-Term Expenses

Some homeowners consider putting new shingles over the old ones to reduce labor and disposal costs. This approach can save $1,000 to $2,000 initially by avoiding the removal and disposal of existing shingles.

However, these savings can be deceptive. Covering old shingles can mask underlying issues such as rot or leaks, which might need costly repairs later. Additionally, increased weight from the extra layer might stress the roof structure, leading to potential damage.

Costs saved now can result in higher future expenses, including structural repairs and a shorter lifespan for the new shingles.

Best Practices for Roof Replacement

Selecting the appropriate contractor and materials is essential for a successful roof replacement. Understanding the roofing process ensures the work is done correctly and in compliance with local building codes.

Choosing the Right Contractor and Materials

When selecting a contractor, make sure they are licensed, insured, and have positive reviews or references. A qualified roofer will know local building codes and have experience with various roofing products. You can always contact the licensed and insured roofing contractors at Industry Elite Services to get more information on how they can help you. IES works with roofers in Naperville and has roofers in Aurora Illinois that can help you determine the best path to go when replacing your roof.

Choosing quality materials like underlayment, flashing, ridge vents, and ice and water shields is crucial. They contribute to the roof’s durability and performance. Investing in high-quality shingles and other materials can prevent future issues and prolong the roof’s lifespan.

Understanding the Roofing Process

The roofing process begins with a thorough inspection of the existing roof to assess its condition.

Next, workers should completely remove old shingles and materials to expose the deck. This step is vital for identifying and repairing any damage before new materials are installed.

Workers should then install each layer properly, including underlayment and flashing, to prevent leaks and other issues.

After that, they should add ridge vents and ice and water shields for ventilation and protection against moisture.

Throughout the process, workers must comply with local building codes. This ensures safety and effectiveness.