In general, it is recommended to remove old roofing felt (also known as underlayment or tar paper) when replacing a roof. Here are a few reasons why removing the old felt is typically advised:

  1. Assessment of Roof Deck: Removing the old felt allows for a thorough inspection of the roof deck. This helps identify any underlying issues, such as rot, water damage, or structural problems, that may have been concealed by the old underlayment. Addressing these issues before installing new roofing materials ensures a solid foundation for the new roof.
  1. Moisture Management: Over time, moisture can accumulate between layers of roofing felt. By removing the old felt, any trapped moisture can be properly addressed. This helps prevent potential issues such as mold growth, rot, and deterioration of the roof deck.
  1. Improved Adhesion: Removing the old felt provides a clean and smooth surface for the new underlayment and roofing materials to be installed. This enhances the adhesion of the new materials, improving the overall performance and longevity of the roof.
  1. Weight Considerations: Adding additional layers of roofing felt can increase the weight load on the roof structure. By removing the old felt, you can reduce the overall weight of the roof, which can be beneficial for older or structurally compromised roofs.

However, there may be situations where leaving the old roofing felt in place is deemed acceptable. For example, if the existing felt is in good condition, without signs of damage or moisture issues, and the new roofing system can be properly installed over it without compromising performance, some contractors may choose to leave it in place. It’s important to consult with a professional roofing contractor who can assess the specific condition of your roof and provide expert advice tailored to your situation.

Ultimately, the decision to remove or leave the old roofing felt depends on factors such as the condition of the existing underlayment, local building codes, and the recommendations of the roofing professional you hire. Speak to our experts at My Roofers Auckland today!